1/*
2** 2001-09-15
3**
4** The author disclaims copyright to this source code. In place of
5** a legal notice, here is a blessing:
6**
7** May you do good and not evil.
8** May you find forgiveness for yourself and forgive others.
9** May you share freely, never taking more than you give.
10**
11*************************************************************************
12** This header file defines the interface that the SQLite library
13** presents to client programs. If a C-function, structure, datatype,
14** or constant definition does not appear in this file, then it is
15** not a published API of SQLite, is subject to change without
16** notice, and should not be referenced by programs that use SQLite.
17**
18** Some of the definitions that are in this file are marked as
19** "experimental". Experimental interfaces are normally new
20** features recently added to SQLite. We do not anticipate changes
21** to experimental interfaces but reserve the right to make minor changes
22** if experience from use "in the wild" suggest such changes are prudent.
23**
24** The official C-language API documentation for SQLite is derived
25** from comments in this file. This file is the authoritative source
26** on how SQLite interfaces are supposed to operate.
27**
28** The name of this file under configuration management is "sqlite.h.in".
29** The makefile makes some minor changes to this file (such as inserting
30** the version number) and changes its name to "sqlite3.h" as
31** part of the build process.
32*/
33#ifndef SQLITE3_H
34#define SQLITE3_H
35#include <stdarg.h> /* Needed for the definition of va_list */
36
37/*
38** Make sure we can call this stuff from C++.
39*/
40#ifdef __cplusplus
41extern "C" {
42#endif
43
44
45/*
46** Facilitate override of interface linkage and calling conventions.
47** Be aware that these macros may not be used within this particular
48** translation of the amalgamation and its associated header file.
49**
50** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51** compiler that the target identifier should have external linkage.
52**
53** The SQLITE_CDECL macro is used to set the calling convention for
54** public functions that accept a variable number of arguments.
55**
56** The SQLITE_APICALL macro is used to set the calling convention for
57** public functions that accept a fixed number of arguments.
58**
59** The SQLITE_STDCALL macro is no longer used and is now deprecated.
60**
61** The SQLITE_CALLBACK macro is used to set the calling convention for
62** function pointers.
63**
64** The SQLITE_SYSAPI macro is used to set the calling convention for
65** functions provided by the operating system.
66**
67** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68** SQLITE_SYSAPI macros are used only when building for environments
69** that require non-default calling conventions.
70*/
71#ifndef SQLITE_EXTERN
72# define SQLITE_EXTERN extern
73#endif
74#ifndef SQLITE_API
75# define SQLITE_API
76#endif
77#ifndef SQLITE_CDECL
78# define SQLITE_CDECL
79#endif
80#ifndef SQLITE_APICALL
81# define SQLITE_APICALL
82#endif
83#ifndef SQLITE_STDCALL
84# define SQLITE_STDCALL SQLITE_APICALL
85#endif
86#ifndef SQLITE_CALLBACK
87# define SQLITE_CALLBACK
88#endif
89#ifndef SQLITE_SYSAPI
90# define SQLITE_SYSAPI
91#endif
92
93/*
94** These no-op macros are used in front of interfaces to mark those
95** interfaces as either deprecated or experimental. New applications
96** should not use deprecated interfaces - they are supported for backwards
97** compatibility only. Application writers should be aware that
98** experimental interfaces are subject to change in point releases.
99**
100** These macros used to resolve to various kinds of compiler magic that
101** would generate warning messages when they were used. But that
102** compiler magic ended up generating such a flurry of bug reports
103** that we have taken it all out and gone back to using simple
104** noop macros.
105*/
106#define SQLITE_DEPRECATED
107#define SQLITE_EXPERIMENTAL
108
109/*
110** Ensure these symbols were not defined by some previous header file.
111*/
112#ifdef SQLITE_VERSION
113# undef SQLITE_VERSION
114#endif
115#ifdef SQLITE_VERSION_NUMBER
116# undef SQLITE_VERSION_NUMBER
117#endif
118
119/*
120** CAPI3REF: Compile-Time Library Version Numbers
121**
122** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123** evaluates to a string literal that is the SQLite version in the
124** format "X.Y.Z" where X is the major version number (always 3 for
125** SQLite3) and Y is the minor version number and Z is the release number.)^
126** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128** numbers used in [SQLITE_VERSION].)^
129** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130** be larger than the release from which it is derived. Either Y will
131** be held constant and Z will be incremented or else Y will be incremented
132** and Z will be reset to zero.
133**
134** Since [version 3.6.18] ([dateof:3.6.18]),
135** SQLite source code has been stored in the
136** <a href="http://www.fossil-scm.org/">Fossil configuration management
137** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138** a string which identifies a particular check-in of SQLite
139** within its configuration management system. ^The SQLITE_SOURCE_ID
140** string contains the date and time of the check-in (UTC) and a SHA1
141** or SHA3-256 hash of the entire source tree. If the source code has
142** been edited in any way since it was last checked in, then the last
143** four hexadecimal digits of the hash may be modified.
144**
145** See also: [sqlite3_libversion()],
146** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147** [sqlite_version()] and [sqlite_source_id()].
148*/
149#define SQLITE_VERSION "3.39.2"
150#define SQLITE_VERSION_NUMBER 3039002
151#define SQLITE_SOURCE_ID "2022-07-21 15:24:47 698edb77537b67c41adc68f9b892db56bcf9a55e00371a61420f3ddd668e6603"
152
153/*
154** CAPI3REF: Run-Time Library Version Numbers
155** KEYWORDS: sqlite3_version sqlite3_sourceid
156**
157** These interfaces provide the same information as the [SQLITE_VERSION],
158** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
159** but are associated with the library instead of the header file. ^(Cautious
160** programmers might include assert() statements in their application to
161** verify that values returned by these interfaces match the macros in
162** the header, and thus ensure that the application is
163** compiled with matching library and header files.
164**
165** <blockquote><pre>
166** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
167** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
168** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
169** </pre></blockquote>)^
170**
171** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
172** macro. ^The sqlite3_libversion() function returns a pointer to the
173** to the sqlite3_version[] string constant. The sqlite3_libversion()
174** function is provided for use in DLLs since DLL users usually do not have
175** direct access to string constants within the DLL. ^The
176** sqlite3_libversion_number() function returns an integer equal to
177** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
178** a pointer to a string constant whose value is the same as the
179** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
180** using an edited copy of [the amalgamation], then the last four characters
181** of the hash might be different from [SQLITE_SOURCE_ID].)^
182**
183** See also: [sqlite_version()] and [sqlite_source_id()].
184*/
185SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
186SQLITE_API const char *sqlite3_libversion(void);
187SQLITE_API const char *sqlite3_sourceid(void);
188SQLITE_API int sqlite3_libversion_number(void);
189
190/*
191** CAPI3REF: Run-Time Library Compilation Options Diagnostics
192**
193** ^The sqlite3_compileoption_used() function returns 0 or 1
194** indicating whether the specified option was defined at
195** compile time. ^The SQLITE_ prefix may be omitted from the
196** option name passed to sqlite3_compileoption_used().
197**
198** ^The sqlite3_compileoption_get() function allows iterating
199** over the list of options that were defined at compile time by
200** returning the N-th compile time option string. ^If N is out of range,
201** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
202** prefix is omitted from any strings returned by
203** sqlite3_compileoption_get().
204**
205** ^Support for the diagnostic functions sqlite3_compileoption_used()
206** and sqlite3_compileoption_get() may be omitted by specifying the
207** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
208**
209** See also: SQL functions [sqlite_compileoption_used()] and
210** [sqlite_compileoption_get()] and the [compile_options pragma].
211*/
212#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
213SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
214SQLITE_API const char *sqlite3_compileoption_get(int N);
215#else
216# define sqlite3_compileoption_used(X) 0
217# define sqlite3_compileoption_get(X) ((void*)0)
218#endif
219
220/*
221** CAPI3REF: Test To See If The Library Is Threadsafe
222**
223** ^The sqlite3_threadsafe() function returns zero if and only if
224** SQLite was compiled with mutexing code omitted due to the
225** [SQLITE_THREADSAFE] compile-time option being set to 0.
226**
227** SQLite can be compiled with or without mutexes. When
228** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
229** are enabled and SQLite is threadsafe. When the
230** [SQLITE_THREADSAFE] macro is 0,
231** the mutexes are omitted. Without the mutexes, it is not safe
232** to use SQLite concurrently from more than one thread.
233**
234** Enabling mutexes incurs a measurable performance penalty.
235** So if speed is of utmost importance, it makes sense to disable
236** the mutexes. But for maximum safety, mutexes should be enabled.
237** ^The default behavior is for mutexes to be enabled.
238**
239** This interface can be used by an application to make sure that the
240** version of SQLite that it is linking against was compiled with
241** the desired setting of the [SQLITE_THREADSAFE] macro.
242**
243** This interface only reports on the compile-time mutex setting
244** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
245** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
246** can be fully or partially disabled using a call to [sqlite3_config()]
247** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
248** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
249** sqlite3_threadsafe() function shows only the compile-time setting of
250** thread safety, not any run-time changes to that setting made by
251** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
252** is unchanged by calls to sqlite3_config().)^
253**
254** See the [threading mode] documentation for additional information.
255*/
256SQLITE_API int sqlite3_threadsafe(void);
257
258/*
259** CAPI3REF: Database Connection Handle
260** KEYWORDS: {database connection} {database connections}
261**
262** Each open SQLite database is represented by a pointer to an instance of
263** the opaque structure named "sqlite3". It is useful to think of an sqlite3
264** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
265** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
266** and [sqlite3_close_v2()] are its destructors. There are many other
267** interfaces (such as
268** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
269** [sqlite3_busy_timeout()] to name but three) that are methods on an
270** sqlite3 object.
271*/
272typedef struct sqlite3 sqlite3;
273
274/*
275** CAPI3REF: 64-Bit Integer Types
276** KEYWORDS: sqlite_int64 sqlite_uint64
277**
278** Because there is no cross-platform way to specify 64-bit integer types
279** SQLite includes typedefs for 64-bit signed and unsigned integers.
280**
281** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
282** The sqlite_int64 and sqlite_uint64 types are supported for backwards
283** compatibility only.
284**
285** ^The sqlite3_int64 and sqlite_int64 types can store integer values
286** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
287** sqlite3_uint64 and sqlite_uint64 types can store integer values
288** between 0 and +18446744073709551615 inclusive.
289*/
290#ifdef SQLITE_INT64_TYPE
291 typedef SQLITE_INT64_TYPE sqlite_int64;
292# ifdef SQLITE_UINT64_TYPE
293 typedef SQLITE_UINT64_TYPE sqlite_uint64;
294# else
295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
296# endif
297#elif defined(_MSC_VER) || defined(__BORLANDC__)
298 typedef __int64 sqlite_int64;
299 typedef unsigned __int64 sqlite_uint64;
300#else
301 typedef long long int sqlite_int64;
302 typedef unsigned long long int sqlite_uint64;
303#endif
304typedef sqlite_int64 sqlite3_int64;
305typedef sqlite_uint64 sqlite3_uint64;
306
307/*
308** If compiling for a processor that lacks floating point support,
309** substitute integer for floating-point.
310*/
311#ifdef SQLITE_OMIT_FLOATING_POINT
312# define double sqlite3_int64
313#endif
314
315/*
316** CAPI3REF: Closing A Database Connection
317** DESTRUCTOR: sqlite3
318**
319** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
320** for the [sqlite3] object.
321** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
322** the [sqlite3] object is successfully destroyed and all associated
323** resources are deallocated.
324**
325** Ideally, applications should [sqlite3_finalize | finalize] all
326** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
327** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
328** with the [sqlite3] object prior to attempting to close the object.
329** ^If the database connection is associated with unfinalized prepared
330** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
331** sqlite3_close() will leave the database connection open and return
332** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
333** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
334** it returns [SQLITE_OK] regardless, but instead of deallocating the database
335** connection immediately, it marks the database connection as an unusable
336** "zombie" and makes arrangements to automatically deallocate the database
337** connection after all prepared statements are finalized, all BLOB handles
338** are closed, and all backups have finished. The sqlite3_close_v2() interface
339** is intended for use with host languages that are garbage collected, and
340** where the order in which destructors are called is arbitrary.
341**
342** ^If an [sqlite3] object is destroyed while a transaction is open,
343** the transaction is automatically rolled back.
344**
345** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
346** must be either a NULL
347** pointer or an [sqlite3] object pointer obtained
348** from [sqlite3_open()], [sqlite3_open16()], or
349** [sqlite3_open_v2()], and not previously closed.
350** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
351** argument is a harmless no-op.
352*/
353SQLITE_API int sqlite3_close(sqlite3*);
354SQLITE_API int sqlite3_close_v2(sqlite3*);
355
356/*
357** The type for a callback function.
358** This is legacy and deprecated. It is included for historical
359** compatibility and is not documented.
360*/
361typedef int (*sqlite3_callback)(void*,int,char**, char**);
362
363/*
364** CAPI3REF: One-Step Query Execution Interface
365** METHOD: sqlite3
366**
367** The sqlite3_exec() interface is a convenience wrapper around
368** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
369** that allows an application to run multiple statements of SQL
370** without having to use a lot of C code.
371**
372** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
373** semicolon-separate SQL statements passed into its 2nd argument,
374** in the context of the [database connection] passed in as its 1st
375** argument. ^If the callback function of the 3rd argument to
376** sqlite3_exec() is not NULL, then it is invoked for each result row
377** coming out of the evaluated SQL statements. ^The 4th argument to
378** sqlite3_exec() is relayed through to the 1st argument of each
379** callback invocation. ^If the callback pointer to sqlite3_exec()
380** is NULL, then no callback is ever invoked and result rows are
381** ignored.
382**
383** ^If an error occurs while evaluating the SQL statements passed into
384** sqlite3_exec(), then execution of the current statement stops and
385** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
386** is not NULL then any error message is written into memory obtained
387** from [sqlite3_malloc()] and passed back through the 5th parameter.
388** To avoid memory leaks, the application should invoke [sqlite3_free()]
389** on error message strings returned through the 5th parameter of
390** sqlite3_exec() after the error message string is no longer needed.
391** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
392** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
393** NULL before returning.
394**
395** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
396** routine returns SQLITE_ABORT without invoking the callback again and
397** without running any subsequent SQL statements.
398**
399** ^The 2nd argument to the sqlite3_exec() callback function is the
400** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
401** callback is an array of pointers to strings obtained as if from
402** [sqlite3_column_text()], one for each column. ^If an element of a
403** result row is NULL then the corresponding string pointer for the
404** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
405** sqlite3_exec() callback is an array of pointers to strings where each
406** entry represents the name of corresponding result column as obtained
407** from [sqlite3_column_name()].
408**
409** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
410** to an empty string, or a pointer that contains only whitespace and/or
411** SQL comments, then no SQL statements are evaluated and the database
412** is not changed.
413**
414** Restrictions:
415**
416** <ul>
417** <li> The application must ensure that the 1st parameter to sqlite3_exec()
418** is a valid and open [database connection].
419** <li> The application must not close the [database connection] specified by
420** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
421** <li> The application must not modify the SQL statement text passed into
422** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
423** </ul>
424*/
425SQLITE_API int sqlite3_exec(
426 sqlite3*, /* An open database */
427 const char *sql, /* SQL to be evaluated */
428 int (*callback)(void*,int,char**,char**), /* Callback function */
429 void *, /* 1st argument to callback */
430 char **errmsg /* Error msg written here */
431);
432
433/*
434** CAPI3REF: Result Codes
435** KEYWORDS: {result code definitions}
436**
437** Many SQLite functions return an integer result code from the set shown
438** here in order to indicate success or failure.
439**
440** New error codes may be added in future versions of SQLite.
441**
442** See also: [extended result code definitions]
443*/
444#define SQLITE_OK 0 /* Successful result */
445/* beginning-of-error-codes */
446#define SQLITE_ERROR 1 /* Generic error */
447#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
448#define SQLITE_PERM 3 /* Access permission denied */
449#define SQLITE_ABORT 4 /* Callback routine requested an abort */
450#define SQLITE_BUSY 5 /* The database file is locked */
451#define SQLITE_LOCKED 6 /* A table in the database is locked */
452#define SQLITE_NOMEM 7 /* A malloc() failed */
453#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
454#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
455#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
456#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
457#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
458#define SQLITE_FULL 13 /* Insertion failed because database is full */
459#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
460#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
461#define SQLITE_EMPTY 16 /* Internal use only */
462#define SQLITE_SCHEMA 17 /* The database schema changed */
463#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
464#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
465#define SQLITE_MISMATCH 20 /* Data type mismatch */
466#define SQLITE_MISUSE 21 /* Library used incorrectly */
467#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
468#define SQLITE_AUTH 23 /* Authorization denied */
469#define SQLITE_FORMAT 24 /* Not used */
470#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
471#define SQLITE_NOTADB 26 /* File opened that is not a database file */
472#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
473#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
474#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
475#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
476/* end-of-error-codes */
477
478/*
479** CAPI3REF: Extended Result Codes
480** KEYWORDS: {extended result code definitions}
481**
482** In its default configuration, SQLite API routines return one of 30 integer
483** [result codes]. However, experience has shown that many of
484** these result codes are too coarse-grained. They do not provide as
485** much information about problems as programmers might like. In an effort to
486** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
487** and later) include
488** support for additional result codes that provide more detailed information
489** about errors. These [extended result codes] are enabled or disabled
490** on a per database connection basis using the
491** [sqlite3_extended_result_codes()] API. Or, the extended code for
492** the most recent error can be obtained using
493** [sqlite3_extended_errcode()].
494*/
495#define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
496#define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
497#define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
498#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
499#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
500#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
501#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
502#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
503#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
504#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
505#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
506#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
507#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
508#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
509#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
510#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
511#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
512#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
513#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
514#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
515#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
516#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
517#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
518#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
519#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
520#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
521#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
522#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
523#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
524#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
525#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
526#define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
527#define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
528#define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
529#define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
530#define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
531#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
532#define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
533#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
534#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
535#define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
536#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
537#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
538#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
539#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
540#define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
541#define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
542#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
543#define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
544#define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
545#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
546#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
547#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
548#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
549#define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
550#define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
551#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
552#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
553#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
554#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
555#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
556#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
557#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
558#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
559#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
560#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
561#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
562#define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
563#define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
564#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
565#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
566#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
567#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
568#define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
569#define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
570
571/*
572** CAPI3REF: Flags For File Open Operations
573**
574** These bit values are intended for use in the
575** 3rd parameter to the [sqlite3_open_v2()] interface and
576** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
577**
578** Only those flags marked as "Ok for sqlite3_open_v2()" may be
579** used as the third argument to the [sqlite3_open_v2()] interface.
580** The other flags have historically been ignored by sqlite3_open_v2(),
581** though future versions of SQLite might change so that an error is
582** raised if any of the disallowed bits are passed into sqlite3_open_v2().
583** Applications should not depend on the historical behavior.
584**
585** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
586** [sqlite3_open_v2()] does *not* cause the underlying database file
587** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
588** [sqlite3_open_v2()] has historically be a no-op and might become an
589** error in future versions of SQLite.
590*/
591#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
592#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
593#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
594#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
595#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
596#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
597#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
598#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
599#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
600#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
601#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
602#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
603#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
604#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
605#define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
606#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
607#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
608#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
609#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
610#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
611#define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
612#define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
613
614/* Reserved: 0x00F00000 */
615/* Legacy compatibility: */
616#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
617
618
619/*
620** CAPI3REF: Device Characteristics
621**
622** The xDeviceCharacteristics method of the [sqlite3_io_methods]
623** object returns an integer which is a vector of these
624** bit values expressing I/O characteristics of the mass storage
625** device that holds the file that the [sqlite3_io_methods]
626** refers to.
627**
628** The SQLITE_IOCAP_ATOMIC property means that all writes of
629** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
630** mean that writes of blocks that are nnn bytes in size and
631** are aligned to an address which is an integer multiple of
632** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
633** that when data is appended to a file, the data is appended
634** first then the size of the file is extended, never the other
635** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
636** information is written to disk in the same order as calls
637** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
638** after reboot following a crash or power loss, the only bytes in a
639** file that were written at the application level might have changed
640** and that adjacent bytes, even bytes within the same sector are
641** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
642** flag indicates that a file cannot be deleted when open. The
643** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
644** read-only media and cannot be changed even by processes with
645** elevated privileges.
646**
647** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
648** filesystem supports doing multiple write operations atomically when those
649** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
650** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
651*/
652#define SQLITE_IOCAP_ATOMIC 0x00000001
653#define SQLITE_IOCAP_ATOMIC512 0x00000002
654#define SQLITE_IOCAP_ATOMIC1K 0x00000004
655#define SQLITE_IOCAP_ATOMIC2K 0x00000008
656#define SQLITE_IOCAP_ATOMIC4K 0x00000010
657#define SQLITE_IOCAP_ATOMIC8K 0x00000020
658#define SQLITE_IOCAP_ATOMIC16K 0x00000040
659#define SQLITE_IOCAP_ATOMIC32K 0x00000080
660#define SQLITE_IOCAP_ATOMIC64K 0x00000100
661#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
662#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
663#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
664#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
665#define SQLITE_IOCAP_IMMUTABLE 0x00002000
666#define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
667
668/*
669** CAPI3REF: File Locking Levels
670**
671** SQLite uses one of these integer values as the second
672** argument to calls it makes to the xLock() and xUnlock() methods
673** of an [sqlite3_io_methods] object.
674*/
675#define SQLITE_LOCK_NONE 0
676#define SQLITE_LOCK_SHARED 1
677#define SQLITE_LOCK_RESERVED 2
678#define SQLITE_LOCK_PENDING 3
679#define SQLITE_LOCK_EXCLUSIVE 4
680
681/*
682** CAPI3REF: Synchronization Type Flags
683**
684** When SQLite invokes the xSync() method of an
685** [sqlite3_io_methods] object it uses a combination of
686** these integer values as the second argument.
687**
688** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
689** sync operation only needs to flush data to mass storage. Inode
690** information need not be flushed. If the lower four bits of the flag
691** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
692** If the lower four bits equal SQLITE_SYNC_FULL, that means
693** to use Mac OS X style fullsync instead of fsync().
694**
695** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
696** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
697** settings. The [synchronous pragma] determines when calls to the
698** xSync VFS method occur and applies uniformly across all platforms.
699** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
700** energetic or rigorous or forceful the sync operations are and
701** only make a difference on Mac OSX for the default SQLite code.
702** (Third-party VFS implementations might also make the distinction
703** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
704** operating systems natively supported by SQLite, only Mac OSX
705** cares about the difference.)
706*/
707#define SQLITE_SYNC_NORMAL 0x00002
708#define SQLITE_SYNC_FULL 0x00003
709#define SQLITE_SYNC_DATAONLY 0x00010
710
711/*
712** CAPI3REF: OS Interface Open File Handle
713**
714** An [sqlite3_file] object represents an open file in the
715** [sqlite3_vfs | OS interface layer]. Individual OS interface
716** implementations will
717** want to subclass this object by appending additional fields
718** for their own use. The pMethods entry is a pointer to an
719** [sqlite3_io_methods] object that defines methods for performing
720** I/O operations on the open file.
721*/
722typedef struct sqlite3_file sqlite3_file;
723struct sqlite3_file {
724 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
725};
726
727/*
728** CAPI3REF: OS Interface File Virtual Methods Object
729**
730** Every file opened by the [sqlite3_vfs.xOpen] method populates an
731** [sqlite3_file] object (or, more commonly, a subclass of the
732** [sqlite3_file] object) with a pointer to an instance of this object.
733** This object defines the methods used to perform various operations
734** against the open file represented by the [sqlite3_file] object.
735**
736** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
737** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
738** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
739** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
740** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
741** to NULL.
742**
743** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
744** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
745** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
746** flag may be ORed in to indicate that only the data of the file
747** and not its inode needs to be synced.
748**
749** The integer values to xLock() and xUnlock() are one of
750** <ul>
751** <li> [SQLITE_LOCK_NONE],
752** <li> [SQLITE_LOCK_SHARED],
753** <li> [SQLITE_LOCK_RESERVED],
754** <li> [SQLITE_LOCK_PENDING], or
755** <li> [SQLITE_LOCK_EXCLUSIVE].
756** </ul>
757** xLock() increases the lock. xUnlock() decreases the lock.
758** The xCheckReservedLock() method checks whether any database connection,
759** either in this process or in some other process, is holding a RESERVED,
760** PENDING, or EXCLUSIVE lock on the file. It returns true
761** if such a lock exists and false otherwise.
762**
763** The xFileControl() method is a generic interface that allows custom
764** VFS implementations to directly control an open file using the
765** [sqlite3_file_control()] interface. The second "op" argument is an
766** integer opcode. The third argument is a generic pointer intended to
767** point to a structure that may contain arguments or space in which to
768** write return values. Potential uses for xFileControl() might be
769** functions to enable blocking locks with timeouts, to change the
770** locking strategy (for example to use dot-file locks), to inquire
771** about the status of a lock, or to break stale locks. The SQLite
772** core reserves all opcodes less than 100 for its own use.
773** A [file control opcodes | list of opcodes] less than 100 is available.
774** Applications that define a custom xFileControl method should use opcodes
775** greater than 100 to avoid conflicts. VFS implementations should
776** return [SQLITE_NOTFOUND] for file control opcodes that they do not
777** recognize.
778**
779** The xSectorSize() method returns the sector size of the
780** device that underlies the file. The sector size is the
781** minimum write that can be performed without disturbing
782** other bytes in the file. The xDeviceCharacteristics()
783** method returns a bit vector describing behaviors of the
784** underlying device:
785**
786** <ul>
787** <li> [SQLITE_IOCAP_ATOMIC]
788** <li> [SQLITE_IOCAP_ATOMIC512]
789** <li> [SQLITE_IOCAP_ATOMIC1K]
790** <li> [SQLITE_IOCAP_ATOMIC2K]
791** <li> [SQLITE_IOCAP_ATOMIC4K]
792** <li> [SQLITE_IOCAP_ATOMIC8K]
793** <li> [SQLITE_IOCAP_ATOMIC16K]
794** <li> [SQLITE_IOCAP_ATOMIC32K]
795** <li> [SQLITE_IOCAP_ATOMIC64K]
796** <li> [SQLITE_IOCAP_SAFE_APPEND]
797** <li> [SQLITE_IOCAP_SEQUENTIAL]
798** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
799** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
800** <li> [SQLITE_IOCAP_IMMUTABLE]
801** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
802** </ul>
803**
804** The SQLITE_IOCAP_ATOMIC property means that all writes of
805** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
806** mean that writes of blocks that are nnn bytes in size and
807** are aligned to an address which is an integer multiple of
808** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
809** that when data is appended to a file, the data is appended
810** first then the size of the file is extended, never the other
811** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
812** information is written to disk in the same order as calls
813** to xWrite().
814**
815** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
816** in the unread portions of the buffer with zeros. A VFS that
817** fails to zero-fill short reads might seem to work. However,
818** failure to zero-fill short reads will eventually lead to
819** database corruption.
820*/
821typedef struct sqlite3_io_methods sqlite3_io_methods;
822struct sqlite3_io_methods {
823 int iVersion;
824 int (*xClose)(sqlite3_file*);
825 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
826 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
827 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
828 int (*xSync)(sqlite3_file*, int flags);
829 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
830 int (*xLock)(sqlite3_file*, int);
831 int (*xUnlock)(sqlite3_file*, int);
832 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
833 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
834 int (*xSectorSize)(sqlite3_file*);
835 int (*xDeviceCharacteristics)(sqlite3_file*);
836 /* Methods above are valid for version 1 */
837 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
838 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
839 void (*xShmBarrier)(sqlite3_file*);
840 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
841 /* Methods above are valid for version 2 */
842 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
843 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
844 /* Methods above are valid for version 3 */
845 /* Additional methods may be added in future releases */
846};
847
848/*
849** CAPI3REF: Standard File Control Opcodes
850** KEYWORDS: {file control opcodes} {file control opcode}
851**
852** These integer constants are opcodes for the xFileControl method
853** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
854** interface.
855**
856** <ul>
857** <li>[[SQLITE_FCNTL_LOCKSTATE]]
858** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
859** opcode causes the xFileControl method to write the current state of
860** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
861** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
862** into an integer that the pArg argument points to. This capability
863** is used during testing and is only available when the SQLITE_TEST
864** compile-time option is used.
865**
866** <li>[[SQLITE_FCNTL_SIZE_HINT]]
867** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
868** layer a hint of how large the database file will grow to be during the
869** current transaction. This hint is not guaranteed to be accurate but it
870** is often close. The underlying VFS might choose to preallocate database
871** file space based on this hint in order to help writes to the database
872** file run faster.
873**
874** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
875** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
876** implements [sqlite3_deserialize()] to set an upper bound on the size
877** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
878** If the integer pointed to is negative, then it is filled in with the
879** current limit. Otherwise the limit is set to the larger of the value
880** of the integer pointed to and the current database size. The integer
881** pointed to is set to the new limit.
882**
883** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
884** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
885** extends and truncates the database file in chunks of a size specified
886** by the user. The fourth argument to [sqlite3_file_control()] should
887** point to an integer (type int) containing the new chunk-size to use
888** for the nominated database. Allocating database file space in large
889** chunks (say 1MB at a time), may reduce file-system fragmentation and
890** improve performance on some systems.
891**
892** <li>[[SQLITE_FCNTL_FILE_POINTER]]
893** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
894** to the [sqlite3_file] object associated with a particular database
895** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
896**
897** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
898** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
899** to the [sqlite3_file] object associated with the journal file (either
900** the [rollback journal] or the [write-ahead log]) for a particular database
901** connection. See also [SQLITE_FCNTL_FILE_POINTER].
902**
903** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
904** No longer in use.
905**
906** <li>[[SQLITE_FCNTL_SYNC]]
907** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
908** sent to the VFS immediately before the xSync method is invoked on a
909** database file descriptor. Or, if the xSync method is not invoked
910** because the user has configured SQLite with
911** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
912** of the xSync method. In most cases, the pointer argument passed with
913** this file-control is NULL. However, if the database file is being synced
914** as part of a multi-database commit, the argument points to a nul-terminated
915** string containing the transactions super-journal file name. VFSes that
916** do not need this signal should silently ignore this opcode. Applications
917** should not call [sqlite3_file_control()] with this opcode as doing so may
918** disrupt the operation of the specialized VFSes that do require it.
919**
920** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
921** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
922** and sent to the VFS after a transaction has been committed immediately
923** but before the database is unlocked. VFSes that do not need this signal
924** should silently ignore this opcode. Applications should not call
925** [sqlite3_file_control()] with this opcode as doing so may disrupt the
926** operation of the specialized VFSes that do require it.
927**
928** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
929** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
930** retry counts and intervals for certain disk I/O operations for the
931** windows [VFS] in order to provide robustness in the presence of
932** anti-virus programs. By default, the windows VFS will retry file read,
933** file write, and file delete operations up to 10 times, with a delay
934** of 25 milliseconds before the first retry and with the delay increasing
935** by an additional 25 milliseconds with each subsequent retry. This
936** opcode allows these two values (10 retries and 25 milliseconds of delay)
937** to be adjusted. The values are changed for all database connections
938** within the same process. The argument is a pointer to an array of two
939** integers where the first integer is the new retry count and the second
940** integer is the delay. If either integer is negative, then the setting
941** is not changed but instead the prior value of that setting is written
942** into the array entry, allowing the current retry settings to be
943** interrogated. The zDbName parameter is ignored.
944**
945** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
946** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
947** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
948** write ahead log ([WAL file]) and shared memory
949** files used for transaction control
950** are automatically deleted when the latest connection to the database
951** closes. Setting persistent WAL mode causes those files to persist after
952** close. Persisting the files is useful when other processes that do not
953** have write permission on the directory containing the database file want
954** to read the database file, as the WAL and shared memory files must exist
955** in order for the database to be readable. The fourth parameter to
956** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
957** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
958** WAL mode. If the integer is -1, then it is overwritten with the current
959** WAL persistence setting.
960**
961** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
962** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
963** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
964** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
965** xDeviceCharacteristics methods. The fourth parameter to
966** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
967** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
968** mode. If the integer is -1, then it is overwritten with the current
969** zero-damage mode setting.
970**
971** <li>[[SQLITE_FCNTL_OVERWRITE]]
972** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
973** a write transaction to indicate that, unless it is rolled back for some
974** reason, the entire database file will be overwritten by the current
975** transaction. This is used by VACUUM operations.
976**
977** <li>[[SQLITE_FCNTL_VFSNAME]]
978** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
979** all [VFSes] in the VFS stack. The names are of all VFS shims and the
980** final bottom-level VFS are written into memory obtained from
981** [sqlite3_malloc()] and the result is stored in the char* variable
982** that the fourth parameter of [sqlite3_file_control()] points to.
983** The caller is responsible for freeing the memory when done. As with
984** all file-control actions, there is no guarantee that this will actually
985** do anything. Callers should initialize the char* variable to a NULL
986** pointer in case this file-control is not implemented. This file-control
987** is intended for diagnostic use only.
988**
989** <li>[[SQLITE_FCNTL_VFS_POINTER]]
990** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
991** [VFSes] currently in use. ^(The argument X in
992** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
993** of type "[sqlite3_vfs] **". This opcodes will set *X
994** to a pointer to the top-level VFS.)^
995** ^When there are multiple VFS shims in the stack, this opcode finds the
996** upper-most shim only.
997**
998** <li>[[SQLITE_FCNTL_PRAGMA]]
999** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1000** file control is sent to the open [sqlite3_file] object corresponding
1001** to the database file to which the pragma statement refers. ^The argument
1002** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1003** pointers to strings (char**) in which the second element of the array
1004** is the name of the pragma and the third element is the argument to the
1005** pragma or NULL if the pragma has no argument. ^The handler for an
1006** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1007** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1008** or the equivalent and that string will become the result of the pragma or
1009** the error message if the pragma fails. ^If the
1010** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1011** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1012** file control returns [SQLITE_OK], then the parser assumes that the
1013** VFS has handled the PRAGMA itself and the parser generates a no-op
1014** prepared statement if result string is NULL, or that returns a copy
1015** of the result string if the string is non-NULL.
1016** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1017** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1018** that the VFS encountered an error while handling the [PRAGMA] and the
1019** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1020** file control occurs at the beginning of pragma statement analysis and so
1021** it is able to override built-in [PRAGMA] statements.
1022**
1023** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1024** ^The [SQLITE_FCNTL_BUSYHANDLER]
1025** file-control may be invoked by SQLite on the database file handle
1026** shortly after it is opened in order to provide a custom VFS with access
1027** to the connection's busy-handler callback. The argument is of type (void**)
1028** - an array of two (void *) values. The first (void *) actually points
1029** to a function of type (int (*)(void *)). In order to invoke the connection's
1030** busy-handler, this function should be invoked with the second (void *) in
1031** the array as the only argument. If it returns non-zero, then the operation
1032** should be retried. If it returns zero, the custom VFS should abandon the
1033** current operation.
1034**
1035** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1036** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1037** to have SQLite generate a
1038** temporary filename using the same algorithm that is followed to generate
1039** temporary filenames for TEMP tables and other internal uses. The
1040** argument should be a char** which will be filled with the filename
1041** written into memory obtained from [sqlite3_malloc()]. The caller should
1042** invoke [sqlite3_free()] on the result to avoid a memory leak.
1043**
1044** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1045** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1046** maximum number of bytes that will be used for memory-mapped I/O.
1047** The argument is a pointer to a value of type sqlite3_int64 that
1048** is an advisory maximum number of bytes in the file to memory map. The
1049** pointer is overwritten with the old value. The limit is not changed if
1050** the value originally pointed to is negative, and so the current limit
1051** can be queried by passing in a pointer to a negative number. This
1052** file-control is used internally to implement [PRAGMA mmap_size].
1053**
1054** <li>[[SQLITE_FCNTL_TRACE]]
1055** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1056** to the VFS about what the higher layers of the SQLite stack are doing.
1057** This file control is used by some VFS activity tracing [shims].
1058** The argument is a zero-terminated string. Higher layers in the
1059** SQLite stack may generate instances of this file control if
1060** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1061**
1062** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1063** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1064** pointer to an integer and it writes a boolean into that integer depending
1065** on whether or not the file has been renamed, moved, or deleted since it
1066** was first opened.
1067**
1068** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1069** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1070** underlying native file handle associated with a file handle. This file
1071** control interprets its argument as a pointer to a native file handle and
1072** writes the resulting value there.
1073**
1074** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1075** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1076** opcode causes the xFileControl method to swap the file handle with the one
1077** pointed to by the pArg argument. This capability is used during testing
1078** and only needs to be supported when SQLITE_TEST is defined.
1079**
1080** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1081** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1082** be advantageous to block on the next WAL lock if the lock is not immediately
1083** available. The WAL subsystem issues this signal during rare
1084** circumstances in order to fix a problem with priority inversion.
1085** Applications should <em>not</em> use this file-control.
1086**
1087** <li>[[SQLITE_FCNTL_ZIPVFS]]
1088** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1089** VFS should return SQLITE_NOTFOUND for this opcode.
1090**
1091** <li>[[SQLITE_FCNTL_RBU]]
1092** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1093** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1094** this opcode.
1095**
1096** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1097** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1098** the file descriptor is placed in "batch write mode", which
1099** means all subsequent write operations will be deferred and done
1100** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1101** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1102** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1103** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1104** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1105** no VFS interface calls on the same [sqlite3_file] file descriptor
1106** except for calls to the xWrite method and the xFileControl method
1107** with [SQLITE_FCNTL_SIZE_HINT].
1108**
1109** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1110** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1111** operations since the previous successful call to
1112** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1113** This file control returns [SQLITE_OK] if and only if the writes were
1114** all performed successfully and have been committed to persistent storage.
1115** ^Regardless of whether or not it is successful, this file control takes
1116** the file descriptor out of batch write mode so that all subsequent
1117** write operations are independent.
1118** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1119** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1120**
1121** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1122** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1123** operations since the previous successful call to
1124** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1125** ^This file control takes the file descriptor out of batch write mode
1126** so that all subsequent write operations are independent.
1127** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1128** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1129**
1130** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1131** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1132** to block for up to M milliseconds before failing when attempting to
1133** obtain a file lock using the xLock or xShmLock methods of the VFS.
1134** The parameter is a pointer to a 32-bit signed integer that contains
1135** the value that M is to be set to. Before returning, the 32-bit signed
1136** integer is overwritten with the previous value of M.
1137**
1138** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1139** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1140** a database file. The argument is a pointer to a 32-bit unsigned integer.
1141** The "data version" for the pager is written into the pointer. The
1142** "data version" changes whenever any change occurs to the corresponding
1143** database file, either through SQL statements on the same database
1144** connection or through transactions committed by separate database
1145** connections possibly in other processes. The [sqlite3_total_changes()]
1146** interface can be used to find if any database on the connection has changed,
1147** but that interface responds to changes on TEMP as well as MAIN and does
1148** not provide a mechanism to detect changes to MAIN only. Also, the
1149** [sqlite3_total_changes()] interface responds to internal changes only and
1150** omits changes made by other database connections. The
1151** [PRAGMA data_version] command provides a mechanism to detect changes to
1152** a single attached database that occur due to other database connections,
1153** but omits changes implemented by the database connection on which it is
1154** called. This file control is the only mechanism to detect changes that
1155** happen either internally or externally and that are associated with
1156** a particular attached database.
1157**
1158** <li>[[SQLITE_FCNTL_CKPT_START]]
1159** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1160** in wal mode before the client starts to copy pages from the wal
1161** file to the database file.
1162**
1163** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1164** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1165** in wal mode after the client has finished copying pages from the wal
1166** file to the database file, but before the *-shm file is updated to
1167** record the fact that the pages have been checkpointed.
1168** </ul>
1169**
1170** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1171** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1172** whether or not there is a database client in another process with a wal-mode
1173** transaction open on the database or not. It is only available on unix.The
1174** (void*) argument passed with this file-control should be a pointer to a
1175** value of type (int). The integer value is set to 1 if the database is a wal
1176** mode database and there exists at least one client in another process that
1177** currently has an SQL transaction open on the database. It is set to 0 if
1178** the database is not a wal-mode db, or if there is no such connection in any
1179** other process. This opcode cannot be used to detect transactions opened
1180** by clients within the current process, only within other processes.
1181** </ul>
1182**
1183** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1184** Used by the cksmvfs VFS module only.
1185** </ul>
1186*/
1187#define SQLITE_FCNTL_LOCKSTATE 1
1188#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1189#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1190#define SQLITE_FCNTL_LAST_ERRNO 4
1191#define SQLITE_FCNTL_SIZE_HINT 5
1192#define SQLITE_FCNTL_CHUNK_SIZE 6
1193#define SQLITE_FCNTL_FILE_POINTER 7
1194#define SQLITE_FCNTL_SYNC_OMITTED 8
1195#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1196#define SQLITE_FCNTL_PERSIST_WAL 10
1197#define SQLITE_FCNTL_OVERWRITE 11
1198#define SQLITE_FCNTL_VFSNAME 12
1199#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1200#define SQLITE_FCNTL_PRAGMA 14
1201#define SQLITE_FCNTL_BUSYHANDLER 15
1202#define SQLITE_FCNTL_TEMPFILENAME 16
1203#define SQLITE_FCNTL_MMAP_SIZE 18
1204#define SQLITE_FCNTL_TRACE 19
1205#define SQLITE_FCNTL_HAS_MOVED 20
1206#define SQLITE_FCNTL_SYNC 21
1207#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1208#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1209#define SQLITE_FCNTL_WAL_BLOCK 24
1210#define SQLITE_FCNTL_ZIPVFS 25
1211#define SQLITE_FCNTL_RBU 26
1212#define SQLITE_FCNTL_VFS_POINTER 27
1213#define SQLITE_FCNTL_JOURNAL_POINTER 28
1214#define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1215#define SQLITE_FCNTL_PDB 30
1216#define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1217#define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1218#define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1219#define SQLITE_FCNTL_LOCK_TIMEOUT 34
1220#define SQLITE_FCNTL_DATA_VERSION 35
1221#define SQLITE_FCNTL_SIZE_LIMIT 36
1222#define SQLITE_FCNTL_CKPT_DONE 37
1223#define SQLITE_FCNTL_RESERVE_BYTES 38
1224#define SQLITE_FCNTL_CKPT_START 39
1225#define SQLITE_FCNTL_EXTERNAL_READER 40
1226#define SQLITE_FCNTL_CKSM_FILE 41
1227
1228/* deprecated names */
1229#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1230#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1231#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1232
1233
1234/*
1235** CAPI3REF: Mutex Handle
1236**
1237** The mutex module within SQLite defines [sqlite3_mutex] to be an
1238** abstract type for a mutex object. The SQLite core never looks
1239** at the internal representation of an [sqlite3_mutex]. It only
1240** deals with pointers to the [sqlite3_mutex] object.
1241**
1242** Mutexes are created using [sqlite3_mutex_alloc()].
1243*/
1244typedef struct sqlite3_mutex sqlite3_mutex;
1245
1246/*
1247** CAPI3REF: Loadable Extension Thunk
1248**
1249** A pointer to the opaque sqlite3_api_routines structure is passed as
1250** the third parameter to entry points of [loadable extensions]. This
1251** structure must be typedefed in order to work around compiler warnings
1252** on some platforms.
1253*/
1254typedef struct sqlite3_api_routines sqlite3_api_routines;
1255
1256/*
1257** CAPI3REF: OS Interface Object
1258**
1259** An instance of the sqlite3_vfs object defines the interface between
1260** the SQLite core and the underlying operating system. The "vfs"
1261** in the name of the object stands for "virtual file system". See
1262** the [VFS | VFS documentation] for further information.
1263**
1264** The VFS interface is sometimes extended by adding new methods onto
1265** the end. Each time such an extension occurs, the iVersion field
1266** is incremented. The iVersion value started out as 1 in
1267** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1268** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1269** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1270** may be appended to the sqlite3_vfs object and the iVersion value
1271** may increase again in future versions of SQLite.
1272** Note that due to an oversight, the structure
1273** of the sqlite3_vfs object changed in the transition from
1274** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1275** and yet the iVersion field was not increased.
1276**
1277** The szOsFile field is the size of the subclassed [sqlite3_file]
1278** structure used by this VFS. mxPathname is the maximum length of
1279** a pathname in this VFS.
1280**
1281** Registered sqlite3_vfs objects are kept on a linked list formed by
1282** the pNext pointer. The [sqlite3_vfs_register()]
1283** and [sqlite3_vfs_unregister()] interfaces manage this list
1284** in a thread-safe way. The [sqlite3_vfs_find()] interface
1285** searches the list. Neither the application code nor the VFS
1286** implementation should use the pNext pointer.
1287**
1288** The pNext field is the only field in the sqlite3_vfs
1289** structure that SQLite will ever modify. SQLite will only access
1290** or modify this field while holding a particular static mutex.
1291** The application should never modify anything within the sqlite3_vfs
1292** object once the object has been registered.
1293**
1294** The zName field holds the name of the VFS module. The name must
1295** be unique across all VFS modules.
1296**
1297** [[sqlite3_vfs.xOpen]]
1298** ^SQLite guarantees that the zFilename parameter to xOpen
1299** is either a NULL pointer or string obtained
1300** from xFullPathname() with an optional suffix added.
1301** ^If a suffix is added to the zFilename parameter, it will
1302** consist of a single "-" character followed by no more than
1303** 11 alphanumeric and/or "-" characters.
1304** ^SQLite further guarantees that
1305** the string will be valid and unchanged until xClose() is
1306** called. Because of the previous sentence,
1307** the [sqlite3_file] can safely store a pointer to the
1308** filename if it needs to remember the filename for some reason.
1309** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1310** must invent its own temporary name for the file. ^Whenever the
1311** xFilename parameter is NULL it will also be the case that the
1312** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1313**
1314** The flags argument to xOpen() includes all bits set in
1315** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1316** or [sqlite3_open16()] is used, then flags includes at least
1317** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1318** If xOpen() opens a file read-only then it sets *pOutFlags to
1319** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1320**
1321** ^(SQLite will also add one of the following flags to the xOpen()
1322** call, depending on the object being opened:
1323**
1324** <ul>
1325** <li> [SQLITE_OPEN_MAIN_DB]
1326** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1327** <li> [SQLITE_OPEN_TEMP_DB]
1328** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1329** <li> [SQLITE_OPEN_TRANSIENT_DB]
1330** <li> [SQLITE_OPEN_SUBJOURNAL]
1331** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1332** <li> [SQLITE_OPEN_WAL]
1333** </ul>)^
1334**
1335** The file I/O implementation can use the object type flags to
1336** change the way it deals with files. For example, an application
1337** that does not care about crash recovery or rollback might make
1338** the open of a journal file a no-op. Writes to this journal would
1339** also be no-ops, and any attempt to read the journal would return
1340** SQLITE_IOERR. Or the implementation might recognize that a database
1341** file will be doing page-aligned sector reads and writes in a random
1342** order and set up its I/O subsystem accordingly.
1343**
1344** SQLite might also add one of the following flags to the xOpen method:
1345**
1346** <ul>
1347** <li> [SQLITE_OPEN_DELETEONCLOSE]
1348** <li> [SQLITE_OPEN_EXCLUSIVE]
1349** </ul>
1350**
1351** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1352** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1353** will be set for TEMP databases and their journals, transient
1354** databases, and subjournals.
1355**
1356** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1357** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1358** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1359** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1360** SQLITE_OPEN_CREATE, is used to indicate that file should always
1361** be created, and that it is an error if it already exists.
1362** It is <i>not</i> used to indicate the file should be opened
1363** for exclusive access.
1364**
1365** ^At least szOsFile bytes of memory are allocated by SQLite
1366** to hold the [sqlite3_file] structure passed as the third
1367** argument to xOpen. The xOpen method does not have to
1368** allocate the structure; it should just fill it in. Note that
1369** the xOpen method must set the sqlite3_file.pMethods to either
1370** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1371** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1372** element will be valid after xOpen returns regardless of the success
1373** or failure of the xOpen call.
1374**
1375** [[sqlite3_vfs.xAccess]]
1376** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1377** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1378** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1379** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1380** flag is never actually used and is not implemented in the built-in
1381** VFSes of SQLite. The file is named by the second argument and can be a
1382** directory. The xAccess method returns [SQLITE_OK] on success or some
1383** non-zero error code if there is an I/O error or if the name of
1384** the file given in the second argument is illegal. If SQLITE_OK
1385** is returned, then non-zero or zero is written into *pResOut to indicate
1386** whether or not the file is accessible.
1387**
1388** ^SQLite will always allocate at least mxPathname+1 bytes for the
1389** output buffer xFullPathname. The exact size of the output buffer
1390** is also passed as a parameter to both methods. If the output buffer
1391** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1392** handled as a fatal error by SQLite, vfs implementations should endeavor
1393** to prevent this by setting mxPathname to a sufficiently large value.
1394**
1395** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1396** interfaces are not strictly a part of the filesystem, but they are
1397** included in the VFS structure for completeness.
1398** The xRandomness() function attempts to return nBytes bytes
1399** of good-quality randomness into zOut. The return value is
1400** the actual number of bytes of randomness obtained.
1401** The xSleep() method causes the calling thread to sleep for at
1402** least the number of microseconds given. ^The xCurrentTime()
1403** method returns a Julian Day Number for the current date and time as
1404** a floating point value.
1405** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1406** Day Number multiplied by 86400000 (the number of milliseconds in
1407** a 24-hour day).
1408** ^SQLite will use the xCurrentTimeInt64() method to get the current
1409** date and time if that method is available (if iVersion is 2 or
1410** greater and the function pointer is not NULL) and will fall back
1411** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1412**
1413** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1414** are not used by the SQLite core. These optional interfaces are provided
1415** by some VFSes to facilitate testing of the VFS code. By overriding
1416** system calls with functions under its control, a test program can
1417** simulate faults and error conditions that would otherwise be difficult
1418** or impossible to induce. The set of system calls that can be overridden
1419** varies from one VFS to another, and from one version of the same VFS to the
1420** next. Applications that use these interfaces must be prepared for any
1421** or all of these interfaces to be NULL or for their behavior to change
1422** from one release to the next. Applications must not attempt to access
1423** any of these methods if the iVersion of the VFS is less than 3.
1424*/
1425typedef struct sqlite3_vfs sqlite3_vfs;
1426typedef void (*sqlite3_syscall_ptr)(void);
1427struct sqlite3_vfs {
1428 int iVersion; /* Structure version number (currently 3) */
1429 int szOsFile; /* Size of subclassed sqlite3_file */
1430 int mxPathname; /* Maximum file pathname length */
1431 sqlite3_vfs *pNext; /* Next registered VFS */
1432 const char *zName; /* Name of this virtual file system */
1433 void *pAppData; /* Pointer to application-specific data */
1434 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1435 int flags, int *pOutFlags);
1436 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1437 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1438 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1439 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1440 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1441 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1442 void (*xDlClose)(sqlite3_vfs*, void*);
1443 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1444 int (*xSleep)(sqlite3_vfs*, int microseconds);
1445 int (*xCurrentTime)(sqlite3_vfs*, double*);
1446 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1447 /*
1448 ** The methods above are in version 1 of the sqlite_vfs object
1449 ** definition. Those that follow are added in version 2 or later
1450 */
1451 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1452 /*
1453 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1454 ** Those below are for version 3 and greater.
1455 */
1456 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1457 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1458 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1459 /*
1460 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1461 ** New fields may be appended in future versions. The iVersion
1462 ** value will increment whenever this happens.
1463 */
1464};
1465
1466/*
1467** CAPI3REF: Flags for the xAccess VFS method
1468**
1469** These integer constants can be used as the third parameter to
1470** the xAccess method of an [sqlite3_vfs] object. They determine
1471** what kind of permissions the xAccess method is looking for.
1472** With SQLITE_ACCESS_EXISTS, the xAccess method
1473** simply checks whether the file exists.
1474** With SQLITE_ACCESS_READWRITE, the xAccess method
1475** checks whether the named directory is both readable and writable
1476** (in other words, if files can be added, removed, and renamed within
1477** the directory).
1478** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1479** [temp_store_directory pragma], though this could change in a future
1480** release of SQLite.
1481** With SQLITE_ACCESS_READ, the xAccess method
1482** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1483** currently unused, though it might be used in a future release of
1484** SQLite.
1485*/
1486#define SQLITE_ACCESS_EXISTS 0
1487#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1488#define SQLITE_ACCESS_READ 2 /* Unused */
1489
1490/*
1491** CAPI3REF: Flags for the xShmLock VFS method
1492**
1493** These integer constants define the various locking operations
1494** allowed by the xShmLock method of [sqlite3_io_methods]. The
1495** following are the only legal combinations of flags to the
1496** xShmLock method:
1497**
1498** <ul>
1499** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1500** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1501** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1502** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1503** </ul>
1504**
1505** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1506** was given on the corresponding lock.
1507**
1508** The xShmLock method can transition between unlocked and SHARED or
1509** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1510** and EXCLUSIVE.
1511*/
1512#define SQLITE_SHM_UNLOCK 1
1513#define SQLITE_SHM_LOCK 2
1514#define SQLITE_SHM_SHARED 4
1515#define SQLITE_SHM_EXCLUSIVE 8
1516
1517/*
1518** CAPI3REF: Maximum xShmLock index
1519**
1520** The xShmLock method on [sqlite3_io_methods] may use values
1521** between 0 and this upper bound as its "offset" argument.
1522** The SQLite core will never attempt to acquire or release a
1523** lock outside of this range
1524*/
1525#define SQLITE_SHM_NLOCK 8
1526
1527
1528/*
1529** CAPI3REF: Initialize The SQLite Library
1530**
1531** ^The sqlite3_initialize() routine initializes the
1532** SQLite library. ^The sqlite3_shutdown() routine
1533** deallocates any resources that were allocated by sqlite3_initialize().
1534** These routines are designed to aid in process initialization and
1535** shutdown on embedded systems. Workstation applications using
1536** SQLite normally do not need to invoke either of these routines.
1537**
1538** A call to sqlite3_initialize() is an "effective" call if it is
1539** the first time sqlite3_initialize() is invoked during the lifetime of
1540** the process, or if it is the first time sqlite3_initialize() is invoked
1541** following a call to sqlite3_shutdown(). ^(Only an effective call
1542** of sqlite3_initialize() does any initialization. All other calls
1543** are harmless no-ops.)^
1544**
1545** A call to sqlite3_shutdown() is an "effective" call if it is the first
1546** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1547** an effective call to sqlite3_shutdown() does any deinitialization.
1548** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1549**
1550** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1551** is not. The sqlite3_shutdown() interface must only be called from a
1552** single thread. All open [database connections] must be closed and all
1553** other SQLite resources must be deallocated prior to invoking
1554** sqlite3_shutdown().
1555**
1556** Among other things, ^sqlite3_initialize() will invoke
1557** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1558** will invoke sqlite3_os_end().
1559**
1560** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1561** ^If for some reason, sqlite3_initialize() is unable to initialize
1562** the library (perhaps it is unable to allocate a needed resource such
1563** as a mutex) it returns an [error code] other than [SQLITE_OK].
1564**
1565** ^The sqlite3_initialize() routine is called internally by many other
1566** SQLite interfaces so that an application usually does not need to
1567** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1568** calls sqlite3_initialize() so the SQLite library will be automatically
1569** initialized when [sqlite3_open()] is called if it has not be initialized
1570** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1571** compile-time option, then the automatic calls to sqlite3_initialize()
1572** are omitted and the application must call sqlite3_initialize() directly
1573** prior to using any other SQLite interface. For maximum portability,
1574** it is recommended that applications always invoke sqlite3_initialize()
1575** directly prior to using any other SQLite interface. Future releases
1576** of SQLite may require this. In other words, the behavior exhibited
1577** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1578** default behavior in some future release of SQLite.
1579**
1580** The sqlite3_os_init() routine does operating-system specific
1581** initialization of the SQLite library. The sqlite3_os_end()
1582** routine undoes the effect of sqlite3_os_init(). Typical tasks
1583** performed by these routines include allocation or deallocation
1584** of static resources, initialization of global variables,
1585** setting up a default [sqlite3_vfs] module, or setting up
1586** a default configuration using [sqlite3_config()].
1587**
1588** The application should never invoke either sqlite3_os_init()
1589** or sqlite3_os_end() directly. The application should only invoke
1590** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1591** interface is called automatically by sqlite3_initialize() and
1592** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1593** implementations for sqlite3_os_init() and sqlite3_os_end()
1594** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1595** When [custom builds | built for other platforms]
1596** (using the [SQLITE_OS_OTHER=1] compile-time
1597** option) the application must supply a suitable implementation for
1598** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1599** implementation of sqlite3_os_init() or sqlite3_os_end()
1600** must return [SQLITE_OK] on success and some other [error code] upon
1601** failure.
1602*/
1603SQLITE_API int sqlite3_initialize(void);
1604SQLITE_API int sqlite3_shutdown(void);
1605SQLITE_API int sqlite3_os_init(void);
1606SQLITE_API int sqlite3_os_end(void);
1607
1608/*
1609** CAPI3REF: Configuring The SQLite Library
1610**
1611** The sqlite3_config() interface is used to make global configuration
1612** changes to SQLite in order to tune SQLite to the specific needs of
1613** the application. The default configuration is recommended for most
1614** applications and so this routine is usually not necessary. It is
1615** provided to support rare applications with unusual needs.
1616**
1617** <b>The sqlite3_config() interface is not threadsafe. The application
1618** must ensure that no other SQLite interfaces are invoked by other
1619** threads while sqlite3_config() is running.</b>
1620**
1621** The sqlite3_config() interface
1622** may only be invoked prior to library initialization using
1623** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1624** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1625** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1626** Note, however, that ^sqlite3_config() can be called as part of the
1627** implementation of an application-defined [sqlite3_os_init()].
1628**
1629** The first argument to sqlite3_config() is an integer
1630** [configuration option] that determines
1631** what property of SQLite is to be configured. Subsequent arguments
1632** vary depending on the [configuration option]
1633** in the first argument.
1634**
1635** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1636** ^If the option is unknown or SQLite is unable to set the option
1637** then this routine returns a non-zero [error code].
1638*/
1639SQLITE_API int sqlite3_config(int, ...);
1640
1641/*
1642** CAPI3REF: Configure database connections
1643** METHOD: sqlite3
1644**
1645** The sqlite3_db_config() interface is used to make configuration
1646** changes to a [database connection]. The interface is similar to
1647** [sqlite3_config()] except that the changes apply to a single
1648** [database connection] (specified in the first argument).
1649**
1650** The second argument to sqlite3_db_config(D,V,...) is the
1651** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1652** that indicates what aspect of the [database connection] is being configured.
1653** Subsequent arguments vary depending on the configuration verb.
1654**
1655** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1656** the call is considered successful.
1657*/
1658SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1659
1660/*
1661** CAPI3REF: Memory Allocation Routines
1662**
1663** An instance of this object defines the interface between SQLite
1664** and low-level memory allocation routines.
1665**
1666** This object is used in only one place in the SQLite interface.
1667** A pointer to an instance of this object is the argument to
1668** [sqlite3_config()] when the configuration option is
1669** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1670** By creating an instance of this object
1671** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1672** during configuration, an application can specify an alternative
1673** memory allocation subsystem for SQLite to use for all of its
1674** dynamic memory needs.
1675**
1676** Note that SQLite comes with several [built-in memory allocators]
1677** that are perfectly adequate for the overwhelming majority of applications
1678** and that this object is only useful to a tiny minority of applications
1679** with specialized memory allocation requirements. This object is
1680** also used during testing of SQLite in order to specify an alternative
1681** memory allocator that simulates memory out-of-memory conditions in
1682** order to verify that SQLite recovers gracefully from such
1683** conditions.
1684**
1685** The xMalloc, xRealloc, and xFree methods must work like the
1686** malloc(), realloc() and free() functions from the standard C library.
1687** ^SQLite guarantees that the second argument to
1688** xRealloc is always a value returned by a prior call to xRoundup.
1689**
1690** xSize should return the allocated size of a memory allocation
1691** previously obtained from xMalloc or xRealloc. The allocated size
1692** is always at least as big as the requested size but may be larger.
1693**
1694** The xRoundup method returns what would be the allocated size of
1695** a memory allocation given a particular requested size. Most memory
1696** allocators round up memory allocations at least to the next multiple
1697** of 8. Some allocators round up to a larger multiple or to a power of 2.
1698** Every memory allocation request coming in through [sqlite3_malloc()]
1699** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1700** that causes the corresponding memory allocation to fail.
1701**
1702** The xInit method initializes the memory allocator. For example,
1703** it might allocate any required mutexes or initialize internal data
1704** structures. The xShutdown method is invoked (indirectly) by
1705** [sqlite3_shutdown()] and should deallocate any resources acquired
1706** by xInit. The pAppData pointer is used as the only parameter to
1707** xInit and xShutdown.
1708**
1709** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1710** the xInit method, so the xInit method need not be threadsafe. The
1711** xShutdown method is only called from [sqlite3_shutdown()] so it does
1712** not need to be threadsafe either. For all other methods, SQLite
1713** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1714** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1715** it is by default) and so the methods are automatically serialized.
1716** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1717** methods must be threadsafe or else make their own arrangements for
1718** serialization.
1719**
1720** SQLite will never invoke xInit() more than once without an intervening
1721** call to xShutdown().
1722*/
1723typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1724struct sqlite3_mem_methods {
1725 void *(*xMalloc)(int); /* Memory allocation function */
1726 void (*xFree)(void*); /* Free a prior allocation */
1727 void *(*xRealloc)(void*,int); /* Resize an allocation */
1728 int (*xSize)(void*); /* Return the size of an allocation */
1729 int (*xRoundup)(int); /* Round up request size to allocation size */
1730 int (*xInit)(void*); /* Initialize the memory allocator */
1731 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1732 void *pAppData; /* Argument to xInit() and xShutdown() */
1733};
1734
1735/*
1736** CAPI3REF: Configuration Options
1737** KEYWORDS: {configuration option}
1738**
1739** These constants are the available integer configuration options that
1740** can be passed as the first argument to the [sqlite3_config()] interface.
1741**
1742** New configuration options may be added in future releases of SQLite.
1743** Existing configuration options might be discontinued. Applications
1744** should check the return code from [sqlite3_config()] to make sure that
1745** the call worked. The [sqlite3_config()] interface will return a
1746** non-zero [error code] if a discontinued or unsupported configuration option
1747** is invoked.
1748**
1749** <dl>
1750** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1751** <dd>There are no arguments to this option. ^This option sets the
1752** [threading mode] to Single-thread. In other words, it disables
1753** all mutexing and puts SQLite into a mode where it can only be used
1754** by a single thread. ^If SQLite is compiled with
1755** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1756** it is not possible to change the [threading mode] from its default
1757** value of Single-thread and so [sqlite3_config()] will return
1758** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1759** configuration option.</dd>
1760**
1761** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1762** <dd>There are no arguments to this option. ^This option sets the
1763** [threading mode] to Multi-thread. In other words, it disables
1764** mutexing on [database connection] and [prepared statement] objects.
1765** The application is responsible for serializing access to
1766** [database connections] and [prepared statements]. But other mutexes
1767** are enabled so that SQLite will be safe to use in a multi-threaded
1768** environment as long as no two threads attempt to use the same
1769** [database connection] at the same time. ^If SQLite is compiled with
1770** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1771** it is not possible to set the Multi-thread [threading mode] and
1772** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1773** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1774**
1775** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1776** <dd>There are no arguments to this option. ^This option sets the
1777** [threading mode] to Serialized. In other words, this option enables
1778** all mutexes including the recursive
1779** mutexes on [database connection] and [prepared statement] objects.
1780** In this mode (which is the default when SQLite is compiled with
1781** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1782** to [database connections] and [prepared statements] so that the
1783** application is free to use the same [database connection] or the
1784** same [prepared statement] in different threads at the same time.
1785** ^If SQLite is compiled with
1786** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1787** it is not possible to set the Serialized [threading mode] and
1788** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1789** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1790**
1791** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1792** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1793** a pointer to an instance of the [sqlite3_mem_methods] structure.
1794** The argument specifies
1795** alternative low-level memory allocation routines to be used in place of
1796** the memory allocation routines built into SQLite.)^ ^SQLite makes
1797** its own private copy of the content of the [sqlite3_mem_methods] structure
1798** before the [sqlite3_config()] call returns.</dd>
1799**
1800** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1801** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1802** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1803** The [sqlite3_mem_methods]
1804** structure is filled with the currently defined memory allocation routines.)^
1805** This option can be used to overload the default memory allocation
1806** routines with a wrapper that simulations memory allocation failure or
1807** tracks memory usage, for example. </dd>
1808**
1809** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1810** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1811** type int, interpreted as a boolean, which if true provides a hint to
1812** SQLite that it should avoid large memory allocations if possible.
1813** SQLite will run faster if it is free to make large memory allocations,
1814** but some application might prefer to run slower in exchange for
1815** guarantees about memory fragmentation that are possible if large
1816** allocations are avoided. This hint is normally off.
1817** </dd>
1818**
1819** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1820** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1821** interpreted as a boolean, which enables or disables the collection of
1822** memory allocation statistics. ^(When memory allocation statistics are
1823** disabled, the following SQLite interfaces become non-operational:
1824** <ul>
1825** <li> [sqlite3_hard_heap_limit64()]
1826** <li> [sqlite3_memory_used()]
1827** <li> [sqlite3_memory_highwater()]
1828** <li> [sqlite3_soft_heap_limit64()]
1829** <li> [sqlite3_status64()]
1830** </ul>)^
1831** ^Memory allocation statistics are enabled by default unless SQLite is
1832** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1833** allocation statistics are disabled by default.
1834** </dd>
1835**
1836** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1837** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1838** </dd>
1839**
1840** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1841** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1842** that SQLite can use for the database page cache with the default page
1843** cache implementation.
1844** This configuration option is a no-op if an application-defined page
1845** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1846** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1847** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1848** and the number of cache lines (N).
1849** The sz argument should be the size of the largest database page
1850** (a power of two between 512 and 65536) plus some extra bytes for each
1851** page header. ^The number of extra bytes needed by the page header
1852** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1853** ^It is harmless, apart from the wasted memory,
1854** for the sz parameter to be larger than necessary. The pMem
1855** argument must be either a NULL pointer or a pointer to an 8-byte
1856** aligned block of memory of at least sz*N bytes, otherwise
1857** subsequent behavior is undefined.
1858** ^When pMem is not NULL, SQLite will strive to use the memory provided
1859** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1860** a page cache line is larger than sz bytes or if all of the pMem buffer
1861** is exhausted.
1862** ^If pMem is NULL and N is non-zero, then each database connection
1863** does an initial bulk allocation for page cache memory
1864** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1865** of -1024*N bytes if N is negative, . ^If additional
1866** page cache memory is needed beyond what is provided by the initial
1867** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1868** additional cache line. </dd>
1869**
1870** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1871** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1872** that SQLite will use for all of its dynamic memory allocation needs
1873** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1874** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1875** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1876** [SQLITE_ERROR] if invoked otherwise.
1877** ^There are three arguments to SQLITE_CONFIG_HEAP:
1878** An 8-byte aligned pointer to the memory,
1879** the number of bytes in the memory buffer, and the minimum allocation size.
1880** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1881** to using its default memory allocator (the system malloc() implementation),
1882** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1883** memory pointer is not NULL then the alternative memory
1884** allocator is engaged to handle all of SQLites memory allocation needs.
1885** The first pointer (the memory pointer) must be aligned to an 8-byte
1886** boundary or subsequent behavior of SQLite will be undefined.
1887** The minimum allocation size is capped at 2**12. Reasonable values
1888** for the minimum allocation size are 2**5 through 2**8.</dd>
1889**
1890** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1891** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1892** pointer to an instance of the [sqlite3_mutex_methods] structure.
1893** The argument specifies alternative low-level mutex routines to be used
1894** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1895** the content of the [sqlite3_mutex_methods] structure before the call to
1896** [sqlite3_config()] returns. ^If SQLite is compiled with
1897** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1898** the entire mutexing subsystem is omitted from the build and hence calls to
1899** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1900** return [SQLITE_ERROR].</dd>
1901**
1902** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1903** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1904** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1905** [sqlite3_mutex_methods]
1906** structure is filled with the currently defined mutex routines.)^
1907** This option can be used to overload the default mutex allocation
1908** routines with a wrapper used to track mutex usage for performance
1909** profiling or testing, for example. ^If SQLite is compiled with
1910** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1911** the entire mutexing subsystem is omitted from the build and hence calls to
1912** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1913** return [SQLITE_ERROR].</dd>
1914**
1915** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1916** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1917** the default size of lookaside memory on each [database connection].
1918** The first argument is the
1919** size of each lookaside buffer slot and the second is the number of
1920** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1921** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1922** option to [sqlite3_db_config()] can be used to change the lookaside
1923** configuration on individual connections.)^ </dd>
1924**
1925** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1926** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1927** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1928** the interface to a custom page cache implementation.)^
1929** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1930**
1931** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1932** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1933** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1934** the current page cache implementation into that object.)^ </dd>
1935**
1936** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1937** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1938** global [error log].
1939** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1940** function with a call signature of void(*)(void*,int,const char*),
1941** and a pointer to void. ^If the function pointer is not NULL, it is
1942** invoked by [sqlite3_log()] to process each logging event. ^If the
1943** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1944** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1945** passed through as the first parameter to the application-defined logger
1946** function whenever that function is invoked. ^The second parameter to
1947** the logger function is a copy of the first parameter to the corresponding
1948** [sqlite3_log()] call and is intended to be a [result code] or an
1949** [extended result code]. ^The third parameter passed to the logger is
1950** log message after formatting via [sqlite3_snprintf()].
1951** The SQLite logging interface is not reentrant; the logger function
1952** supplied by the application must not invoke any SQLite interface.
1953** In a multi-threaded application, the application-defined logger
1954** function must be threadsafe. </dd>
1955**
1956** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1957** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1958** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1959** then URI handling is globally disabled.)^ ^If URI handling is globally
1960** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1961** [sqlite3_open16()] or
1962** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1963** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1964** connection is opened. ^If it is globally disabled, filenames are
1965** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1966** database connection is opened. ^(By default, URI handling is globally
1967** disabled. The default value may be changed by compiling with the
1968** [SQLITE_USE_URI] symbol defined.)^
1969**
1970** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1971** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1972** argument which is interpreted as a boolean in order to enable or disable
1973** the use of covering indices for full table scans in the query optimizer.
1974** ^The default setting is determined
1975** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1976** if that compile-time option is omitted.
1977** The ability to disable the use of covering indices for full table scans
1978** is because some incorrectly coded legacy applications might malfunction
1979** when the optimization is enabled. Providing the ability to
1980** disable the optimization allows the older, buggy application code to work
1981** without change even with newer versions of SQLite.
1982**
1983** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1984** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1985** <dd> These options are obsolete and should not be used by new code.
1986** They are retained for backwards compatibility but are now no-ops.
1987** </dd>
1988**
1989** [[SQLITE_CONFIG_SQLLOG]]
1990** <dt>SQLITE_CONFIG_SQLLOG
1991** <dd>This option is only available if sqlite is compiled with the
1992** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1993** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1994** The second should be of type (void*). The callback is invoked by the library
1995** in three separate circumstances, identified by the value passed as the
1996** fourth parameter. If the fourth parameter is 0, then the database connection
1997** passed as the second argument has just been opened. The third argument
1998** points to a buffer containing the name of the main database file. If the
1999** fourth parameter is 1, then the SQL statement that the third parameter
2000** points to has just been executed. Or, if the fourth parameter is 2, then
2001** the connection being passed as the second parameter is being closed. The
2002** third parameter is passed NULL In this case. An example of using this
2003** configuration option can be seen in the "test_sqllog.c" source file in
2004** the canonical SQLite source tree.</dd>
2005**
2006** [[SQLITE_CONFIG_MMAP_SIZE]]
2007** <dt>SQLITE_CONFIG_MMAP_SIZE
2008** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2009** that are the default mmap size limit (the default setting for
2010** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2011** ^The default setting can be overridden by each database connection using
2012** either the [PRAGMA mmap_size] command, or by using the
2013** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2014** will be silently truncated if necessary so that it does not exceed the
2015** compile-time maximum mmap size set by the
2016** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2017** ^If either argument to this option is negative, then that argument is
2018** changed to its compile-time default.
2019**
2020** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2021** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2022** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2023** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2024** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2025** that specifies the maximum size of the created heap.
2026**
2027** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2028** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2029** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2030** is a pointer to an integer and writes into that integer the number of extra
2031** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2032** The amount of extra space required can change depending on the compiler,
2033** target platform, and SQLite version.
2034**
2035** [[SQLITE_CONFIG_PMASZ]]
2036** <dt>SQLITE_CONFIG_PMASZ
2037** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2038** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2039** sorter to that integer. The default minimum PMA Size is set by the
2040** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2041** to help with sort operations when multithreaded sorting
2042** is enabled (using the [PRAGMA threads] command) and the amount of content
2043** to be sorted exceeds the page size times the minimum of the
2044** [PRAGMA cache_size] setting and this value.
2045**
2046** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2047** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2048** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2049** becomes the [statement journal] spill-to-disk threshold.
2050** [Statement journals] are held in memory until their size (in bytes)
2051** exceeds this threshold, at which point they are written to disk.
2052** Or if the threshold is -1, statement journals are always held
2053** exclusively in memory.
2054** Since many statement journals never become large, setting the spill
2055** threshold to a value such as 64KiB can greatly reduce the amount of
2056** I/O required to support statement rollback.
2057** The default value for this setting is controlled by the
2058** [SQLITE_STMTJRNL_SPILL] compile-time option.
2059**
2060** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2061** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2062** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2063** of type (int) - the new value of the sorter-reference size threshold.
2064** Usually, when SQLite uses an external sort to order records according
2065** to an ORDER BY clause, all fields required by the caller are present in the
2066** sorted records. However, if SQLite determines based on the declared type
2067** of a table column that its values are likely to be very large - larger
2068** than the configured sorter-reference size threshold - then a reference
2069** is stored in each sorted record and the required column values loaded
2070** from the database as records are returned in sorted order. The default
2071** value for this option is to never use this optimization. Specifying a
2072** negative value for this option restores the default behaviour.
2073** This option is only available if SQLite is compiled with the
2074** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2075**
2076** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2077** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2078** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2079** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2080** database created using [sqlite3_deserialize()]. This default maximum
2081** size can be adjusted up or down for individual databases using the
2082** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2083** configuration setting is never used, then the default maximum is determined
2084** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2085** compile-time option is not set, then the default maximum is 1073741824.
2086** </dl>
2087*/
2088#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2089#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2090#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2091#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2092#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2093#define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2094#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2095#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2096#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2097#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2098#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2099/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2100#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2101#define SQLITE_CONFIG_PCACHE 14 /* no-op */
2102#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2103#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2104#define SQLITE_CONFIG_URI 17 /* int */
2105#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2106#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2107#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2108#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2109#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2110#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2111#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2112#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2113#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2114#define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2115#define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2116#define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2117
2118/*
2119** CAPI3REF: Database Connection Configuration Options
2120**
2121** These constants are the available integer configuration options that
2122** can be passed as the second argument to the [sqlite3_db_config()] interface.
2123**
2124** New configuration options may be added in future releases of SQLite.
2125** Existing configuration options might be discontinued. Applications
2126** should check the return code from [sqlite3_db_config()] to make sure that
2127** the call worked. ^The [sqlite3_db_config()] interface will return a
2128** non-zero [error code] if a discontinued or unsupported configuration option
2129** is invoked.
2130**
2131** <dl>
2132** [[SQLITE_DBCONFIG_LOOKASIDE]]
2133** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2134** <dd> ^This option takes three additional arguments that determine the
2135** [lookaside memory allocator] configuration for the [database connection].
2136** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2137** pointer to a memory buffer to use for lookaside memory.
2138** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2139** may be NULL in which case SQLite will allocate the
2140** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2141** size of each lookaside buffer slot. ^The third argument is the number of
2142** slots. The size of the buffer in the first argument must be greater than
2143** or equal to the product of the second and third arguments. The buffer
2144** must be aligned to an 8-byte boundary. ^If the second argument to
2145** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2146** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2147** configuration for a database connection can only be changed when that
2148** connection is not currently using lookaside memory, or in other words
2149** when the "current value" returned by
2150** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
2151** Any attempt to change the lookaside memory configuration when lookaside
2152** memory is in use leaves the configuration unchanged and returns
2153** [SQLITE_BUSY].)^</dd>
2154**
2155** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2156** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2157** <dd> ^This option is used to enable or disable the enforcement of
2158** [foreign key constraints]. There should be two additional arguments.
2159** The first argument is an integer which is 0 to disable FK enforcement,
2160** positive to enable FK enforcement or negative to leave FK enforcement
2161** unchanged. The second parameter is a pointer to an integer into which
2162** is written 0 or 1 to indicate whether FK enforcement is off or on
2163** following this call. The second parameter may be a NULL pointer, in
2164** which case the FK enforcement setting is not reported back. </dd>
2165**
2166** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2167** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2168** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2169** There should be two additional arguments.
2170** The first argument is an integer which is 0 to disable triggers,
2171** positive to enable triggers or negative to leave the setting unchanged.
2172** The second parameter is a pointer to an integer into which
2173** is written 0 or 1 to indicate whether triggers are disabled or enabled
2174** following this call. The second parameter may be a NULL pointer, in
2175** which case the trigger setting is not reported back.
2176**
2177** <p>Originally this option disabled all triggers. ^(However, since
2178** SQLite version 3.35.0, TEMP triggers are still allowed even if
2179** this option is off. So, in other words, this option now only disables
2180** triggers in the main database schema or in the schemas of ATTACH-ed
2181** databases.)^ </dd>
2182**
2183** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2184** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2185** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2186** There should be two additional arguments.
2187** The first argument is an integer which is 0 to disable views,
2188** positive to enable views or negative to leave the setting unchanged.
2189** The second parameter is a pointer to an integer into which
2190** is written 0 or 1 to indicate whether views are disabled or enabled
2191** following this call. The second parameter may be a NULL pointer, in
2192** which case the view setting is not reported back.
2193**
2194** <p>Originally this option disabled all views. ^(However, since
2195** SQLite version 3.35.0, TEMP views are still allowed even if
2196** this option is off. So, in other words, this option now only disables
2197** views in the main database schema or in the schemas of ATTACH-ed
2198** databases.)^ </dd>
2199**
2200** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2201** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2202** <dd> ^This option is used to enable or disable the
2203** [fts3_tokenizer()] function which is part of the
2204** [FTS3] full-text search engine extension.
2205** There should be two additional arguments.
2206** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2207** positive to enable fts3_tokenizer() or negative to leave the setting
2208** unchanged.
2209** The second parameter is a pointer to an integer into which
2210** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2211** following this call. The second parameter may be a NULL pointer, in
2212** which case the new setting is not reported back. </dd>
2213**
2214** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2215** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2216** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2217** interface independently of the [load_extension()] SQL function.
2218** The [sqlite3_enable_load_extension()] API enables or disables both the
2219** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2220** There should be two additional arguments.
2221** When the first argument to this interface is 1, then only the C-API is
2222** enabled and the SQL function remains disabled. If the first argument to
2223** this interface is 0, then both the C-API and the SQL function are disabled.
2224** If the first argument is -1, then no changes are made to state of either the
2225** C-API or the SQL function.
2226** The second parameter is a pointer to an integer into which
2227** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2228** is disabled or enabled following this call. The second parameter may
2229** be a NULL pointer, in which case the new setting is not reported back.
2230** </dd>
2231**
2232** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2233** <dd> ^This option is used to change the name of the "main" database
2234** schema. ^The sole argument is a pointer to a constant UTF8 string
2235** which will become the new schema name in place of "main". ^SQLite
2236** does not make a copy of the new main schema name string, so the application
2237** must ensure that the argument passed into this DBCONFIG option is unchanged
2238** until after the database connection closes.
2239** </dd>
2240**
2241** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2242** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2243** <dd> Usually, when a database in wal mode is closed or detached from a
2244** database handle, SQLite checks if this will mean that there are now no
2245** connections at all to the database. If so, it performs a checkpoint
2246** operation before closing the connection. This option may be used to
2247** override this behaviour. The first parameter passed to this operation
2248** is an integer - positive to disable checkpoints-on-close, or zero (the
2249** default) to enable them, and negative to leave the setting unchanged.
2250** The second parameter is a pointer to an integer
2251** into which is written 0 or 1 to indicate whether checkpoints-on-close
2252** have been disabled - 0 if they are not disabled, 1 if they are.
2253** </dd>
2254**
2255** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2256** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2257** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2258** a single SQL query statement will always use the same algorithm regardless
2259** of values of [bound parameters].)^ The QPSG disables some query optimizations
2260** that look at the values of bound parameters, which can make some queries
2261** slower. But the QPSG has the advantage of more predictable behavior. With
2262** the QPSG active, SQLite will always use the same query plan in the field as
2263** was used during testing in the lab.
2264** The first argument to this setting is an integer which is 0 to disable
2265** the QPSG, positive to enable QPSG, or negative to leave the setting
2266** unchanged. The second parameter is a pointer to an integer into which
2267** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2268** following this call.
2269** </dd>
2270**
2271** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2272** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2273** include output for any operations performed by trigger programs. This
2274** option is used to set or clear (the default) a flag that governs this
2275** behavior. The first parameter passed to this operation is an integer -
2276** positive to enable output for trigger programs, or zero to disable it,
2277** or negative to leave the setting unchanged.
2278** The second parameter is a pointer to an integer into which is written
2279** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2280** it is not disabled, 1 if it is.
2281** </dd>
2282**
2283** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2284** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2285** [VACUUM] in order to reset a database back to an empty database
2286** with no schema and no content. The following process works even for
2287** a badly corrupted database file:
2288** <ol>
2289** <li> If the database connection is newly opened, make sure it has read the
2290** database schema by preparing then discarding some query against the
2291** database, or calling sqlite3_table_column_metadata(), ignoring any
2292** errors. This step is only necessary if the application desires to keep
2293** the database in WAL mode after the reset if it was in WAL mode before
2294** the reset.
2295** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2296** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2297** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2298** </ol>
2299** Because resetting a database is destructive and irreversible, the
2300** process requires the use of this obscure API and multiple steps to help
2301** ensure that it does not happen by accident.
2302**
2303** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2304** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2305** "defensive" flag for a database connection. When the defensive
2306** flag is enabled, language features that allow ordinary SQL to
2307** deliberately corrupt the database file are disabled. The disabled
2308** features include but are not limited to the following:
2309** <ul>
2310** <li> The [PRAGMA writable_schema=ON] statement.
2311** <li> The [PRAGMA journal_mode=OFF] statement.
2312** <li> Writes to the [sqlite_dbpage] virtual table.
2313** <li> Direct writes to [shadow tables].
2314** </ul>
2315** </dd>
2316**
2317** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2318** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2319** "writable_schema" flag. This has the same effect and is logically equivalent
2320** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2321** The first argument to this setting is an integer which is 0 to disable
2322** the writable_schema, positive to enable writable_schema, or negative to
2323** leave the setting unchanged. The second parameter is a pointer to an
2324** integer into which is written 0 or 1 to indicate whether the writable_schema
2325** is enabled or disabled following this call.
2326** </dd>
2327**
2328** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2329** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2330** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2331** the legacy behavior of the [ALTER TABLE RENAME] command such it
2332** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2333** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2334** additional information. This feature can also be turned on and off
2335** using the [PRAGMA legacy_alter_table] statement.
2336** </dd>
2337**
2338** [[SQLITE_DBCONFIG_DQS_DML]]
2339** <dt>SQLITE_DBCONFIG_DQS_DML</td>
2340** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2341** the legacy [double-quoted string literal] misfeature for DML statements
2342** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2343** default value of this setting is determined by the [-DSQLITE_DQS]
2344** compile-time option.
2345** </dd>
2346**
2347** [[SQLITE_DBCONFIG_DQS_DDL]]
2348** <dt>SQLITE_DBCONFIG_DQS_DDL</td>
2349** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2350** the legacy [double-quoted string literal] misfeature for DDL statements,
2351** such as CREATE TABLE and CREATE INDEX. The
2352** default value of this setting is determined by the [-DSQLITE_DQS]
2353** compile-time option.
2354** </dd>
2355**
2356** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2357** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</td>
2358** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2359** assume that database schemas are untainted by malicious content.
2360** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2361** takes additional defensive steps to protect the application from harm
2362** including:
2363** <ul>
2364** <li> Prohibit the use of SQL functions inside triggers, views,
2365** CHECK constraints, DEFAULT clauses, expression indexes,
2366** partial indexes, or generated columns
2367** unless those functions are tagged with [SQLITE_INNOCUOUS].
2368** <li> Prohibit the use of virtual tables inside of triggers or views
2369** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2370** </ul>
2371** This setting defaults to "on" for legacy compatibility, however
2372** all applications are advised to turn it off if possible. This setting
2373** can also be controlled using the [PRAGMA trusted_schema] statement.
2374** </dd>
2375**
2376** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2377** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</td>
2378** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2379** the legacy file format flag. When activated, this flag causes all newly
2380** created database file to have a schema format version number (the 4-byte
2381** integer found at offset 44 into the database header) of 1. This in turn
2382** means that the resulting database file will be readable and writable by
2383** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2384** newly created databases are generally not understandable by SQLite versions
2385** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2386** is now scarcely any need to generated database files that are compatible
2387** all the way back to version 3.0.0, and so this setting is of little
2388** practical use, but is provided so that SQLite can continue to claim the
2389** ability to generate new database files that are compatible with version
2390** 3.0.0.
2391** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2392** the [VACUUM] command will fail with an obscure error when attempting to
2393** process a table with generated columns and a descending index. This is
2394** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2395** either generated columns or decending indexes.
2396** </dd>
2397** </dl>
2398*/
2399#define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2400#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2401#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2402#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2403#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2404#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2405#define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2406#define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2407#define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2408#define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2409#define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2410#define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2411#define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2412#define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2413#define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2414#define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2415#define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2416#define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2417#define SQLITE_DBCONFIG_MAX 1017 /* Largest DBCONFIG */
2418
2419/*
2420** CAPI3REF: Enable Or Disable Extended Result Codes
2421** METHOD: sqlite3
2422**
2423** ^The sqlite3_extended_result_codes() routine enables or disables the
2424** [extended result codes] feature of SQLite. ^The extended result
2425** codes are disabled by default for historical compatibility.
2426*/
2427SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2428
2429/*
2430** CAPI3REF: Last Insert Rowid
2431** METHOD: sqlite3
2432**
2433** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2434** has a unique 64-bit signed
2435** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2436** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2437** names are not also used by explicitly declared columns. ^If
2438** the table has a column of type [INTEGER PRIMARY KEY] then that column
2439** is another alias for the rowid.
2440**
2441** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2442** the most recent successful [INSERT] into a rowid table or [virtual table]
2443** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2444** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2445** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2446** zero.
2447**
2448** As well as being set automatically as rows are inserted into database
2449** tables, the value returned by this function may be set explicitly by
2450** [sqlite3_set_last_insert_rowid()]
2451**
2452** Some virtual table implementations may INSERT rows into rowid tables as
2453** part of committing a transaction (e.g. to flush data accumulated in memory
2454** to disk). In this case subsequent calls to this function return the rowid
2455** associated with these internal INSERT operations, which leads to
2456** unintuitive results. Virtual table implementations that do write to rowid
2457** tables in this way can avoid this problem by restoring the original
2458** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2459** control to the user.
2460**
2461** ^(If an [INSERT] occurs within a trigger then this routine will
2462** return the [rowid] of the inserted row as long as the trigger is
2463** running. Once the trigger program ends, the value returned
2464** by this routine reverts to what it was before the trigger was fired.)^
2465**
2466** ^An [INSERT] that fails due to a constraint violation is not a
2467** successful [INSERT] and does not change the value returned by this
2468** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2469** and INSERT OR ABORT make no changes to the return value of this
2470** routine when their insertion fails. ^(When INSERT OR REPLACE
2471** encounters a constraint violation, it does not fail. The
2472** INSERT continues to completion after deleting rows that caused
2473** the constraint problem so INSERT OR REPLACE will always change
2474** the return value of this interface.)^
2475**
2476** ^For the purposes of this routine, an [INSERT] is considered to
2477** be successful even if it is subsequently rolled back.
2478**
2479** This function is accessible to SQL statements via the
2480** [last_insert_rowid() SQL function].
2481**
2482** If a separate thread performs a new [INSERT] on the same
2483** database connection while the [sqlite3_last_insert_rowid()]
2484** function is running and thus changes the last insert [rowid],
2485** then the value returned by [sqlite3_last_insert_rowid()] is
2486** unpredictable and might not equal either the old or the new
2487** last insert [rowid].
2488*/
2489SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2490
2491/*
2492** CAPI3REF: Set the Last Insert Rowid value.
2493** METHOD: sqlite3
2494**
2495** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2496** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2497** without inserting a row into the database.
2498*/
2499SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2500
2501/*
2502** CAPI3REF: Count The Number Of Rows Modified
2503** METHOD: sqlite3
2504**
2505** ^These functions return the number of rows modified, inserted or
2506** deleted by the most recently completed INSERT, UPDATE or DELETE
2507** statement on the database connection specified by the only parameter.
2508** The two functions are identical except for the type of the return value
2509** and that if the number of rows modified by the most recent INSERT, UPDATE
2510** or DELETE is greater than the maximum value supported by type "int", then
2511** the return value of sqlite3_changes() is undefined. ^Executing any other
2512** type of SQL statement does not modify the value returned by these functions.
2513**
2514** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2515** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2516** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2517**
2518** Changes to a view that are intercepted by
2519** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2520** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2521** DELETE statement run on a view is always zero. Only changes made to real
2522** tables are counted.
2523**
2524** Things are more complicated if the sqlite3_changes() function is
2525** executed while a trigger program is running. This may happen if the
2526** program uses the [changes() SQL function], or if some other callback
2527** function invokes sqlite3_changes() directly. Essentially:
2528**
2529** <ul>
2530** <li> ^(Before entering a trigger program the value returned by
2531** sqlite3_changes() function is saved. After the trigger program
2532** has finished, the original value is restored.)^
2533**
2534** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2535** statement sets the value returned by sqlite3_changes()
2536** upon completion as normal. Of course, this value will not include
2537** any changes performed by sub-triggers, as the sqlite3_changes()
2538** value will be saved and restored after each sub-trigger has run.)^
2539** </ul>
2540**
2541** ^This means that if the changes() SQL function (or similar) is used
2542** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2543** returns the value as set when the calling statement began executing.
2544** ^If it is used by the second or subsequent such statement within a trigger
2545** program, the value returned reflects the number of rows modified by the
2546** previous INSERT, UPDATE or DELETE statement within the same trigger.
2547**
2548** If a separate thread makes changes on the same database connection
2549** while [sqlite3_changes()] is running then the value returned
2550** is unpredictable and not meaningful.
2551**
2552** See also:
2553** <ul>
2554** <li> the [sqlite3_total_changes()] interface
2555** <li> the [count_changes pragma]
2556** <li> the [changes() SQL function]
2557** <li> the [data_version pragma]
2558** </ul>
2559*/
2560SQLITE_API int sqlite3_changes(sqlite3*);
2561SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2562
2563/*
2564** CAPI3REF: Total Number Of Rows Modified
2565** METHOD: sqlite3
2566**
2567** ^These functions return the total number of rows inserted, modified or
2568** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2569** since the database connection was opened, including those executed as
2570** part of trigger programs. The two functions are identical except for the
2571** type of the return value and that if the number of rows modified by the
2572** connection exceeds the maximum value supported by type "int", then
2573** the return value of sqlite3_total_changes() is undefined. ^Executing
2574** any other type of SQL statement does not affect the value returned by
2575** sqlite3_total_changes().
2576**
2577** ^Changes made as part of [foreign key actions] are included in the
2578** count, but those made as part of REPLACE constraint resolution are
2579** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2580** are not counted.
2581**
2582** The [sqlite3_total_changes(D)] interface only reports the number
2583** of rows that changed due to SQL statement run against database
2584** connection D. Any changes by other database connections are ignored.
2585** To detect changes against a database file from other database
2586** connections use the [PRAGMA data_version] command or the
2587** [SQLITE_FCNTL_DATA_VERSION] [file control].
2588**
2589** If a separate thread makes changes on the same database connection
2590** while [sqlite3_total_changes()] is running then the value
2591** returned is unpredictable and not meaningful.
2592**
2593** See also:
2594** <ul>
2595** <li> the [sqlite3_changes()] interface
2596** <li> the [count_changes pragma]
2597** <li> the [changes() SQL function]
2598** <li> the [data_version pragma]
2599** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2600** </ul>
2601*/
2602SQLITE_API int sqlite3_total_changes(sqlite3*);
2603SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2604
2605/*
2606** CAPI3REF: Interrupt A Long-Running Query
2607** METHOD: sqlite3
2608**
2609** ^This function causes any pending database operation to abort and
2610** return at its earliest opportunity. This routine is typically
2611** called in response to a user action such as pressing "Cancel"
2612** or Ctrl-C where the user wants a long query operation to halt
2613** immediately.
2614**
2615** ^It is safe to call this routine from a thread different from the
2616** thread that is currently running the database operation. But it
2617** is not safe to call this routine with a [database connection] that
2618** is closed or might close before sqlite3_interrupt() returns.
2619**
2620** ^If an SQL operation is very nearly finished at the time when
2621** sqlite3_interrupt() is called, then it might not have an opportunity
2622** to be interrupted and might continue to completion.
2623**
2624** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2625** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2626** that is inside an explicit transaction, then the entire transaction
2627** will be rolled back automatically.
2628**
2629** ^The sqlite3_interrupt(D) call is in effect until all currently running
2630** SQL statements on [database connection] D complete. ^Any new SQL statements
2631** that are started after the sqlite3_interrupt() call and before the
2632** running statement count reaches zero are interrupted as if they had been
2633** running prior to the sqlite3_interrupt() call. ^New SQL statements
2634** that are started after the running statement count reaches zero are
2635** not effected by the sqlite3_interrupt().
2636** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2637** SQL statements is a no-op and has no effect on SQL statements
2638** that are started after the sqlite3_interrupt() call returns.
2639*/
2640SQLITE_API void sqlite3_interrupt(sqlite3*);
2641
2642/*
2643** CAPI3REF: Determine If An SQL Statement Is Complete
2644**
2645** These routines are useful during command-line input to determine if the
2646** currently entered text seems to form a complete SQL statement or
2647** if additional input is needed before sending the text into
2648** SQLite for parsing. ^These routines return 1 if the input string
2649** appears to be a complete SQL statement. ^A statement is judged to be
2650** complete if it ends with a semicolon token and is not a prefix of a
2651** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2652** string literals or quoted identifier names or comments are not
2653** independent tokens (they are part of the token in which they are
2654** embedded) and thus do not count as a statement terminator. ^Whitespace
2655** and comments that follow the final semicolon are ignored.
2656**
2657** ^These routines return 0 if the statement is incomplete. ^If a
2658** memory allocation fails, then SQLITE_NOMEM is returned.
2659**
2660** ^These routines do not parse the SQL statements thus
2661** will not detect syntactically incorrect SQL.
2662**
2663** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2664** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2665** automatically by sqlite3_complete16(). If that initialization fails,
2666** then the return value from sqlite3_complete16() will be non-zero
2667** regardless of whether or not the input SQL is complete.)^
2668**
2669** The input to [sqlite3_complete()] must be a zero-terminated
2670** UTF-8 string.
2671**
2672** The input to [sqlite3_complete16()] must be a zero-terminated
2673** UTF-16 string in native byte order.
2674*/
2675SQLITE_API int sqlite3_complete(const char *sql);
2676SQLITE_API int sqlite3_complete16(const void *sql);
2677
2678/*
2679** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2680** KEYWORDS: {busy-handler callback} {busy handler}
2681** METHOD: sqlite3
2682**
2683** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2684** that might be invoked with argument P whenever
2685** an attempt is made to access a database table associated with
2686** [database connection] D when another thread
2687** or process has the table locked.
2688** The sqlite3_busy_handler() interface is used to implement
2689** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2690**
2691** ^If the busy callback is NULL, then [SQLITE_BUSY]
2692** is returned immediately upon encountering the lock. ^If the busy callback
2693** is not NULL, then the callback might be invoked with two arguments.
2694**
2695** ^The first argument to the busy handler is a copy of the void* pointer which
2696** is the third argument to sqlite3_busy_handler(). ^The second argument to
2697** the busy handler callback is the number of times that the busy handler has
2698** been invoked previously for the same locking event. ^If the
2699** busy callback returns 0, then no additional attempts are made to
2700** access the database and [SQLITE_BUSY] is returned
2701** to the application.
2702** ^If the callback returns non-zero, then another attempt
2703** is made to access the database and the cycle repeats.
2704**
2705** The presence of a busy handler does not guarantee that it will be invoked
2706** when there is lock contention. ^If SQLite determines that invoking the busy
2707** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2708** to the application instead of invoking the
2709** busy handler.
2710** Consider a scenario where one process is holding a read lock that
2711** it is trying to promote to a reserved lock and
2712** a second process is holding a reserved lock that it is trying
2713** to promote to an exclusive lock. The first process cannot proceed
2714** because it is blocked by the second and the second process cannot
2715** proceed because it is blocked by the first. If both processes
2716** invoke the busy handlers, neither will make any progress. Therefore,
2717** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2718** will induce the first process to release its read lock and allow
2719** the second process to proceed.
2720**
2721** ^The default busy callback is NULL.
2722**
2723** ^(There can only be a single busy handler defined for each
2724** [database connection]. Setting a new busy handler clears any
2725** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2726** or evaluating [PRAGMA busy_timeout=N] will change the
2727** busy handler and thus clear any previously set busy handler.
2728**
2729** The busy callback should not take any actions which modify the
2730** database connection that invoked the busy handler. In other words,
2731** the busy handler is not reentrant. Any such actions
2732** result in undefined behavior.
2733**
2734** A busy handler must not close the database connection
2735** or [prepared statement] that invoked the busy handler.
2736*/
2737SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2738
2739/*
2740** CAPI3REF: Set A Busy Timeout
2741** METHOD: sqlite3
2742**
2743** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2744** for a specified amount of time when a table is locked. ^The handler
2745** will sleep multiple times until at least "ms" milliseconds of sleeping
2746** have accumulated. ^After at least "ms" milliseconds of sleeping,
2747** the handler returns 0 which causes [sqlite3_step()] to return
2748** [SQLITE_BUSY].
2749**
2750** ^Calling this routine with an argument less than or equal to zero
2751** turns off all busy handlers.
2752**
2753** ^(There can only be a single busy handler for a particular
2754** [database connection] at any given moment. If another busy handler
2755** was defined (using [sqlite3_busy_handler()]) prior to calling
2756** this routine, that other busy handler is cleared.)^
2757**
2758** See also: [PRAGMA busy_timeout]
2759*/
2760SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2761
2762/*
2763** CAPI3REF: Convenience Routines For Running Queries
2764** METHOD: sqlite3
2765**
2766** This is a legacy interface that is preserved for backwards compatibility.
2767** Use of this interface is not recommended.
2768**
2769** Definition: A <b>result table</b> is memory data structure created by the
2770** [sqlite3_get_table()] interface. A result table records the
2771** complete query results from one or more queries.
2772**
2773** The table conceptually has a number of rows and columns. But
2774** these numbers are not part of the result table itself. These
2775** numbers are obtained separately. Let N be the number of rows
2776** and M be the number of columns.
2777**
2778** A result table is an array of pointers to zero-terminated UTF-8 strings.
2779** There are (N+1)*M elements in the array. The first M pointers point
2780** to zero-terminated strings that contain the names of the columns.
2781** The remaining entries all point to query results. NULL values result
2782** in NULL pointers. All other values are in their UTF-8 zero-terminated
2783** string representation as returned by [sqlite3_column_text()].
2784**
2785** A result table might consist of one or more memory allocations.
2786** It is not safe to pass a result table directly to [sqlite3_free()].
2787** A result table should be deallocated using [sqlite3_free_table()].
2788**
2789** ^(As an example of the result table format, suppose a query result
2790** is as follows:
2791**
2792** <blockquote><pre>
2793** Name | Age
2794** -----------------------
2795** Alice | 43
2796** Bob | 28
2797** Cindy | 21
2798** </pre></blockquote>
2799**
2800** There are two columns (M==2) and three rows (N==3). Thus the
2801** result table has 8 entries. Suppose the result table is stored
2802** in an array named azResult. Then azResult holds this content:
2803**
2804** <blockquote><pre>
2805** azResult&#91;0] = "Name";
2806** azResult&#91;1] = "Age";
2807** azResult&#91;2] = "Alice";
2808** azResult&#91;3] = "43";
2809** azResult&#91;4] = "Bob";
2810** azResult&#91;5] = "28";
2811** azResult&#91;6] = "Cindy";
2812** azResult&#91;7] = "21";
2813** </pre></blockquote>)^
2814**
2815** ^The sqlite3_get_table() function evaluates one or more
2816** semicolon-separated SQL statements in the zero-terminated UTF-8
2817** string of its 2nd parameter and returns a result table to the
2818** pointer given in its 3rd parameter.
2819**
2820** After the application has finished with the result from sqlite3_get_table(),
2821** it must pass the result table pointer to sqlite3_free_table() in order to
2822** release the memory that was malloced. Because of the way the
2823** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2824** function must not try to call [sqlite3_free()] directly. Only
2825** [sqlite3_free_table()] is able to release the memory properly and safely.
2826**
2827** The sqlite3_get_table() interface is implemented as a wrapper around
2828** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2829** to any internal data structures of SQLite. It uses only the public
2830** interface defined here. As a consequence, errors that occur in the
2831** wrapper layer outside of the internal [sqlite3_exec()] call are not
2832** reflected in subsequent calls to [sqlite3_errcode()] or
2833** [sqlite3_errmsg()].
2834*/
2835SQLITE_API int sqlite3_get_table(
2836 sqlite3 *db, /* An open database */
2837 const char *zSql, /* SQL to be evaluated */
2838 char ***pazResult, /* Results of the query */
2839 int *pnRow, /* Number of result rows written here */
2840 int *pnColumn, /* Number of result columns written here */
2841 char **pzErrmsg /* Error msg written here */
2842);
2843SQLITE_API void sqlite3_free_table(char **result);
2844
2845/*
2846** CAPI3REF: Formatted String Printing Functions
2847**
2848** These routines are work-alikes of the "printf()" family of functions
2849** from the standard C library.
2850** These routines understand most of the common formatting options from
2851** the standard library printf()
2852** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2853** See the [built-in printf()] documentation for details.
2854**
2855** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2856** results into memory obtained from [sqlite3_malloc64()].
2857** The strings returned by these two routines should be
2858** released by [sqlite3_free()]. ^Both routines return a
2859** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2860** memory to hold the resulting string.
2861**
2862** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2863** the standard C library. The result is written into the
2864** buffer supplied as the second parameter whose size is given by
2865** the first parameter. Note that the order of the
2866** first two parameters is reversed from snprintf().)^ This is an
2867** historical accident that cannot be fixed without breaking
2868** backwards compatibility. ^(Note also that sqlite3_snprintf()
2869** returns a pointer to its buffer instead of the number of
2870** characters actually written into the buffer.)^ We admit that
2871** the number of characters written would be a more useful return
2872** value but we cannot change the implementation of sqlite3_snprintf()
2873** now without breaking compatibility.
2874**
2875** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2876** guarantees that the buffer is always zero-terminated. ^The first
2877** parameter "n" is the total size of the buffer, including space for
2878** the zero terminator. So the longest string that can be completely
2879** written will be n-1 characters.
2880**
2881** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2882**
2883** See also: [built-in printf()], [printf() SQL function]
2884*/
2885SQLITE_API char *sqlite3_mprintf(const char*,...);
2886SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
2887SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
2888SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
2889
2890/*
2891** CAPI3REF: Memory Allocation Subsystem
2892**
2893** The SQLite core uses these three routines for all of its own
2894** internal memory allocation needs. "Core" in the previous sentence
2895** does not include operating-system specific [VFS] implementation. The
2896** Windows VFS uses native malloc() and free() for some operations.
2897**
2898** ^The sqlite3_malloc() routine returns a pointer to a block
2899** of memory at least N bytes in length, where N is the parameter.
2900** ^If sqlite3_malloc() is unable to obtain sufficient free
2901** memory, it returns a NULL pointer. ^If the parameter N to
2902** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2903** a NULL pointer.
2904**
2905** ^The sqlite3_malloc64(N) routine works just like
2906** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2907** of a signed 32-bit integer.
2908**
2909** ^Calling sqlite3_free() with a pointer previously returned
2910** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2911** that it might be reused. ^The sqlite3_free() routine is
2912** a no-op if is called with a NULL pointer. Passing a NULL pointer
2913** to sqlite3_free() is harmless. After being freed, memory
2914** should neither be read nor written. Even reading previously freed
2915** memory might result in a segmentation fault or other severe error.
2916** Memory corruption, a segmentation fault, or other severe error
2917** might result if sqlite3_free() is called with a non-NULL pointer that
2918** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2919**
2920** ^The sqlite3_realloc(X,N) interface attempts to resize a
2921** prior memory allocation X to be at least N bytes.
2922** ^If the X parameter to sqlite3_realloc(X,N)
2923** is a NULL pointer then its behavior is identical to calling
2924** sqlite3_malloc(N).
2925** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2926** negative then the behavior is exactly the same as calling
2927** sqlite3_free(X).
2928** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2929** of at least N bytes in size or NULL if insufficient memory is available.
2930** ^If M is the size of the prior allocation, then min(N,M) bytes
2931** of the prior allocation are copied into the beginning of buffer returned
2932** by sqlite3_realloc(X,N) and the prior allocation is freed.
2933** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2934** prior allocation is not freed.
2935**
2936** ^The sqlite3_realloc64(X,N) interfaces works the same as
2937** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2938** of a 32-bit signed integer.
2939**
2940** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2941** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2942** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2943** ^The value returned by sqlite3_msize(X) might be larger than the number
2944** of bytes requested when X was allocated. ^If X is a NULL pointer then
2945** sqlite3_msize(X) returns zero. If X points to something that is not
2946** the beginning of memory allocation, or if it points to a formerly
2947** valid memory allocation that has now been freed, then the behavior
2948** of sqlite3_msize(X) is undefined and possibly harmful.
2949**
2950** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2951** sqlite3_malloc64(), and sqlite3_realloc64()
2952** is always aligned to at least an 8 byte boundary, or to a
2953** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2954** option is used.
2955**
2956** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2957** must be either NULL or else pointers obtained from a prior
2958** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2959** not yet been released.
2960**
2961** The application must not read or write any part of
2962** a block of memory after it has been released using
2963** [sqlite3_free()] or [sqlite3_realloc()].
2964*/
2965SQLITE_API void *sqlite3_malloc(int);
2966SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
2967SQLITE_API void *sqlite3_realloc(void*, int);
2968SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
2969SQLITE_API void sqlite3_free(void*);
2970SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
2971
2972/*
2973** CAPI3REF: Memory Allocator Statistics
2974**
2975** SQLite provides these two interfaces for reporting on the status
2976** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2977** routines, which form the built-in memory allocation subsystem.
2978**
2979** ^The [sqlite3_memory_used()] routine returns the number of bytes
2980** of memory currently outstanding (malloced but not freed).
2981** ^The [sqlite3_memory_highwater()] routine returns the maximum
2982** value of [sqlite3_memory_used()] since the high-water mark
2983** was last reset. ^The values returned by [sqlite3_memory_used()] and
2984** [sqlite3_memory_highwater()] include any overhead
2985** added by SQLite in its implementation of [sqlite3_malloc()],
2986** but not overhead added by the any underlying system library
2987** routines that [sqlite3_malloc()] may call.
2988**
2989** ^The memory high-water mark is reset to the current value of
2990** [sqlite3_memory_used()] if and only if the parameter to
2991** [sqlite3_memory_highwater()] is true. ^The value returned
2992** by [sqlite3_memory_highwater(1)] is the high-water mark
2993** prior to the reset.
2994*/
2995SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
2996SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
2997
2998/*
2999** CAPI3REF: Pseudo-Random Number Generator
3000**
3001** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3002** select random [ROWID | ROWIDs] when inserting new records into a table that
3003** already uses the largest possible [ROWID]. The PRNG is also used for
3004** the built-in random() and randomblob() SQL functions. This interface allows
3005** applications to access the same PRNG for other purposes.
3006**
3007** ^A call to this routine stores N bytes of randomness into buffer P.
3008** ^The P parameter can be a NULL pointer.
3009**
3010** ^If this routine has not been previously called or if the previous
3011** call had N less than one or a NULL pointer for P, then the PRNG is
3012** seeded using randomness obtained from the xRandomness method of
3013** the default [sqlite3_vfs] object.
3014** ^If the previous call to this routine had an N of 1 or more and a
3015** non-NULL P then the pseudo-randomness is generated
3016** internally and without recourse to the [sqlite3_vfs] xRandomness
3017** method.
3018*/
3019SQLITE_API void sqlite3_randomness(int N, void *P);
3020
3021/*
3022** CAPI3REF: Compile-Time Authorization Callbacks
3023** METHOD: sqlite3
3024** KEYWORDS: {authorizer callback}
3025**
3026** ^This routine registers an authorizer callback with a particular
3027** [database connection], supplied in the first argument.
3028** ^The authorizer callback is invoked as SQL statements are being compiled
3029** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3030** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3031** and [sqlite3_prepare16_v3()]. ^At various
3032** points during the compilation process, as logic is being created
3033** to perform various actions, the authorizer callback is invoked to
3034** see if those actions are allowed. ^The authorizer callback should
3035** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3036** specific action but allow the SQL statement to continue to be
3037** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3038** rejected with an error. ^If the authorizer callback returns
3039** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3040** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3041** the authorizer will fail with an error message.
3042**
3043** When the callback returns [SQLITE_OK], that means the operation
3044** requested is ok. ^When the callback returns [SQLITE_DENY], the
3045** [sqlite3_prepare_v2()] or equivalent call that triggered the
3046** authorizer will fail with an error message explaining that
3047** access is denied.
3048**
3049** ^The first parameter to the authorizer callback is a copy of the third
3050** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3051** to the callback is an integer [SQLITE_COPY | action code] that specifies
3052** the particular action to be authorized. ^The third through sixth parameters
3053** to the callback are either NULL pointers or zero-terminated strings
3054** that contain additional details about the action to be authorized.
3055** Applications must always be prepared to encounter a NULL pointer in any
3056** of the third through the sixth parameters of the authorization callback.
3057**
3058** ^If the action code is [SQLITE_READ]
3059** and the callback returns [SQLITE_IGNORE] then the
3060** [prepared statement] statement is constructed to substitute
3061** a NULL value in place of the table column that would have
3062** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3063** return can be used to deny an untrusted user access to individual
3064** columns of a table.
3065** ^When a table is referenced by a [SELECT] but no column values are
3066** extracted from that table (for example in a query like
3067** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3068** is invoked once for that table with a column name that is an empty string.
3069** ^If the action code is [SQLITE_DELETE] and the callback returns
3070** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3071** [truncate optimization] is disabled and all rows are deleted individually.
3072**
3073** An authorizer is used when [sqlite3_prepare | preparing]
3074** SQL statements from an untrusted source, to ensure that the SQL statements
3075** do not try to access data they are not allowed to see, or that they do not
3076** try to execute malicious statements that damage the database. For
3077** example, an application may allow a user to enter arbitrary
3078** SQL queries for evaluation by a database. But the application does
3079** not want the user to be able to make arbitrary changes to the
3080** database. An authorizer could then be put in place while the
3081** user-entered SQL is being [sqlite3_prepare | prepared] that
3082** disallows everything except [SELECT] statements.
3083**
3084** Applications that need to process SQL from untrusted sources
3085** might also consider lowering resource limits using [sqlite3_limit()]
3086** and limiting database size using the [max_page_count] [PRAGMA]
3087** in addition to using an authorizer.
3088**
3089** ^(Only a single authorizer can be in place on a database connection
3090** at a time. Each call to sqlite3_set_authorizer overrides the
3091** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3092** The authorizer is disabled by default.
3093**
3094** The authorizer callback must not do anything that will modify
3095** the database connection that invoked the authorizer callback.
3096** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3097** database connections for the meaning of "modify" in this paragraph.
3098**
3099** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3100** statement might be re-prepared during [sqlite3_step()] due to a
3101** schema change. Hence, the application should ensure that the
3102** correct authorizer callback remains in place during the [sqlite3_step()].
3103**
3104** ^Note that the authorizer callback is invoked only during
3105** [sqlite3_prepare()] or its variants. Authorization is not
3106** performed during statement evaluation in [sqlite3_step()], unless
3107** as stated in the previous paragraph, sqlite3_step() invokes
3108** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3109*/
3110SQLITE_API int sqlite3_set_authorizer(
3111 sqlite3*,
3112 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3113 void *pUserData
3114);
3115
3116/*
3117** CAPI3REF: Authorizer Return Codes
3118**
3119** The [sqlite3_set_authorizer | authorizer callback function] must
3120** return either [SQLITE_OK] or one of these two constants in order
3121** to signal SQLite whether or not the action is permitted. See the
3122** [sqlite3_set_authorizer | authorizer documentation] for additional
3123** information.
3124**
3125** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3126** returned from the [sqlite3_vtab_on_conflict()] interface.
3127*/
3128#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3129#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3130
3131/*
3132** CAPI3REF: Authorizer Action Codes
3133**
3134** The [sqlite3_set_authorizer()] interface registers a callback function
3135** that is invoked to authorize certain SQL statement actions. The
3136** second parameter to the callback is an integer code that specifies
3137** what action is being authorized. These are the integer action codes that
3138** the authorizer callback may be passed.
3139**
3140** These action code values signify what kind of operation is to be
3141** authorized. The 3rd and 4th parameters to the authorization
3142** callback function will be parameters or NULL depending on which of these
3143** codes is used as the second parameter. ^(The 5th parameter to the
3144** authorizer callback is the name of the database ("main", "temp",
3145** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3146** is the name of the inner-most trigger or view that is responsible for
3147** the access attempt or NULL if this access attempt is directly from
3148** top-level SQL code.
3149*/
3150/******************************************* 3rd ************ 4th ***********/
3151#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3152#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3153#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3154#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3155#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3156#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3157#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3158#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3159#define SQLITE_DELETE 9 /* Table Name NULL */
3160#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3161#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3162#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3163#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3164#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3165#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3166#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3167#define SQLITE_DROP_VIEW 17 /* View Name NULL */
3168#define SQLITE_INSERT 18 /* Table Name NULL */
3169#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3170#define SQLITE_READ 20 /* Table Name Column Name */
3171#define SQLITE_SELECT 21 /* NULL NULL */
3172#define SQLITE_TRANSACTION 22 /* Operation NULL */
3173#define SQLITE_UPDATE 23 /* Table Name Column Name */
3174#define SQLITE_ATTACH 24 /* Filename NULL */
3175#define SQLITE_DETACH 25 /* Database Name NULL */
3176#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3177#define SQLITE_REINDEX 27 /* Index Name NULL */
3178#define SQLITE_ANALYZE 28 /* Table Name NULL */
3179#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3180#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3181#define SQLITE_FUNCTION 31 /* NULL Function Name */
3182#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3183#define SQLITE_COPY 0 /* No longer used */
3184#define SQLITE_RECURSIVE 33 /* NULL NULL */
3185
3186/*
3187** CAPI3REF: Tracing And Profiling Functions
3188** METHOD: sqlite3
3189**
3190** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3191** instead of the routines described here.
3192**
3193** These routines register callback functions that can be used for
3194** tracing and profiling the execution of SQL statements.
3195**
3196** ^The callback function registered by sqlite3_trace() is invoked at
3197** various times when an SQL statement is being run by [sqlite3_step()].
3198** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3199** SQL statement text as the statement first begins executing.
3200** ^(Additional sqlite3_trace() callbacks might occur
3201** as each triggered subprogram is entered. The callbacks for triggers
3202** contain a UTF-8 SQL comment that identifies the trigger.)^
3203**
3204** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3205** the length of [bound parameter] expansion in the output of sqlite3_trace().
3206**
3207** ^The callback function registered by sqlite3_profile() is invoked
3208** as each SQL statement finishes. ^The profile callback contains
3209** the original statement text and an estimate of wall-clock time
3210** of how long that statement took to run. ^The profile callback
3211** time is in units of nanoseconds, however the current implementation
3212** is only capable of millisecond resolution so the six least significant
3213** digits in the time are meaningless. Future versions of SQLite
3214** might provide greater resolution on the profiler callback. Invoking
3215** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3216** profile callback.
3217*/
3218SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3219 void(*xTrace)(void*,const char*), void*);
3220SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3221 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3222
3223/*
3224** CAPI3REF: SQL Trace Event Codes
3225** KEYWORDS: SQLITE_TRACE
3226**
3227** These constants identify classes of events that can be monitored
3228** using the [sqlite3_trace_v2()] tracing logic. The M argument
3229** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3230** the following constants. ^The first argument to the trace callback
3231** is one of the following constants.
3232**
3233** New tracing constants may be added in future releases.
3234**
3235** ^A trace callback has four arguments: xCallback(T,C,P,X).
3236** ^The T argument is one of the integer type codes above.
3237** ^The C argument is a copy of the context pointer passed in as the
3238** fourth argument to [sqlite3_trace_v2()].
3239** The P and X arguments are pointers whose meanings depend on T.
3240**
3241** <dl>
3242** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3243** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3244** first begins running and possibly at other times during the
3245** execution of the prepared statement, such as at the start of each
3246** trigger subprogram. ^The P argument is a pointer to the
3247** [prepared statement]. ^The X argument is a pointer to a string which
3248** is the unexpanded SQL text of the prepared statement or an SQL comment
3249** that indicates the invocation of a trigger. ^The callback can compute
3250** the same text that would have been returned by the legacy [sqlite3_trace()]
3251** interface by using the X argument when X begins with "--" and invoking
3252** [sqlite3_expanded_sql(P)] otherwise.
3253**
3254** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3255** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3256** information as is provided by the [sqlite3_profile()] callback.
3257** ^The P argument is a pointer to the [prepared statement] and the
3258** X argument points to a 64-bit integer which is the estimated of
3259** the number of nanosecond that the prepared statement took to run.
3260** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3261**
3262** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3263** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3264** statement generates a single row of result.
3265** ^The P argument is a pointer to the [prepared statement] and the
3266** X argument is unused.
3267**
3268** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3269** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3270** connection closes.
3271** ^The P argument is a pointer to the [database connection] object
3272** and the X argument is unused.
3273** </dl>
3274*/
3275#define SQLITE_TRACE_STMT 0x01
3276#define SQLITE_TRACE_PROFILE 0x02
3277#define SQLITE_TRACE_ROW 0x04
3278#define SQLITE_TRACE_CLOSE 0x08
3279
3280/*
3281** CAPI3REF: SQL Trace Hook
3282** METHOD: sqlite3
3283**
3284** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3285** function X against [database connection] D, using property mask M
3286** and context pointer P. ^If the X callback is
3287** NULL or if the M mask is zero, then tracing is disabled. The
3288** M argument should be the bitwise OR-ed combination of
3289** zero or more [SQLITE_TRACE] constants.
3290**
3291** ^Each call to either sqlite3_trace() or sqlite3_trace_v2() overrides
3292** (cancels) any prior calls to sqlite3_trace() or sqlite3_trace_v2().
3293**
3294** ^The X callback is invoked whenever any of the events identified by
3295** mask M occur. ^The integer return value from the callback is currently
3296** ignored, though this may change in future releases. Callback
3297** implementations should return zero to ensure future compatibility.
3298**
3299** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3300** ^The T argument is one of the [SQLITE_TRACE]
3301** constants to indicate why the callback was invoked.
3302** ^The C argument is a copy of the context pointer.
3303** The P and X arguments are pointers whose meanings depend on T.
3304**
3305** The sqlite3_trace_v2() interface is intended to replace the legacy
3306** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3307** are deprecated.
3308*/
3309SQLITE_API int sqlite3_trace_v2(
3310 sqlite3*,
3311 unsigned uMask,
3312 int(*xCallback)(unsigned,void*,void*,void*),
3313 void *pCtx
3314);
3315
3316/*
3317** CAPI3REF: Query Progress Callbacks
3318** METHOD: sqlite3
3319**
3320** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3321** function X to be invoked periodically during long running calls to
3322** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
3323** database connection D. An example use for this
3324** interface is to keep a GUI updated during a large query.
3325**
3326** ^The parameter P is passed through as the only parameter to the
3327** callback function X. ^The parameter N is the approximate number of
3328** [virtual machine instructions] that are evaluated between successive
3329** invocations of the callback X. ^If N is less than one then the progress
3330** handler is disabled.
3331**
3332** ^Only a single progress handler may be defined at one time per
3333** [database connection]; setting a new progress handler cancels the
3334** old one. ^Setting parameter X to NULL disables the progress handler.
3335** ^The progress handler is also disabled by setting N to a value less
3336** than 1.
3337**
3338** ^If the progress callback returns non-zero, the operation is
3339** interrupted. This feature can be used to implement a
3340** "Cancel" button on a GUI progress dialog box.
3341**
3342** The progress handler callback must not do anything that will modify
3343** the database connection that invoked the progress handler.
3344** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3345** database connections for the meaning of "modify" in this paragraph.
3346**
3347*/
3348SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3349
3350/*
3351** CAPI3REF: Opening A New Database Connection
3352** CONSTRUCTOR: sqlite3
3353**
3354** ^These routines open an SQLite database file as specified by the
3355** filename argument. ^The filename argument is interpreted as UTF-8 for
3356** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3357** order for sqlite3_open16(). ^(A [database connection] handle is usually
3358** returned in *ppDb, even if an error occurs. The only exception is that
3359** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3360** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3361** object.)^ ^(If the database is opened (and/or created) successfully, then
3362** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3363** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3364** an English language description of the error following a failure of any
3365** of the sqlite3_open() routines.
3366**
3367** ^The default encoding will be UTF-8 for databases created using
3368** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3369** created using sqlite3_open16() will be UTF-16 in the native byte order.
3370**
3371** Whether or not an error occurs when it is opened, resources
3372** associated with the [database connection] handle should be released by
3373** passing it to [sqlite3_close()] when it is no longer required.
3374**
3375** The sqlite3_open_v2() interface works like sqlite3_open()
3376** except that it accepts two additional parameters for additional control
3377** over the new database connection. ^(The flags parameter to
3378** sqlite3_open_v2() must include, at a minimum, one of the following
3379** three flag combinations:)^
3380**
3381** <dl>
3382** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3383** <dd>The database is opened in read-only mode. If the database does not
3384** already exist, an error is returned.</dd>)^
3385**
3386** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3387** <dd>The database is opened for reading and writing if possible, or reading
3388** only if the file is write protected by the operating system. In either
3389** case the database must already exist, otherwise an error is returned.</dd>)^
3390**
3391** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3392** <dd>The database is opened for reading and writing, and is created if
3393** it does not already exist. This is the behavior that is always used for
3394** sqlite3_open() and sqlite3_open16().</dd>)^
3395** </dl>
3396**
3397** In addition to the required flags, the following optional flags are
3398** also supported:
3399**
3400** <dl>
3401** ^(<dt>[SQLITE_OPEN_URI]</dt>
3402** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3403**
3404** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3405** <dd>The database will be opened as an in-memory database. The database
3406** is named by the "filename" argument for the purposes of cache-sharing,
3407** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3408** </dd>)^
3409**
3410** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3411** <dd>The new database connection will use the "multi-thread"
3412** [threading mode].)^ This means that separate threads are allowed
3413** to use SQLite at the same time, as long as each thread is using
3414** a different [database connection].
3415**
3416** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3417** <dd>The new database connection will use the "serialized"
3418** [threading mode].)^ This means the multiple threads can safely
3419** attempt to use the same database connection at the same time.
3420** (Mutexes will block any actual concurrency, but in this mode
3421** there is no harm in trying.)
3422**
3423** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3424** <dd>The database is opened [shared cache] enabled, overriding
3425** the default shared cache setting provided by
3426** [sqlite3_enable_shared_cache()].)^
3427**
3428** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3429** <dd>The database is opened [shared cache] disabled, overriding
3430** the default shared cache setting provided by
3431** [sqlite3_enable_shared_cache()].)^
3432**
3433** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3434** <dd>The database connection comes up in "extended result code mode".
3435** In other words, the database behaves has if
3436** [sqlite3_extended_result_codes(db,1)] where called on the database
3437** connection as soon as the connection is created. In addition to setting
3438** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3439** to return an extended result code.</dd>
3440**
3441** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3442** <dd>The database filename is not allowed to be a symbolic link</dd>
3443** </dl>)^
3444**
3445** If the 3rd parameter to sqlite3_open_v2() is not one of the
3446** required combinations shown above optionally combined with other
3447** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3448** then the behavior is undefined. Historic versions of SQLite
3449** have silently ignored surplus bits in the flags parameter to
3450** sqlite3_open_v2(), however that behavior might not be carried through
3451** into future versions of SQLite and so applications should not rely
3452** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3453** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3454** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3455** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3456** by sqlite3_open_v2().
3457**
3458** ^The fourth parameter to sqlite3_open_v2() is the name of the
3459** [sqlite3_vfs] object that defines the operating system interface that
3460** the new database connection should use. ^If the fourth parameter is
3461** a NULL pointer then the default [sqlite3_vfs] object is used.
3462**
3463** ^If the filename is ":memory:", then a private, temporary in-memory database
3464** is created for the connection. ^This in-memory database will vanish when
3465** the database connection is closed. Future versions of SQLite might
3466** make use of additional special filenames that begin with the ":" character.
3467** It is recommended that when a database filename actually does begin with
3468** a ":" character you should prefix the filename with a pathname such as
3469** "./" to avoid ambiguity.
3470**
3471** ^If the filename is an empty string, then a private, temporary
3472** on-disk database will be created. ^This private database will be
3473** automatically deleted as soon as the database connection is closed.
3474**
3475** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3476**
3477** ^If [URI filename] interpretation is enabled, and the filename argument
3478** begins with "file:", then the filename is interpreted as a URI. ^URI
3479** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3480** set in the third argument to sqlite3_open_v2(), or if it has
3481** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3482** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3483** URI filename interpretation is turned off
3484** by default, but future releases of SQLite might enable URI filename
3485** interpretation by default. See "[URI filenames]" for additional
3486** information.
3487**
3488** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3489** authority, then it must be either an empty string or the string
3490** "localhost". ^If the authority is not an empty string or "localhost", an
3491** error is returned to the caller. ^The fragment component of a URI, if
3492** present, is ignored.
3493**
3494** ^SQLite uses the path component of the URI as the name of the disk file
3495** which contains the database. ^If the path begins with a '/' character,
3496** then it is interpreted as an absolute path. ^If the path does not begin
3497** with a '/' (meaning that the authority section is omitted from the URI)
3498** then the path is interpreted as a relative path.
3499** ^(On windows, the first component of an absolute path
3500** is a drive specification (e.g. "C:").)^
3501**
3502** [[core URI query parameters]]
3503** The query component of a URI may contain parameters that are interpreted
3504** either by SQLite itself, or by a [VFS | custom VFS implementation].
3505** SQLite and its built-in [VFSes] interpret the
3506** following query parameters:
3507**
3508** <ul>
3509** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3510** a VFS object that provides the operating system interface that should
3511** be used to access the database file on disk. ^If this option is set to
3512** an empty string the default VFS object is used. ^Specifying an unknown
3513** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3514** present, then the VFS specified by the option takes precedence over
3515** the value passed as the fourth parameter to sqlite3_open_v2().
3516**
3517** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3518** "rwc", or "memory". Attempting to set it to any other value is
3519** an error)^.
3520** ^If "ro" is specified, then the database is opened for read-only
3521** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3522** third argument to sqlite3_open_v2(). ^If the mode option is set to
3523** "rw", then the database is opened for read-write (but not create)
3524** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3525** been set. ^Value "rwc" is equivalent to setting both
3526** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3527** set to "memory" then a pure [in-memory database] that never reads
3528** or writes from disk is used. ^It is an error to specify a value for
3529** the mode parameter that is less restrictive than that specified by
3530** the flags passed in the third parameter to sqlite3_open_v2().
3531**
3532** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3533** "private". ^Setting it to "shared" is equivalent to setting the
3534** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3535** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3536** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3537** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3538** a URI filename, its value overrides any behavior requested by setting
3539** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3540**
3541** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3542** [powersafe overwrite] property does or does not apply to the
3543** storage media on which the database file resides.
3544**
3545** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3546** which if set disables file locking in rollback journal modes. This
3547** is useful for accessing a database on a filesystem that does not
3548** support locking. Caution: Database corruption might result if two
3549** or more processes write to the same database and any one of those
3550** processes uses nolock=1.
3551**
3552** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3553** parameter that indicates that the database file is stored on
3554** read-only media. ^When immutable is set, SQLite assumes that the
3555** database file cannot be changed, even by a process with higher
3556** privilege, and so the database is opened read-only and all locking
3557** and change detection is disabled. Caution: Setting the immutable
3558** property on a database file that does in fact change can result
3559** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3560** See also: [SQLITE_IOCAP_IMMUTABLE].
3561**
3562** </ul>
3563**
3564** ^Specifying an unknown parameter in the query component of a URI is not an
3565** error. Future versions of SQLite might understand additional query
3566** parameters. See "[query parameters with special meaning to SQLite]" for
3567** additional information.
3568**
3569** [[URI filename examples]] <h3>URI filename examples</h3>
3570**
3571** <table border="1" align=center cellpadding=5>
3572** <tr><th> URI filenames <th> Results
3573** <tr><td> file:data.db <td>
3574** Open the file "data.db" in the current directory.
3575** <tr><td> file:/home/fred/data.db<br>
3576** file:///home/fred/data.db <br>
3577** file://localhost/home/fred/data.db <br> <td>
3578** Open the database file "/home/fred/data.db".
3579** <tr><td> file://darkstar/home/fred/data.db <td>
3580** An error. "darkstar" is not a recognized authority.
3581** <tr><td style="white-space:nowrap">
3582** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3583** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3584** C:. Note that the %20 escaping in this example is not strictly
3585** necessary - space characters can be used literally
3586** in URI filenames.
3587** <tr><td> file:data.db?mode=ro&cache=private <td>
3588** Open file "data.db" in the current directory for read-only access.
3589** Regardless of whether or not shared-cache mode is enabled by
3590** default, use a private cache.
3591** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3592** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3593** that uses dot-files in place of posix advisory locking.
3594** <tr><td> file:data.db?mode=readonly <td>
3595** An error. "readonly" is not a valid option for the "mode" parameter.
3596** Use "ro" instead: "file:data.db?mode=ro".
3597** </table>
3598**
3599** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3600** query components of a URI. A hexadecimal escape sequence consists of a
3601** percent sign - "%" - followed by exactly two hexadecimal digits
3602** specifying an octet value. ^Before the path or query components of a
3603** URI filename are interpreted, they are encoded using UTF-8 and all
3604** hexadecimal escape sequences replaced by a single byte containing the
3605** corresponding octet. If this process generates an invalid UTF-8 encoding,
3606** the results are undefined.
3607**
3608** <b>Note to Windows users:</b> The encoding used for the filename argument
3609** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3610** codepage is currently defined. Filenames containing international
3611** characters must be converted to UTF-8 prior to passing them into
3612** sqlite3_open() or sqlite3_open_v2().
3613**
3614** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3615** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3616** features that require the use of temporary files may fail.
3617**
3618** See also: [sqlite3_temp_directory]
3619*/
3620SQLITE_API int sqlite3_open(
3621 const char *filename, /* Database filename (UTF-8) */
3622 sqlite3 **ppDb /* OUT: SQLite db handle */
3623);
3624SQLITE_API int sqlite3_open16(
3625 const void *filename, /* Database filename (UTF-16) */
3626 sqlite3 **ppDb /* OUT: SQLite db handle */
3627);
3628SQLITE_API int sqlite3_open_v2(
3629 const char *filename, /* Database filename (UTF-8) */
3630 sqlite3 **ppDb, /* OUT: SQLite db handle */
3631 int flags, /* Flags */
3632 const char *zVfs /* Name of VFS module to use */
3633);
3634
3635/*
3636** CAPI3REF: Obtain Values For URI Parameters
3637**
3638** These are utility routines, useful to [VFS|custom VFS implementations],
3639** that check if a database file was a URI that contained a specific query
3640** parameter, and if so obtains the value of that query parameter.
3641**
3642** The first parameter to these interfaces (hereafter referred to
3643** as F) must be one of:
3644** <ul>
3645** <li> A database filename pointer created by the SQLite core and
3646** passed into the xOpen() method of a VFS implemention, or
3647** <li> A filename obtained from [sqlite3_db_filename()], or
3648** <li> A new filename constructed using [sqlite3_create_filename()].
3649** </ul>
3650** If the F parameter is not one of the above, then the behavior is
3651** undefined and probably undesirable. Older versions of SQLite were
3652** more tolerant of invalid F parameters than newer versions.
3653**
3654** If F is a suitable filename (as described in the previous paragraph)
3655** and if P is the name of the query parameter, then
3656** sqlite3_uri_parameter(F,P) returns the value of the P
3657** parameter if it exists or a NULL pointer if P does not appear as a
3658** query parameter on F. If P is a query parameter of F and it
3659** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3660** a pointer to an empty string.
3661**
3662** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3663** parameter and returns true (1) or false (0) according to the value
3664** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3665** value of query parameter P is one of "yes", "true", or "on" in any
3666** case or if the value begins with a non-zero number. The
3667** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3668** query parameter P is one of "no", "false", or "off" in any case or
3669** if the value begins with a numeric zero. If P is not a query
3670** parameter on F or if the value of P does not match any of the
3671** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3672**
3673** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3674** 64-bit signed integer and returns that integer, or D if P does not
3675** exist. If the value of P is something other than an integer, then
3676** zero is returned.
3677**
3678** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3679** the value) of the N-th query parameter for filename F, or a NULL
3680** pointer if N is less than zero or greater than the number of query
3681** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3682** the name of the first query parameter, 1 for the second parameter, and
3683** so forth.
3684**
3685** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3686** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3687** is not a database file pathname pointer that the SQLite core passed
3688** into the xOpen VFS method, then the behavior of this routine is undefined
3689** and probably undesirable.
3690**
3691** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3692** parameter can also be the name of a rollback journal file or WAL file
3693** in addition to the main database file. Prior to version 3.31.0, these
3694** routines would only work if F was the name of the main database file.
3695** When the F parameter is the name of the rollback journal or WAL file,
3696** it has access to all the same query parameters as were found on the
3697** main database file.
3698**
3699** See the [URI filename] documentation for additional information.
3700*/
3701SQLITE_API const char *sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3702SQLITE_API int sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3703SQLITE_API sqlite3_int64 sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3704SQLITE_API const char *sqlite3_uri_key(const char *zFilename, int N);
3705
3706/*
3707** CAPI3REF: Translate filenames
3708**
3709** These routines are available to [VFS|custom VFS implementations] for
3710** translating filenames between the main database file, the journal file,
3711** and the WAL file.
3712**
3713** If F is the name of an sqlite database file, journal file, or WAL file
3714** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3715** returns the name of the corresponding database file.
3716**
3717** If F is the name of an sqlite database file, journal file, or WAL file
3718** passed by the SQLite core into the VFS, or if F is a database filename
3719** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3720** returns the name of the corresponding rollback journal file.
3721**
3722** If F is the name of an sqlite database file, journal file, or WAL file
3723** that was passed by the SQLite core into the VFS, or if F is a database
3724** filename obtained from [sqlite3_db_filename()], then
3725** sqlite3_filename_wal(F) returns the name of the corresponding
3726** WAL file.
3727**
3728** In all of the above, if F is not the name of a database, journal or WAL
3729** filename passed into the VFS from the SQLite core and F is not the
3730** return value from [sqlite3_db_filename()], then the result is
3731** undefined and is likely a memory access violation.
3732*/
3733SQLITE_API const char *sqlite3_filename_database(const char*);
3734SQLITE_API const char *sqlite3_filename_journal(const char*);
3735SQLITE_API const char *sqlite3_filename_wal(const char*);
3736
3737/*
3738** CAPI3REF: Database File Corresponding To A Journal
3739**
3740** ^If X is the name of a rollback or WAL-mode journal file that is
3741** passed into the xOpen method of [sqlite3_vfs], then
3742** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3743** object that represents the main database file.
3744**
3745** This routine is intended for use in custom [VFS] implementations
3746** only. It is not a general-purpose interface.
3747** The argument sqlite3_file_object(X) must be a filename pointer that
3748** has been passed into [sqlite3_vfs].xOpen method where the
3749** flags parameter to xOpen contains one of the bits
3750** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3751** of this routine results in undefined and probably undesirable
3752** behavior.
3753*/
3754SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3755
3756/*
3757** CAPI3REF: Create and Destroy VFS Filenames
3758**
3759** These interfces are provided for use by [VFS shim] implementations and
3760** are not useful outside of that context.
3761**
3762** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3763** database filename D with corresponding journal file J and WAL file W and
3764** with N URI parameters key/values pairs in the array P. The result from
3765** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3766** is safe to pass to routines like:
3767** <ul>
3768** <li> [sqlite3_uri_parameter()],
3769** <li> [sqlite3_uri_boolean()],
3770** <li> [sqlite3_uri_int64()],
3771** <li> [sqlite3_uri_key()],
3772** <li> [sqlite3_filename_database()],
3773** <li> [sqlite3_filename_journal()], or
3774** <li> [sqlite3_filename_wal()].
3775** </ul>
3776** If a memory allocation error occurs, sqlite3_create_filename() might
3777** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3778** must be released by a corresponding call to sqlite3_free_filename(Y).
3779**
3780** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3781** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3782** to a key and value for a query parameter. The P parameter may be a NULL
3783** pointer if N is zero. None of the 2*N pointers in the P array may be
3784** NULL pointers and key pointers should not be empty strings.
3785** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3786** be NULL pointers, though they can be empty strings.
3787**
3788** The sqlite3_free_filename(Y) routine releases a memory allocation
3789** previously obtained from sqlite3_create_filename(). Invoking
3790** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3791**
3792** If the Y parameter to sqlite3_free_filename(Y) is anything other
3793** than a NULL pointer or a pointer previously acquired from
3794** sqlite3_create_filename(), then bad things such as heap
3795** corruption or segfaults may occur. The value Y should not be
3796** used again after sqlite3_free_filename(Y) has been called. This means
3797** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3798** then the corresponding [sqlite3_module.xClose() method should also be
3799** invoked prior to calling sqlite3_free_filename(Y).
3800*/
3801SQLITE_API char *sqlite3_create_filename(
3802 const char *zDatabase,
3803 const char *zJournal,
3804 const char *zWal,
3805 int nParam,
3806 const char **azParam
3807);
3808SQLITE_API void sqlite3_free_filename(char*);
3809
3810/*
3811** CAPI3REF: Error Codes And Messages
3812** METHOD: sqlite3
3813**
3814** ^If the most recent sqlite3_* API call associated with
3815** [database connection] D failed, then the sqlite3_errcode(D) interface
3816** returns the numeric [result code] or [extended result code] for that
3817** API call.
3818** ^The sqlite3_extended_errcode()
3819** interface is the same except that it always returns the
3820** [extended result code] even when extended result codes are
3821** disabled.
3822**
3823** The values returned by sqlite3_errcode() and/or
3824** sqlite3_extended_errcode() might change with each API call.
3825** Except, there are some interfaces that are guaranteed to never
3826** change the value of the error code. The error-code preserving
3827** interfaces include the following:
3828**
3829** <ul>
3830** <li> sqlite3_errcode()
3831** <li> sqlite3_extended_errcode()
3832** <li> sqlite3_errmsg()
3833** <li> sqlite3_errmsg16()
3834** <li> sqlite3_error_offset()
3835** </ul>
3836**
3837** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3838** text that describes the error, as either UTF-8 or UTF-16 respectively.
3839** ^(Memory to hold the error message string is managed internally.
3840** The application does not need to worry about freeing the result.
3841** However, the error string might be overwritten or deallocated by
3842** subsequent calls to other SQLite interface functions.)^
3843**
3844** ^The sqlite3_errstr() interface returns the English-language text
3845** that describes the [result code], as UTF-8.
3846** ^(Memory to hold the error message string is managed internally
3847** and must not be freed by the application)^.
3848**
3849** ^If the most recent error references a specific token in the input
3850** SQL, the sqlite3_error_offset() interface returns the byte offset
3851** of the start of that token. ^The byte offset returned by
3852** sqlite3_error_offset() assumes that the input SQL is UTF8.
3853** ^If the most recent error does not reference a specific token in the input
3854** SQL, then the sqlite3_error_offset() function returns -1.
3855**
3856** When the serialized [threading mode] is in use, it might be the
3857** case that a second error occurs on a separate thread in between
3858** the time of the first error and the call to these interfaces.
3859** When that happens, the second error will be reported since these
3860** interfaces always report the most recent result. To avoid
3861** this, each thread can obtain exclusive use of the [database connection] D
3862** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3863** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3864** all calls to the interfaces listed here are completed.
3865**
3866** If an interface fails with SQLITE_MISUSE, that means the interface
3867** was invoked incorrectly by the application. In that case, the
3868** error code and message may or may not be set.
3869*/
3870SQLITE_API int sqlite3_errcode(sqlite3 *db);
3871SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
3872SQLITE_API const char *sqlite3_errmsg(sqlite3*);
3873SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
3874SQLITE_API const char *sqlite3_errstr(int);
3875SQLITE_API int sqlite3_error_offset(sqlite3 *db);
3876
3877/*
3878** CAPI3REF: Prepared Statement Object
3879** KEYWORDS: {prepared statement} {prepared statements}
3880**
3881** An instance of this object represents a single SQL statement that
3882** has been compiled into binary form and is ready to be evaluated.
3883**
3884** Think of each SQL statement as a separate computer program. The
3885** original SQL text is source code. A prepared statement object
3886** is the compiled object code. All SQL must be converted into a
3887** prepared statement before it can be run.
3888**
3889** The life-cycle of a prepared statement object usually goes like this:
3890**
3891** <ol>
3892** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3893** <li> Bind values to [parameters] using the sqlite3_bind_*()
3894** interfaces.
3895** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3896** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3897** to step 2. Do this zero or more times.
3898** <li> Destroy the object using [sqlite3_finalize()].
3899** </ol>
3900*/
3901typedef struct sqlite3_stmt sqlite3_stmt;
3902
3903/*
3904** CAPI3REF: Run-time Limits
3905** METHOD: sqlite3
3906**
3907** ^(This interface allows the size of various constructs to be limited
3908** on a connection by connection basis. The first parameter is the
3909** [database connection] whose limit is to be set or queried. The
3910** second parameter is one of the [limit categories] that define a
3911** class of constructs to be size limited. The third parameter is the
3912** new limit for that construct.)^
3913**
3914** ^If the new limit is a negative number, the limit is unchanged.
3915** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3916** [limits | hard upper bound]
3917** set at compile-time by a C preprocessor macro called
3918** [limits | SQLITE_MAX_<i>NAME</i>].
3919** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3920** ^Attempts to increase a limit above its hard upper bound are
3921** silently truncated to the hard upper bound.
3922**
3923** ^Regardless of whether or not the limit was changed, the
3924** [sqlite3_limit()] interface returns the prior value of the limit.
3925** ^Hence, to find the current value of a limit without changing it,
3926** simply invoke this interface with the third parameter set to -1.
3927**
3928** Run-time limits are intended for use in applications that manage
3929** both their own internal database and also databases that are controlled
3930** by untrusted external sources. An example application might be a
3931** web browser that has its own databases for storing history and
3932** separate databases controlled by JavaScript applications downloaded
3933** off the Internet. The internal databases can be given the
3934** large, default limits. Databases managed by external sources can
3935** be given much smaller limits designed to prevent a denial of service
3936** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3937** interface to further control untrusted SQL. The size of the database
3938** created by an untrusted script can be contained using the
3939** [max_page_count] [PRAGMA].
3940**
3941** New run-time limit categories may be added in future releases.
3942*/
3943SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
3944
3945/*
3946** CAPI3REF: Run-Time Limit Categories
3947** KEYWORDS: {limit category} {*limit categories}
3948**
3949** These constants define various performance limits
3950** that can be lowered at run-time using [sqlite3_limit()].
3951** The synopsis of the meanings of the various limits is shown below.
3952** Additional information is available at [limits | Limits in SQLite].
3953**
3954** <dl>
3955** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3956** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3957**
3958** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3959** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3960**
3961** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3962** <dd>The maximum number of columns in a table definition or in the
3963** result set of a [SELECT] or the maximum number of columns in an index
3964** or in an ORDER BY or GROUP BY clause.</dd>)^
3965**
3966** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3967** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3968**
3969** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3970** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3971**
3972** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3973** <dd>The maximum number of instructions in a virtual machine program
3974** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
3975** the equivalent tries to allocate space for more than this many opcodes
3976** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
3977**
3978** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3979** <dd>The maximum number of arguments on a function.</dd>)^
3980**
3981** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3982** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3983**
3984** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3985** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3986** <dd>The maximum length of the pattern argument to the [LIKE] or
3987** [GLOB] operators.</dd>)^
3988**
3989** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3990** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3991** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3992**
3993** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3994** <dd>The maximum depth of recursion for triggers.</dd>)^
3995**
3996** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3997** <dd>The maximum number of auxiliary worker threads that a single
3998** [prepared statement] may start.</dd>)^
3999** </dl>
4000*/
4001#define SQLITE_LIMIT_LENGTH 0
4002#define SQLITE_LIMIT_SQL_LENGTH 1
4003#define SQLITE_LIMIT_COLUMN 2
4004#define SQLITE_LIMIT_EXPR_DEPTH 3
4005#define SQLITE_LIMIT_COMPOUND_SELECT 4
4006#define SQLITE_LIMIT_VDBE_OP 5
4007#define SQLITE_LIMIT_FUNCTION_ARG 6
4008#define SQLITE_LIMIT_ATTACHED 7
4009#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4010#define SQLITE_LIMIT_VARIABLE_NUMBER 9
4011#define SQLITE_LIMIT_TRIGGER_DEPTH 10
4012#define SQLITE_LIMIT_WORKER_THREADS 11
4013
4014/*
4015** CAPI3REF: Prepare Flags
4016**
4017** These constants define various flags that can be passed into
4018** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4019** [sqlite3_prepare16_v3()] interfaces.
4020**
4021** New flags may be added in future releases of SQLite.
4022**
4023** <dl>
4024** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4025** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4026** that the prepared statement will be retained for a long time and
4027** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4028** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4029** be used just once or at most a few times and then destroyed using
4030** [sqlite3_finalize()] relatively soon. The current implementation acts
4031** on this hint by avoiding the use of [lookaside memory] so as not to
4032** deplete the limited store of lookaside memory. Future versions of
4033** SQLite may act on this hint differently.
4034**
4035** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4036** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4037** to be required for any prepared statement that wanted to use the
4038** [sqlite3_normalized_sql()] interface. However, the
4039** [sqlite3_normalized_sql()] interface is now available to all
4040** prepared statements, regardless of whether or not they use this
4041** flag.
4042**
4043** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4044** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4045** to return an error (error code SQLITE_ERROR) if the statement uses
4046** any virtual tables.
4047** </dl>
4048*/
4049#define SQLITE_PREPARE_PERSISTENT 0x01
4050#define SQLITE_PREPARE_NORMALIZE 0x02
4051#define SQLITE_PREPARE_NO_VTAB 0x04
4052
4053/*
4054** CAPI3REF: Compiling An SQL Statement
4055** KEYWORDS: {SQL statement compiler}
4056** METHOD: sqlite3
4057** CONSTRUCTOR: sqlite3_stmt
4058**
4059** To execute an SQL statement, it must first be compiled into a byte-code
4060** program using one of these routines. Or, in other words, these routines
4061** are constructors for the [prepared statement] object.
4062**
4063** The preferred routine to use is [sqlite3_prepare_v2()]. The
4064** [sqlite3_prepare()] interface is legacy and should be avoided.
4065** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4066** for special purposes.
4067**
4068** The use of the UTF-8 interfaces is preferred, as SQLite currently
4069** does all parsing using UTF-8. The UTF-16 interfaces are provided
4070** as a convenience. The UTF-16 interfaces work by converting the
4071** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4072**
4073** The first argument, "db", is a [database connection] obtained from a
4074** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4075** [sqlite3_open16()]. The database connection must not have been closed.
4076**
4077** The second argument, "zSql", is the statement to be compiled, encoded
4078** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4079** and sqlite3_prepare_v3()
4080** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4081** and sqlite3_prepare16_v3() use UTF-16.
4082**
4083** ^If the nByte argument is negative, then zSql is read up to the
4084** first zero terminator. ^If nByte is positive, then it is the
4085** number of bytes read from zSql. ^If nByte is zero, then no prepared
4086** statement is generated.
4087** If the caller knows that the supplied string is nul-terminated, then
4088** there is a small performance advantage to passing an nByte parameter that
4089** is the number of bytes in the input string <i>including</i>
4090** the nul-terminator.
4091**
4092** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4093** past the end of the first SQL statement in zSql. These routines only
4094** compile the first statement in zSql, so *pzTail is left pointing to
4095** what remains uncompiled.
4096**
4097** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4098** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4099** to NULL. ^If the input text contains no SQL (if the input is an empty
4100** string or a comment) then *ppStmt is set to NULL.
4101** The calling procedure is responsible for deleting the compiled
4102** SQL statement using [sqlite3_finalize()] after it has finished with it.
4103** ppStmt may not be NULL.
4104**
4105** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4106** otherwise an [error code] is returned.
4107**
4108** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4109** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4110** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4111** are retained for backwards compatibility, but their use is discouraged.
4112** ^In the "vX" interfaces, the prepared statement
4113** that is returned (the [sqlite3_stmt] object) contains a copy of the
4114** original SQL text. This causes the [sqlite3_step()] interface to
4115** behave differently in three ways:
4116**
4117** <ol>
4118** <li>
4119** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4120** always used to do, [sqlite3_step()] will automatically recompile the SQL
4121** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4122** retries will occur before sqlite3_step() gives up and returns an error.
4123** </li>
4124**
4125** <li>
4126** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4127** [error codes] or [extended error codes]. ^The legacy behavior was that
4128** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4129** and the application would have to make a second call to [sqlite3_reset()]
4130** in order to find the underlying cause of the problem. With the "v2" prepare
4131** interfaces, the underlying reason for the error is returned immediately.
4132** </li>
4133**
4134** <li>
4135** ^If the specific value bound to a [parameter | host parameter] in the
4136** WHERE clause might influence the choice of query plan for a statement,
4137** then the statement will be automatically recompiled, as if there had been
4138** a schema change, on the first [sqlite3_step()] call following any change
4139** to the [sqlite3_bind_text | bindings] of that [parameter].
4140** ^The specific value of a WHERE-clause [parameter] might influence the
4141** choice of query plan if the parameter is the left-hand side of a [LIKE]
4142** or [GLOB] operator or if the parameter is compared to an indexed column
4143** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4144** </li>
4145** </ol>
4146**
4147** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4148** the extra prepFlags parameter, which is a bit array consisting of zero or
4149** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4150** sqlite3_prepare_v2() interface works exactly the same as
4151** sqlite3_prepare_v3() with a zero prepFlags parameter.
4152*/
4153SQLITE_API int sqlite3_prepare(
4154 sqlite3 *db, /* Database handle */
4155 const char *zSql, /* SQL statement, UTF-8 encoded */
4156 int nByte, /* Maximum length of zSql in bytes. */
4157 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4158 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4159);
4160SQLITE_API int sqlite3_prepare_v2(
4161 sqlite3 *db, /* Database handle */
4162 const char *zSql, /* SQL statement, UTF-8 encoded */
4163 int nByte, /* Maximum length of zSql in bytes. */
4164 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4165 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4166);
4167SQLITE_API int sqlite3_prepare_v3(
4168 sqlite3 *db, /* Database handle */
4169 const char *zSql, /* SQL statement, UTF-8 encoded */
4170 int nByte, /* Maximum length of zSql in bytes. */
4171 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4172 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4173 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4174);
4175SQLITE_API int sqlite3_prepare16(
4176 sqlite3 *db, /* Database handle */
4177 const void *zSql, /* SQL statement, UTF-16 encoded */
4178 int nByte, /* Maximum length of zSql in bytes. */
4179 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4180 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4181);
4182SQLITE_API int sqlite3_prepare16_v2(
4183 sqlite3 *db, /* Database handle */
4184 const void *zSql, /* SQL statement, UTF-16 encoded */
4185 int nByte, /* Maximum length of zSql in bytes. */
4186 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4187 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4188);
4189SQLITE_API int sqlite3_prepare16_v3(
4190 sqlite3 *db, /* Database handle */
4191 const void *zSql, /* SQL statement, UTF-16 encoded */
4192 int nByte, /* Maximum length of zSql in bytes. */
4193 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4194 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4195 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4196);
4197
4198/*
4199** CAPI3REF: Retrieving Statement SQL
4200** METHOD: sqlite3_stmt
4201**
4202** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4203** SQL text used to create [prepared statement] P if P was
4204** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4205** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4206** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4207** string containing the SQL text of prepared statement P with
4208** [bound parameters] expanded.
4209** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4210** string containing the normalized SQL text of prepared statement P. The
4211** semantics used to normalize a SQL statement are unspecified and subject
4212** to change. At a minimum, literal values will be replaced with suitable
4213** placeholders.
4214**
4215** ^(For example, if a prepared statement is created using the SQL
4216** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4217** and parameter :xyz is unbound, then sqlite3_sql() will return
4218** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4219** will return "SELECT 2345,NULL".)^
4220**
4221** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4222** is available to hold the result, or if the result would exceed the
4223** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4224**
4225** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4226** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4227** option causes sqlite3_expanded_sql() to always return NULL.
4228**
4229** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4230** are managed by SQLite and are automatically freed when the prepared
4231** statement is finalized.
4232** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4233** is obtained from [sqlite3_malloc()] and must be freed by the application
4234** by passing it to [sqlite3_free()].
4235**
4236** ^The sqlite3_normalized_sql() interface is only available if
4237** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4238*/
4239SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4240SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4241#ifdef SQLITE_ENABLE_NORMALIZE
4242SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4243#endif
4244
4245/*
4246** CAPI3REF: Determine If An SQL Statement Writes The Database
4247** METHOD: sqlite3_stmt
4248**
4249** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4250** and only if the [prepared statement] X makes no direct changes to
4251** the content of the database file.
4252**
4253** Note that [application-defined SQL functions] or
4254** [virtual tables] might change the database indirectly as a side effect.
4255** ^(For example, if an application defines a function "eval()" that
4256** calls [sqlite3_exec()], then the following SQL statement would
4257** change the database file through side-effects:
4258**
4259** <blockquote><pre>
4260** SELECT eval('DELETE FROM t1') FROM t2;
4261** </pre></blockquote>
4262**
4263** But because the [SELECT] statement does not change the database file
4264** directly, sqlite3_stmt_readonly() would still return true.)^
4265**
4266** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4267** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4268** since the statements themselves do not actually modify the database but
4269** rather they control the timing of when other statements modify the
4270** database. ^The [ATTACH] and [DETACH] statements also cause
4271** sqlite3_stmt_readonly() to return true since, while those statements
4272** change the configuration of a database connection, they do not make
4273** changes to the content of the database files on disk.
4274** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4275** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4276** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4277** sqlite3_stmt_readonly() returns false for those commands.
4278**
4279** ^This routine returns false if there is any possibility that the
4280** statement might change the database file. ^A false return does
4281** not guarantee that the statement will change the database file.
4282** ^For example, an UPDATE statement might have a WHERE clause that
4283** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4284** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4285** read-only no-op if the table already exists, but
4286** sqlite3_stmt_readonly() still returns false for such a statement.
4287**
4288** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4289** statement, then sqlite3_stmt_readonly(X) returns the same value as
4290** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4291*/
4292SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4293
4294/*
4295** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4296** METHOD: sqlite3_stmt
4297**
4298** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4299** prepared statement S is an EXPLAIN statement, or 2 if the
4300** statement S is an EXPLAIN QUERY PLAN.
4301** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4302** an ordinary statement or a NULL pointer.
4303*/
4304SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4305
4306/*
4307** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4308** METHOD: sqlite3_stmt
4309**
4310** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4311** [prepared statement] S has been stepped at least once using
4312** [sqlite3_step(S)] but has neither run to completion (returned
4313** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4314** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4315** interface returns false if S is a NULL pointer. If S is not a
4316** NULL pointer and is not a pointer to a valid [prepared statement]
4317** object, then the behavior is undefined and probably undesirable.
4318**
4319** This interface can be used in combination [sqlite3_next_stmt()]
4320** to locate all prepared statements associated with a database
4321** connection that are in need of being reset. This can be used,
4322** for example, in diagnostic routines to search for prepared
4323** statements that are holding a transaction open.
4324*/
4325SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4326
4327/*
4328** CAPI3REF: Dynamically Typed Value Object
4329** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4330**
4331** SQLite uses the sqlite3_value object to represent all values
4332** that can be stored in a database table. SQLite uses dynamic typing
4333** for the values it stores. ^Values stored in sqlite3_value objects
4334** can be integers, floating point values, strings, BLOBs, or NULL.
4335**
4336** An sqlite3_value object may be either "protected" or "unprotected".
4337** Some interfaces require a protected sqlite3_value. Other interfaces
4338** will accept either a protected or an unprotected sqlite3_value.
4339** Every interface that accepts sqlite3_value arguments specifies
4340** whether or not it requires a protected sqlite3_value. The
4341** [sqlite3_value_dup()] interface can be used to construct a new
4342** protected sqlite3_value from an unprotected sqlite3_value.
4343**
4344** The terms "protected" and "unprotected" refer to whether or not
4345** a mutex is held. An internal mutex is held for a protected
4346** sqlite3_value object but no mutex is held for an unprotected
4347** sqlite3_value object. If SQLite is compiled to be single-threaded
4348** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4349** or if SQLite is run in one of reduced mutex modes
4350** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4351** then there is no distinction between protected and unprotected
4352** sqlite3_value objects and they can be used interchangeably. However,
4353** for maximum code portability it is recommended that applications
4354** still make the distinction between protected and unprotected
4355** sqlite3_value objects even when not strictly required.
4356**
4357** ^The sqlite3_value objects that are passed as parameters into the
4358** implementation of [application-defined SQL functions] are protected.
4359** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4360** are protected.
4361** ^The sqlite3_value object returned by
4362** [sqlite3_column_value()] is unprotected.
4363** Unprotected sqlite3_value objects may only be used as arguments
4364** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4365** [sqlite3_value_dup()].
4366** The [sqlite3_value_blob | sqlite3_value_type()] family of
4367** interfaces require protected sqlite3_value objects.
4368*/
4369typedef struct sqlite3_value sqlite3_value;
4370
4371/*
4372** CAPI3REF: SQL Function Context Object
4373**
4374** The context in which an SQL function executes is stored in an
4375** sqlite3_context object. ^A pointer to an sqlite3_context object
4376** is always first parameter to [application-defined SQL functions].
4377** The application-defined SQL function implementation will pass this
4378** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4379** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4380** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4381** and/or [sqlite3_set_auxdata()].
4382*/
4383typedef struct sqlite3_context sqlite3_context;
4384
4385/*
4386** CAPI3REF: Binding Values To Prepared Statements
4387** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4388** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4389** METHOD: sqlite3_stmt
4390**
4391** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4392** literals may be replaced by a [parameter] that matches one of following
4393** templates:
4394**
4395** <ul>
4396** <li> ?
4397** <li> ?NNN
4398** <li> :VVV
4399** <li> @VVV
4400** <li> $VVV
4401** </ul>
4402**
4403** In the templates above, NNN represents an integer literal,
4404** and VVV represents an alphanumeric identifier.)^ ^The values of these
4405** parameters (also called "host parameter names" or "SQL parameters")
4406** can be set using the sqlite3_bind_*() routines defined here.
4407**
4408** ^The first argument to the sqlite3_bind_*() routines is always
4409** a pointer to the [sqlite3_stmt] object returned from
4410** [sqlite3_prepare_v2()] or its variants.
4411**
4412** ^The second argument is the index of the SQL parameter to be set.
4413** ^The leftmost SQL parameter has an index of 1. ^When the same named
4414** SQL parameter is used more than once, second and subsequent
4415** occurrences have the same index as the first occurrence.
4416** ^The index for named parameters can be looked up using the
4417** [sqlite3_bind_parameter_index()] API if desired. ^The index
4418** for "?NNN" parameters is the value of NNN.
4419** ^The NNN value must be between 1 and the [sqlite3_limit()]
4420** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4421**
4422** ^The third argument is the value to bind to the parameter.
4423** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4424** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4425** is ignored and the end result is the same as sqlite3_bind_null().
4426** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4427** it should be a pointer to well-formed UTF8 text.
4428** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4429** it should be a pointer to well-formed UTF16 text.
4430** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4431** it should be a pointer to a well-formed unicode string that is
4432** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4433** otherwise.
4434**
4435** [[byte-order determination rules]] ^The byte-order of
4436** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4437** found in first character, which is removed, or in the absence of a BOM
4438** the byte order is the native byte order of the host
4439** machine for sqlite3_bind_text16() or the byte order specified in
4440** the 6th parameter for sqlite3_bind_text64().)^
4441** ^If UTF16 input text contains invalid unicode
4442** characters, then SQLite might change those invalid characters
4443** into the unicode replacement character: U+FFFD.
4444**
4445** ^(In those routines that have a fourth argument, its value is the
4446** number of bytes in the parameter. To be clear: the value is the
4447** number of <u>bytes</u> in the value, not the number of characters.)^
4448** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4449** is negative, then the length of the string is
4450** the number of bytes up to the first zero terminator.
4451** If the fourth parameter to sqlite3_bind_blob() is negative, then
4452** the behavior is undefined.
4453** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4454** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4455** that parameter must be the byte offset
4456** where the NUL terminator would occur assuming the string were NUL
4457** terminated. If any NUL characters occurs at byte offsets less than
4458** the value of the fourth parameter then the resulting string value will
4459** contain embedded NULs. The result of expressions involving strings
4460** with embedded NULs is undefined.
4461**
4462** ^The fifth argument to the BLOB and string binding interfaces controls
4463** or indicates the lifetime of the object referenced by the third parameter.
4464** These three options exist:
4465** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4466** with it may be passed. ^It is called to dispose of the BLOB or string even
4467** if the call to the bind API fails, except the destructor is not called if
4468** the third parameter is a NULL pointer or the fourth parameter is negative.
4469** ^ (2) The special constant, [SQLITE_STATIC], may be passsed to indicate that
4470** the application remains responsible for disposing of the object. ^In this
4471** case, the object and the provided pointer to it must remain valid until
4472** either the prepared statement is finalized or the same SQL parameter is
4473** bound to something else, whichever occurs sooner.
4474** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4475** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4476** object and pointer to it must remain valid until then. ^SQLite will then
4477** manage the lifetime of its private copy.
4478**
4479** ^The sixth argument to sqlite3_bind_text64() must be one of
4480** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4481** to specify the encoding of the text in the third parameter. If
4482** the sixth argument to sqlite3_bind_text64() is not one of the
4483** allowed values shown above, or if the text encoding is different
4484** from the encoding specified by the sixth parameter, then the behavior
4485** is undefined.
4486**
4487** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4488** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4489** (just an integer to hold its size) while it is being processed.
4490** Zeroblobs are intended to serve as placeholders for BLOBs whose
4491** content is later written using
4492** [sqlite3_blob_open | incremental BLOB I/O] routines.
4493** ^A negative value for the zeroblob results in a zero-length BLOB.
4494**
4495** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4496** [prepared statement] S to have an SQL value of NULL, but to also be
4497** associated with the pointer P of type T. ^D is either a NULL pointer or
4498** a pointer to a destructor function for P. ^SQLite will invoke the
4499** destructor D with a single argument of P when it is finished using
4500** P. The T parameter should be a static string, preferably a string
4501** literal. The sqlite3_bind_pointer() routine is part of the
4502** [pointer passing interface] added for SQLite 3.20.0.
4503**
4504** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4505** for the [prepared statement] or with a prepared statement for which
4506** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4507** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4508** routine is passed a [prepared statement] that has been finalized, the
4509** result is undefined and probably harmful.
4510**
4511** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4512** ^Unbound parameters are interpreted as NULL.
4513**
4514** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4515** [error code] if anything goes wrong.
4516** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4517** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4518** [SQLITE_MAX_LENGTH].
4519** ^[SQLITE_RANGE] is returned if the parameter
4520** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4521**
4522** See also: [sqlite3_bind_parameter_count()],
4523** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4524*/
4525SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4526SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4527 void(*)(void*));
4528SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4529SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4530SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4531SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4532SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4533SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4534SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4535 void(*)(void*), unsigned char encoding);
4536SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4537SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4538SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4539SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4540
4541/*
4542** CAPI3REF: Number Of SQL Parameters
4543** METHOD: sqlite3_stmt
4544**
4545** ^This routine can be used to find the number of [SQL parameters]
4546** in a [prepared statement]. SQL parameters are tokens of the
4547** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4548** placeholders for values that are [sqlite3_bind_blob | bound]
4549** to the parameters at a later time.
4550**
4551** ^(This routine actually returns the index of the largest (rightmost)
4552** parameter. For all forms except ?NNN, this will correspond to the
4553** number of unique parameters. If parameters of the ?NNN form are used,
4554** there may be gaps in the list.)^
4555**
4556** See also: [sqlite3_bind_blob|sqlite3_bind()],
4557** [sqlite3_bind_parameter_name()], and
4558** [sqlite3_bind_parameter_index()].
4559*/
4560SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4561
4562/*
4563** CAPI3REF: Name Of A Host Parameter
4564** METHOD: sqlite3_stmt
4565**
4566** ^The sqlite3_bind_parameter_name(P,N) interface returns
4567** the name of the N-th [SQL parameter] in the [prepared statement] P.
4568** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4569** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4570** respectively.
4571** In other words, the initial ":" or "$" or "@" or "?"
4572** is included as part of the name.)^
4573** ^Parameters of the form "?" without a following integer have no name
4574** and are referred to as "nameless" or "anonymous parameters".
4575**
4576** ^The first host parameter has an index of 1, not 0.
4577**
4578** ^If the value N is out of range or if the N-th parameter is
4579** nameless, then NULL is returned. ^The returned string is
4580** always in UTF-8 encoding even if the named parameter was
4581** originally specified as UTF-16 in [sqlite3_prepare16()],
4582** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4583**
4584** See also: [sqlite3_bind_blob|sqlite3_bind()],
4585** [sqlite3_bind_parameter_count()], and
4586** [sqlite3_bind_parameter_index()].
4587*/
4588SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4589
4590/*
4591** CAPI3REF: Index Of A Parameter With A Given Name
4592** METHOD: sqlite3_stmt
4593**
4594** ^Return the index of an SQL parameter given its name. ^The
4595** index value returned is suitable for use as the second
4596** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4597** is returned if no matching parameter is found. ^The parameter
4598** name must be given in UTF-8 even if the original statement
4599** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4600** [sqlite3_prepare16_v3()].
4601**
4602** See also: [sqlite3_bind_blob|sqlite3_bind()],
4603** [sqlite3_bind_parameter_count()], and
4604** [sqlite3_bind_parameter_name()].
4605*/
4606SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4607
4608/*
4609** CAPI3REF: Reset All Bindings On A Prepared Statement
4610** METHOD: sqlite3_stmt
4611**
4612** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4613** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4614** ^Use this routine to reset all host parameters to NULL.
4615*/
4616SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4617
4618/*
4619** CAPI3REF: Number Of Columns In A Result Set
4620** METHOD: sqlite3_stmt
4621**
4622** ^Return the number of columns in the result set returned by the
4623** [prepared statement]. ^If this routine returns 0, that means the
4624** [prepared statement] returns no data (for example an [UPDATE]).
4625** ^However, just because this routine returns a positive number does not
4626** mean that one or more rows of data will be returned. ^A SELECT statement
4627** will always have a positive sqlite3_column_count() but depending on the
4628** WHERE clause constraints and the table content, it might return no rows.
4629**
4630** See also: [sqlite3_data_count()]
4631*/
4632SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4633
4634/*
4635** CAPI3REF: Column Names In A Result Set
4636** METHOD: sqlite3_stmt
4637**
4638** ^These routines return the name assigned to a particular column
4639** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4640** interface returns a pointer to a zero-terminated UTF-8 string
4641** and sqlite3_column_name16() returns a pointer to a zero-terminated
4642** UTF-16 string. ^The first parameter is the [prepared statement]
4643** that implements the [SELECT] statement. ^The second parameter is the
4644** column number. ^The leftmost column is number 0.
4645**
4646** ^The returned string pointer is valid until either the [prepared statement]
4647** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4648** reprepared by the first call to [sqlite3_step()] for a particular run
4649** or until the next call to
4650** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4651**
4652** ^If sqlite3_malloc() fails during the processing of either routine
4653** (for example during a conversion from UTF-8 to UTF-16) then a
4654** NULL pointer is returned.
4655**
4656** ^The name of a result column is the value of the "AS" clause for
4657** that column, if there is an AS clause. If there is no AS clause
4658** then the name of the column is unspecified and may change from
4659** one release of SQLite to the next.
4660*/
4661SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4662SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4663
4664/*
4665** CAPI3REF: Source Of Data In A Query Result
4666** METHOD: sqlite3_stmt
4667**
4668** ^These routines provide a means to determine the database, table, and
4669** table column that is the origin of a particular result column in
4670** [SELECT] statement.
4671** ^The name of the database or table or column can be returned as
4672** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4673** the database name, the _table_ routines return the table name, and
4674** the origin_ routines return the column name.
4675** ^The returned string is valid until the [prepared statement] is destroyed
4676** using [sqlite3_finalize()] or until the statement is automatically
4677** reprepared by the first call to [sqlite3_step()] for a particular run
4678** or until the same information is requested
4679** again in a different encoding.
4680**
4681** ^The names returned are the original un-aliased names of the
4682** database, table, and column.
4683**
4684** ^The first argument to these interfaces is a [prepared statement].
4685** ^These functions return information about the Nth result column returned by
4686** the statement, where N is the second function argument.
4687** ^The left-most column is column 0 for these routines.
4688**
4689** ^If the Nth column returned by the statement is an expression or
4690** subquery and is not a column value, then all of these functions return
4691** NULL. ^These routines might also return NULL if a memory allocation error
4692** occurs. ^Otherwise, they return the name of the attached database, table,
4693** or column that query result column was extracted from.
4694**
4695** ^As with all other SQLite APIs, those whose names end with "16" return
4696** UTF-16 encoded strings and the other functions return UTF-8.
4697**
4698** ^These APIs are only available if the library was compiled with the
4699** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4700**
4701** If two or more threads call one or more
4702** [sqlite3_column_database_name | column metadata interfaces]
4703** for the same [prepared statement] and result column
4704** at the same time then the results are undefined.
4705*/
4706SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4707SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4708SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4709SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4710SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4711SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4712
4713/*
4714** CAPI3REF: Declared Datatype Of A Query Result
4715** METHOD: sqlite3_stmt
4716**
4717** ^(The first parameter is a [prepared statement].
4718** If this statement is a [SELECT] statement and the Nth column of the
4719** returned result set of that [SELECT] is a table column (not an
4720** expression or subquery) then the declared type of the table
4721** column is returned.)^ ^If the Nth column of the result set is an
4722** expression or subquery, then a NULL pointer is returned.
4723** ^The returned string is always UTF-8 encoded.
4724**
4725** ^(For example, given the database schema:
4726**
4727** CREATE TABLE t1(c1 VARIANT);
4728**
4729** and the following statement to be compiled:
4730**
4731** SELECT c1 + 1, c1 FROM t1;
4732**
4733** this routine would return the string "VARIANT" for the second result
4734** column (i==1), and a NULL pointer for the first result column (i==0).)^
4735**
4736** ^SQLite uses dynamic run-time typing. ^So just because a column
4737** is declared to contain a particular type does not mean that the
4738** data stored in that column is of the declared type. SQLite is
4739** strongly typed, but the typing is dynamic not static. ^Type
4740** is associated with individual values, not with the containers
4741** used to hold those values.
4742*/
4743SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4744SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4745
4746/*
4747** CAPI3REF: Evaluate An SQL Statement
4748** METHOD: sqlite3_stmt
4749**
4750** After a [prepared statement] has been prepared using any of
4751** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4752** or [sqlite3_prepare16_v3()] or one of the legacy
4753** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4754** must be called one or more times to evaluate the statement.
4755**
4756** The details of the behavior of the sqlite3_step() interface depend
4757** on whether the statement was prepared using the newer "vX" interfaces
4758** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4759** [sqlite3_prepare16_v2()] or the older legacy
4760** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4761** new "vX" interface is recommended for new applications but the legacy
4762** interface will continue to be supported.
4763**
4764** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4765** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4766** ^With the "v2" interface, any of the other [result codes] or
4767** [extended result codes] might be returned as well.
4768**
4769** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4770** database locks it needs to do its job. ^If the statement is a [COMMIT]
4771** or occurs outside of an explicit transaction, then you can retry the
4772** statement. If the statement is not a [COMMIT] and occurs within an
4773** explicit transaction then you should rollback the transaction before
4774** continuing.
4775**
4776** ^[SQLITE_DONE] means that the statement has finished executing
4777** successfully. sqlite3_step() should not be called again on this virtual
4778** machine without first calling [sqlite3_reset()] to reset the virtual
4779** machine back to its initial state.
4780**
4781** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4782** is returned each time a new row of data is ready for processing by the
4783** caller. The values may be accessed using the [column access functions].
4784** sqlite3_step() is called again to retrieve the next row of data.
4785**
4786** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4787** violation) has occurred. sqlite3_step() should not be called again on
4788** the VM. More information may be found by calling [sqlite3_errmsg()].
4789** ^With the legacy interface, a more specific error code (for example,
4790** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4791** can be obtained by calling [sqlite3_reset()] on the
4792** [prepared statement]. ^In the "v2" interface,
4793** the more specific error code is returned directly by sqlite3_step().
4794**
4795** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4796** Perhaps it was called on a [prepared statement] that has
4797** already been [sqlite3_finalize | finalized] or on one that had
4798** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4799** be the case that the same database connection is being used by two or
4800** more threads at the same moment in time.
4801**
4802** For all versions of SQLite up to and including 3.6.23.1, a call to
4803** [sqlite3_reset()] was required after sqlite3_step() returned anything
4804** other than [SQLITE_ROW] before any subsequent invocation of
4805** sqlite3_step(). Failure to reset the prepared statement using
4806** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4807** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4808** sqlite3_step() began
4809** calling [sqlite3_reset()] automatically in this circumstance rather
4810** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4811** break because any application that ever receives an SQLITE_MISUSE error
4812** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4813** can be used to restore the legacy behavior.
4814**
4815** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4816** API always returns a generic error code, [SQLITE_ERROR], following any
4817** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4818** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4819** specific [error codes] that better describes the error.
4820** We admit that this is a goofy design. The problem has been fixed
4821** with the "v2" interface. If you prepare all of your SQL statements
4822** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4823** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
4824** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
4825** then the more specific [error codes] are returned directly
4826** by sqlite3_step(). The use of the "vX" interfaces is recommended.
4827*/
4828SQLITE_API int sqlite3_step(sqlite3_stmt*);
4829
4830/*
4831** CAPI3REF: Number of columns in a result set
4832** METHOD: sqlite3_stmt
4833**
4834** ^The sqlite3_data_count(P) interface returns the number of columns in the
4835** current row of the result set of [prepared statement] P.
4836** ^If prepared statement P does not have results ready to return
4837** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
4838** interfaces) then sqlite3_data_count(P) returns 0.
4839** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
4840** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
4841** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
4842** will return non-zero if previous call to [sqlite3_step](P) returned
4843** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
4844** where it always returns zero since each step of that multi-step
4845** pragma returns 0 columns of data.
4846**
4847** See also: [sqlite3_column_count()]
4848*/
4849SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
4850
4851/*
4852** CAPI3REF: Fundamental Datatypes
4853** KEYWORDS: SQLITE_TEXT
4854**
4855** ^(Every value in SQLite has one of five fundamental datatypes:
4856**
4857** <ul>
4858** <li> 64-bit signed integer
4859** <li> 64-bit IEEE floating point number
4860** <li> string
4861** <li> BLOB
4862** <li> NULL
4863** </ul>)^
4864**
4865** These constants are codes for each of those types.
4866**
4867** Note that the SQLITE_TEXT constant was also used in SQLite version 2
4868** for a completely different meaning. Software that links against both
4869** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
4870** SQLITE_TEXT.
4871*/
4872#define SQLITE_INTEGER 1
4873#define SQLITE_FLOAT 2
4874#define SQLITE_BLOB 4
4875#define SQLITE_NULL 5
4876#ifdef SQLITE_TEXT
4877# undef SQLITE_TEXT
4878#else
4879# define SQLITE_TEXT 3
4880#endif
4881#define SQLITE3_TEXT 3
4882
4883/*
4884** CAPI3REF: Result Values From A Query
4885** KEYWORDS: {column access functions}
4886** METHOD: sqlite3_stmt
4887**
4888** <b>Summary:</b>
4889** <blockquote><table border=0 cellpadding=0 cellspacing=0>
4890** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
4891** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
4892** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
4893** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
4894** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
4895** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
4896** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
4897** [sqlite3_value|unprotected sqlite3_value] object.
4898** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
4899** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
4900** or a UTF-8 TEXT result in bytes
4901** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
4902** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
4903** TEXT in bytes
4904** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
4905** datatype of the result
4906** </table></blockquote>
4907**
4908** <b>Details:</b>
4909**
4910** ^These routines return information about a single column of the current
4911** result row of a query. ^In every case the first argument is a pointer
4912** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
4913** that was returned from [sqlite3_prepare_v2()] or one of its variants)
4914** and the second argument is the index of the column for which information
4915** should be returned. ^The leftmost column of the result set has the index 0.
4916** ^The number of columns in the result can be determined using
4917** [sqlite3_column_count()].
4918**
4919** If the SQL statement does not currently point to a valid row, or if the
4920** column index is out of range, the result is undefined.
4921** These routines may only be called when the most recent call to
4922** [sqlite3_step()] has returned [SQLITE_ROW] and neither
4923** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
4924** If any of these routines are called after [sqlite3_reset()] or
4925** [sqlite3_finalize()] or after [sqlite3_step()] has returned
4926** something other than [SQLITE_ROW], the results are undefined.
4927** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4928** are called from a different thread while any of these routines
4929** are pending, then the results are undefined.
4930**
4931** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
4932** each return the value of a result column in a specific data format. If
4933** the result column is not initially in the requested format (for example,
4934** if the query returns an integer but the sqlite3_column_text() interface
4935** is used to extract the value) then an automatic type conversion is performed.
4936**
4937** ^The sqlite3_column_type() routine returns the
4938** [SQLITE_INTEGER | datatype code] for the initial data type
4939** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4940** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
4941** The return value of sqlite3_column_type() can be used to decide which
4942** of the first six interface should be used to extract the column value.
4943** The value returned by sqlite3_column_type() is only meaningful if no
4944** automatic type conversions have occurred for the value in question.
4945** After a type conversion, the result of calling sqlite3_column_type()
4946** is undefined, though harmless. Future
4947** versions of SQLite may change the behavior of sqlite3_column_type()
4948** following a type conversion.
4949**
4950** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
4951** or sqlite3_column_bytes16() interfaces can be used to determine the size
4952** of that BLOB or string.
4953**
4954** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4955** routine returns the number of bytes in that BLOB or string.
4956** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4957** the string to UTF-8 and then returns the number of bytes.
4958** ^If the result is a numeric value then sqlite3_column_bytes() uses
4959** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4960** the number of bytes in that string.
4961** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4962**
4963** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4964** routine returns the number of bytes in that BLOB or string.
4965** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4966** the string to UTF-16 and then returns the number of bytes.
4967** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4968** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4969** the number of bytes in that string.
4970** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4971**
4972** ^The values returned by [sqlite3_column_bytes()] and
4973** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4974** of the string. ^For clarity: the values returned by
4975** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4976** bytes in the string, not the number of characters.
4977**
4978** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4979** even empty strings, are always zero-terminated. ^The return
4980** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4981**
4982** ^Strings returned by sqlite3_column_text16() always have the endianness
4983** which is native to the platform, regardless of the text encoding set
4984** for the database.
4985**
4986** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4987** [unprotected sqlite3_value] object. In a multithreaded environment,
4988** an unprotected sqlite3_value object may only be used safely with
4989** [sqlite3_bind_value()] and [sqlite3_result_value()].
4990** If the [unprotected sqlite3_value] object returned by
4991** [sqlite3_column_value()] is used in any other way, including calls
4992** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4993** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4994** Hence, the sqlite3_column_value() interface
4995** is normally only useful within the implementation of
4996** [application-defined SQL functions] or [virtual tables], not within
4997** top-level application code.
4998**
4999** These routines may attempt to convert the datatype of the result.
5000** ^For example, if the internal representation is FLOAT and a text result
5001** is requested, [sqlite3_snprintf()] is used internally to perform the
5002** conversion automatically. ^(The following table details the conversions
5003** that are applied:
5004**
5005** <blockquote>
5006** <table border="1">
5007** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5008**
5009** <tr><td> NULL <td> INTEGER <td> Result is 0
5010** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5011** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5012** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5013** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5014** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5015** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5016** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5017** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5018** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5019** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5020** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5021** <tr><td> TEXT <td> BLOB <td> No change
5022** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5023** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5024** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5025** </table>
5026** </blockquote>)^
5027**
5028** Note that when type conversions occur, pointers returned by prior
5029** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5030** sqlite3_column_text16() may be invalidated.
5031** Type conversions and pointer invalidations might occur
5032** in the following cases:
5033**
5034** <ul>
5035** <li> The initial content is a BLOB and sqlite3_column_text() or
5036** sqlite3_column_text16() is called. A zero-terminator might
5037** need to be added to the string.</li>
5038** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5039** sqlite3_column_text16() is called. The content must be converted
5040** to UTF-16.</li>
5041** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5042** sqlite3_column_text() is called. The content must be converted
5043** to UTF-8.</li>
5044** </ul>
5045**
5046** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5047** not invalidate a prior pointer, though of course the content of the buffer
5048** that the prior pointer references will have been modified. Other kinds
5049** of conversion are done in place when it is possible, but sometimes they
5050** are not possible and in those cases prior pointers are invalidated.
5051**
5052** The safest policy is to invoke these routines
5053** in one of the following ways:
5054**
5055** <ul>
5056** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5057** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5058** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5059** </ul>
5060**
5061** In other words, you should call sqlite3_column_text(),
5062** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5063** into the desired format, then invoke sqlite3_column_bytes() or
5064** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5065** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5066** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5067** with calls to sqlite3_column_bytes().
5068**
5069** ^The pointers returned are valid until a type conversion occurs as
5070** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5071** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5072** and BLOBs is freed automatically. Do not pass the pointers returned
5073** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5074** [sqlite3_free()].
5075**
5076** As long as the input parameters are correct, these routines will only
5077** fail if an out-of-memory error occurs during a format conversion.
5078** Only the following subset of interfaces are subject to out-of-memory
5079** errors:
5080**
5081** <ul>
5082** <li> sqlite3_column_blob()
5083** <li> sqlite3_column_text()
5084** <li> sqlite3_column_text16()
5085** <li> sqlite3_column_bytes()
5086** <li> sqlite3_column_bytes16()
5087** </ul>
5088**
5089** If an out-of-memory error occurs, then the return value from these
5090** routines is the same as if the column had contained an SQL NULL value.
5091** Valid SQL NULL returns can be distinguished from out-of-memory errors
5092** by invoking the [sqlite3_errcode()] immediately after the suspect
5093** return value is obtained and before any
5094** other SQLite interface is called on the same [database connection].
5095*/
5096SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5097SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5098SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5099SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5100SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5101SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5102SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5103SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5104SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5105SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5106
5107/*
5108** CAPI3REF: Destroy A Prepared Statement Object
5109** DESTRUCTOR: sqlite3_stmt
5110**
5111** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5112** ^If the most recent evaluation of the statement encountered no errors
5113** or if the statement is never been evaluated, then sqlite3_finalize() returns
5114** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5115** sqlite3_finalize(S) returns the appropriate [error code] or
5116** [extended error code].
5117**
5118** ^The sqlite3_finalize(S) routine can be called at any point during
5119** the life cycle of [prepared statement] S:
5120** before statement S is ever evaluated, after
5121** one or more calls to [sqlite3_reset()], or after any call
5122** to [sqlite3_step()] regardless of whether or not the statement has
5123** completed execution.
5124**
5125** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5126**
5127** The application must finalize every [prepared statement] in order to avoid
5128** resource leaks. It is a grievous error for the application to try to use
5129** a prepared statement after it has been finalized. Any use of a prepared
5130** statement after it has been finalized can result in undefined and
5131** undesirable behavior such as segfaults and heap corruption.
5132*/
5133SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5134
5135/*
5136** CAPI3REF: Reset A Prepared Statement Object
5137** METHOD: sqlite3_stmt
5138**
5139** The sqlite3_reset() function is called to reset a [prepared statement]
5140** object back to its initial state, ready to be re-executed.
5141** ^Any SQL statement variables that had values bound to them using
5142** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5143** Use [sqlite3_clear_bindings()] to reset the bindings.
5144**
5145** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5146** back to the beginning of its program.
5147**
5148** ^If the most recent call to [sqlite3_step(S)] for the
5149** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
5150** or if [sqlite3_step(S)] has never before been called on S,
5151** then [sqlite3_reset(S)] returns [SQLITE_OK].
5152**
5153** ^If the most recent call to [sqlite3_step(S)] for the
5154** [prepared statement] S indicated an error, then
5155** [sqlite3_reset(S)] returns an appropriate [error code].
5156**
5157** ^The [sqlite3_reset(S)] interface does not change the values
5158** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5159*/
5160SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5161
5162/*
5163** CAPI3REF: Create Or Redefine SQL Functions
5164** KEYWORDS: {function creation routines}
5165** METHOD: sqlite3
5166**
5167** ^These functions (collectively known as "function creation routines")
5168** are used to add SQL functions or aggregates or to redefine the behavior
5169** of existing SQL functions or aggregates. The only differences between
5170** the three "sqlite3_create_function*" routines are the text encoding
5171** expected for the second parameter (the name of the function being
5172** created) and the presence or absence of a destructor callback for
5173** the application data pointer. Function sqlite3_create_window_function()
5174** is similar, but allows the user to supply the extra callback functions
5175** needed by [aggregate window functions].
5176**
5177** ^The first parameter is the [database connection] to which the SQL
5178** function is to be added. ^If an application uses more than one database
5179** connection then application-defined SQL functions must be added
5180** to each database connection separately.
5181**
5182** ^The second parameter is the name of the SQL function to be created or
5183** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5184** representation, exclusive of the zero-terminator. ^Note that the name
5185** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5186** ^Any attempt to create a function with a longer name
5187** will result in [SQLITE_MISUSE] being returned.
5188**
5189** ^The third parameter (nArg)
5190** is the number of arguments that the SQL function or
5191** aggregate takes. ^If this parameter is -1, then the SQL function or
5192** aggregate may take any number of arguments between 0 and the limit
5193** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5194** parameter is less than -1 or greater than 127 then the behavior is
5195** undefined.
5196**
5197** ^The fourth parameter, eTextRep, specifies what
5198** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5199** its parameters. The application should set this parameter to
5200** [SQLITE_UTF16LE] if the function implementation invokes
5201** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5202** implementation invokes [sqlite3_value_text16be()] on an input, or
5203** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5204** otherwise. ^The same SQL function may be registered multiple times using
5205** different preferred text encodings, with different implementations for
5206** each encoding.
5207** ^When multiple implementations of the same function are available, SQLite
5208** will pick the one that involves the least amount of data conversion.
5209**
5210** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5211** to signal that the function will always return the same result given
5212** the same inputs within a single SQL statement. Most SQL functions are
5213** deterministic. The built-in [random()] SQL function is an example of a
5214** function that is not deterministic. The SQLite query planner is able to
5215** perform additional optimizations on deterministic functions, so use
5216** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5217**
5218** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5219** flag, which if present prevents the function from being invoked from
5220** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5221** index expressions, or the WHERE clause of partial indexes.
5222**
5223** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5224** all application-defined SQL functions that do not need to be
5225** used inside of triggers, view, CHECK constraints, or other elements of
5226** the database schema. This flags is especially recommended for SQL
5227** functions that have side effects or reveal internal application state.
5228** Without this flag, an attacker might be able to modify the schema of
5229** a database file to include invocations of the function with parameters
5230** chosen by the attacker, which the application will then execute when
5231** the database file is opened and read.
5232**
5233** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5234** function can gain access to this pointer using [sqlite3_user_data()].)^
5235**
5236** ^The sixth, seventh and eighth parameters passed to the three
5237** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5238** pointers to C-language functions that implement the SQL function or
5239** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5240** callback only; NULL pointers must be passed as the xStep and xFinal
5241** parameters. ^An aggregate SQL function requires an implementation of xStep
5242** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5243** SQL function or aggregate, pass NULL pointers for all three function
5244** callbacks.
5245**
5246** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5247** and xInverse) passed to sqlite3_create_window_function are pointers to
5248** C-language callbacks that implement the new function. xStep and xFinal
5249** must both be non-NULL. xValue and xInverse may either both be NULL, in
5250** which case a regular aggregate function is created, or must both be
5251** non-NULL, in which case the new function may be used as either an aggregate
5252** or aggregate window function. More details regarding the implementation
5253** of aggregate window functions are
5254** [user-defined window functions|available here].
5255**
5256** ^(If the final parameter to sqlite3_create_function_v2() or
5257** sqlite3_create_window_function() is not NULL, then it is destructor for
5258** the application data pointer. The destructor is invoked when the function
5259** is deleted, either by being overloaded or when the database connection
5260** closes.)^ ^The destructor is also invoked if the call to
5261** sqlite3_create_function_v2() fails. ^When the destructor callback is
5262** invoked, it is passed a single argument which is a copy of the application
5263** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5264**
5265** ^It is permitted to register multiple implementations of the same
5266** functions with the same name but with either differing numbers of
5267** arguments or differing preferred text encodings. ^SQLite will use
5268** the implementation that most closely matches the way in which the
5269** SQL function is used. ^A function implementation with a non-negative
5270** nArg parameter is a better match than a function implementation with
5271** a negative nArg. ^A function where the preferred text encoding
5272** matches the database encoding is a better
5273** match than a function where the encoding is different.
5274** ^A function where the encoding difference is between UTF16le and UTF16be
5275** is a closer match than a function where the encoding difference is
5276** between UTF8 and UTF16.
5277**
5278** ^Built-in functions may be overloaded by new application-defined functions.
5279**
5280** ^An application-defined function is permitted to call other
5281** SQLite interfaces. However, such calls must not
5282** close the database connection nor finalize or reset the prepared
5283** statement in which the function is running.
5284*/
5285SQLITE_API int sqlite3_create_function(
5286 sqlite3 *db,
5287 const char *zFunctionName,
5288 int nArg,
5289 int eTextRep,
5290 void *pApp,
5291 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5292 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5293 void (*xFinal)(sqlite3_context*)
5294);
5295SQLITE_API int sqlite3_create_function16(
5296 sqlite3 *db,
5297 const void *zFunctionName,
5298 int nArg,
5299 int eTextRep,
5300 void *pApp,
5301 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5302 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5303 void (*xFinal)(sqlite3_context*)
5304);
5305SQLITE_API int sqlite3_create_function_v2(
5306 sqlite3 *db,
5307 const char *zFunctionName,
5308 int nArg,
5309 int eTextRep,
5310 void *pApp,
5311 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5312 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5313 void (*xFinal)(sqlite3_context*),
5314 void(*xDestroy)(void*)
5315);
5316SQLITE_API int sqlite3_create_window_function(
5317 sqlite3 *db,
5318 const char *zFunctionName,
5319 int nArg,
5320 int eTextRep,
5321 void *pApp,
5322 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5323 void (*xFinal)(sqlite3_context*),
5324 void (*xValue)(sqlite3_context*),
5325 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5326 void(*xDestroy)(void*)
5327);
5328
5329/*
5330** CAPI3REF: Text Encodings
5331**
5332** These constant define integer codes that represent the various
5333** text encodings supported by SQLite.
5334*/
5335#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5336#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5337#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5338#define SQLITE_UTF16 4 /* Use native byte order */
5339#define SQLITE_ANY 5 /* Deprecated */
5340#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5341
5342/*
5343** CAPI3REF: Function Flags
5344**
5345** These constants may be ORed together with the
5346** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5347** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5348** [sqlite3_create_function_v2()].
5349**
5350** <dl>
5351** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5352** The SQLITE_DETERMINISTIC flag means that the new function always gives
5353** the same output when the input parameters are the same.
5354** The [abs|abs() function] is deterministic, for example, but
5355** [randomblob|randomblob()] is not. Functions must
5356** be deterministic in order to be used in certain contexts such as
5357** with the WHERE clause of [partial indexes] or in [generated columns].
5358** SQLite might also optimize deterministic functions by factoring them
5359** out of inner loops.
5360** </dd>
5361**
5362** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5363** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5364** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5365** schema structures such as [CHECK constraints], [DEFAULT clauses],
5366** [expression indexes], [partial indexes], or [generated columns].
5367** The SQLITE_DIRECTONLY flags is a security feature which is recommended
5368** for all [application-defined SQL functions], and especially for functions
5369** that have side-effects or that could potentially leak sensitive
5370** information.
5371** </dd>
5372**
5373** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5374** The SQLITE_INNOCUOUS flag means that the function is unlikely
5375** to cause problems even if misused. An innocuous function should have
5376** no side effects and should not depend on any values other than its
5377** input parameters. The [abs|abs() function] is an example of an
5378** innocuous function.
5379** The [load_extension() SQL function] is not innocuous because of its
5380** side effects.
5381** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5382** exactly the same. The [random|random() function] is an example of a
5383** function that is innocuous but not deterministic.
5384** <p>Some heightened security settings
5385** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5386** disable the use of SQL functions inside views and triggers and in
5387** schema structures such as [CHECK constraints], [DEFAULT clauses],
5388** [expression indexes], [partial indexes], and [generated columns] unless
5389** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5390** are innocuous. Developers are advised to avoid using the
5391** SQLITE_INNOCUOUS flag for application-defined functions unless the
5392** function has been carefully audited and found to be free of potentially
5393** security-adverse side-effects and information-leaks.
5394** </dd>
5395**
5396** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5397** The SQLITE_SUBTYPE flag indicates to SQLite that a function may call
5398** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5399** Specifying this flag makes no difference for scalar or aggregate user
5400** functions. However, if it is not specified for a user-defined window
5401** function, then any sub-types belonging to arguments passed to the window
5402** function may be discarded before the window function is called (i.e.
5403** sqlite3_value_subtype() will always return 0).
5404** </dd>
5405** </dl>
5406*/
5407#define SQLITE_DETERMINISTIC 0x000000800
5408#define SQLITE_DIRECTONLY 0x000080000
5409#define SQLITE_SUBTYPE 0x000100000
5410#define SQLITE_INNOCUOUS 0x000200000
5411
5412/*
5413** CAPI3REF: Deprecated Functions
5414** DEPRECATED
5415**
5416** These functions are [deprecated]. In order to maintain
5417** backwards compatibility with older code, these functions continue
5418** to be supported. However, new applications should avoid
5419** the use of these functions. To encourage programmers to avoid
5420** these functions, we will not explain what they do.
5421*/
5422#ifndef SQLITE_OMIT_DEPRECATED
5423SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5424SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5425SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5426SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5427SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5428SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5429 void*,sqlite3_int64);
5430#endif
5431
5432/*
5433** CAPI3REF: Obtaining SQL Values
5434** METHOD: sqlite3_value
5435**
5436** <b>Summary:</b>
5437** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5438** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
5439** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
5440** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
5441** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
5442** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
5443** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
5444** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
5445** the native byteorder
5446** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
5447** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
5448** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5449** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
5450** or a UTF-8 TEXT in bytes
5451** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
5452** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5453** TEXT in bytes
5454** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
5455** datatype of the value
5456** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
5457** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
5458** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
5459** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
5460** against a virtual table.
5461** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
5462** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
5463** </table></blockquote>
5464**
5465** <b>Details:</b>
5466**
5467** These routines extract type, size, and content information from
5468** [protected sqlite3_value] objects. Protected sqlite3_value objects
5469** are used to pass parameter information into the functions that
5470** implement [application-defined SQL functions] and [virtual tables].
5471**
5472** These routines work only with [protected sqlite3_value] objects.
5473** Any attempt to use these routines on an [unprotected sqlite3_value]
5474** is not threadsafe.
5475**
5476** ^These routines work just like the corresponding [column access functions]
5477** except that these routines take a single [protected sqlite3_value] object
5478** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5479**
5480** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5481** in the native byte-order of the host machine. ^The
5482** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5483** extract UTF-16 strings as big-endian and little-endian respectively.
5484**
5485** ^If [sqlite3_value] object V was initialized
5486** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5487** and if X and Y are strings that compare equal according to strcmp(X,Y),
5488** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5489** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5490** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5491**
5492** ^(The sqlite3_value_type(V) interface returns the
5493** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5494** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5495** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5496** Other interfaces might change the datatype for an sqlite3_value object.
5497** For example, if the datatype is initially SQLITE_INTEGER and
5498** sqlite3_value_text(V) is called to extract a text value for that
5499** integer, then subsequent calls to sqlite3_value_type(V) might return
5500** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5501** occurs is undefined and may change from one release of SQLite to the next.
5502**
5503** ^(The sqlite3_value_numeric_type() interface attempts to apply
5504** numeric affinity to the value. This means that an attempt is
5505** made to convert the value to an integer or floating point. If
5506** such a conversion is possible without loss of information (in other
5507** words, if the value is a string that looks like a number)
5508** then the conversion is performed. Otherwise no conversion occurs.
5509** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5510**
5511** ^Within the [xUpdate] method of a [virtual table], the
5512** sqlite3_value_nochange(X) interface returns true if and only if
5513** the column corresponding to X is unchanged by the UPDATE operation
5514** that the xUpdate method call was invoked to implement and if
5515** and the prior [xColumn] method call that was invoked to extracted
5516** the value for that column returned without setting a result (probably
5517** because it queried [sqlite3_vtab_nochange()] and found that the column
5518** was unchanging). ^Within an [xUpdate] method, any value for which
5519** sqlite3_value_nochange(X) is true will in all other respects appear
5520** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5521** than within an [xUpdate] method call for an UPDATE statement, then
5522** the return value is arbitrary and meaningless.
5523**
5524** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5525** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5526** interfaces. ^If X comes from an SQL literal value, or a table column,
5527** or an expression, then sqlite3_value_frombind(X) returns zero.
5528**
5529** Please pay particular attention to the fact that the pointer returned
5530** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5531** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5532** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5533** or [sqlite3_value_text16()].
5534**
5535** These routines must be called from the same thread as
5536** the SQL function that supplied the [sqlite3_value*] parameters.
5537**
5538** As long as the input parameter is correct, these routines can only
5539** fail if an out-of-memory error occurs during a format conversion.
5540** Only the following subset of interfaces are subject to out-of-memory
5541** errors:
5542**
5543** <ul>
5544** <li> sqlite3_value_blob()
5545** <li> sqlite3_value_text()
5546** <li> sqlite3_value_text16()
5547** <li> sqlite3_value_text16le()
5548** <li> sqlite3_value_text16be()
5549** <li> sqlite3_value_bytes()
5550** <li> sqlite3_value_bytes16()
5551** </ul>
5552**
5553** If an out-of-memory error occurs, then the return value from these
5554** routines is the same as if the column had contained an SQL NULL value.
5555** Valid SQL NULL returns can be distinguished from out-of-memory errors
5556** by invoking the [sqlite3_errcode()] immediately after the suspect
5557** return value is obtained and before any
5558** other SQLite interface is called on the same [database connection].
5559*/
5560SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5561SQLITE_API double sqlite3_value_double(sqlite3_value*);
5562SQLITE_API int sqlite3_value_int(sqlite3_value*);
5563SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5564SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5565SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5566SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5567SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5568SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5569SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5570SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5571SQLITE_API int sqlite3_value_type(sqlite3_value*);
5572SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5573SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5574SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5575
5576/*
5577** CAPI3REF: Finding The Subtype Of SQL Values
5578** METHOD: sqlite3_value
5579**
5580** The sqlite3_value_subtype(V) function returns the subtype for
5581** an [application-defined SQL function] argument V. The subtype
5582** information can be used to pass a limited amount of context from
5583** one SQL function to another. Use the [sqlite3_result_subtype()]
5584** routine to set the subtype for the return value of an SQL function.
5585*/
5586SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5587
5588/*
5589** CAPI3REF: Copy And Free SQL Values
5590** METHOD: sqlite3_value
5591**
5592** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5593** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5594** is a [protected sqlite3_value] object even if the input is not.
5595** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5596** memory allocation fails. ^If V is a [pointer value], then the result
5597** of sqlite3_value_dup(V) is a NULL value.
5598**
5599** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5600** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5601** then sqlite3_value_free(V) is a harmless no-op.
5602*/
5603SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5604SQLITE_API void sqlite3_value_free(sqlite3_value*);
5605
5606/*
5607** CAPI3REF: Obtain Aggregate Function Context
5608** METHOD: sqlite3_context
5609**
5610** Implementations of aggregate SQL functions use this
5611** routine to allocate memory for storing their state.
5612**
5613** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5614** for a particular aggregate function, SQLite allocates
5615** N bytes of memory, zeroes out that memory, and returns a pointer
5616** to the new memory. ^On second and subsequent calls to
5617** sqlite3_aggregate_context() for the same aggregate function instance,
5618** the same buffer is returned. Sqlite3_aggregate_context() is normally
5619** called once for each invocation of the xStep callback and then one
5620** last time when the xFinal callback is invoked. ^(When no rows match
5621** an aggregate query, the xStep() callback of the aggregate function
5622** implementation is never called and xFinal() is called exactly once.
5623** In those cases, sqlite3_aggregate_context() might be called for the
5624** first time from within xFinal().)^
5625**
5626** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5627** when first called if N is less than or equal to zero or if a memory
5628** allocate error occurs.
5629**
5630** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5631** determined by the N parameter on first successful call. Changing the
5632** value of N in any subsequent call to sqlite3_aggregate_context() within
5633** the same aggregate function instance will not resize the memory
5634** allocation.)^ Within the xFinal callback, it is customary to set
5635** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5636** pointless memory allocations occur.
5637**
5638** ^SQLite automatically frees the memory allocated by
5639** sqlite3_aggregate_context() when the aggregate query concludes.
5640**
5641** The first parameter must be a copy of the
5642** [sqlite3_context | SQL function context] that is the first parameter
5643** to the xStep or xFinal callback routine that implements the aggregate
5644** function.
5645**
5646** This routine must be called from the same thread in which
5647** the aggregate SQL function is running.
5648*/
5649SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5650
5651/*
5652** CAPI3REF: User Data For Functions
5653** METHOD: sqlite3_context
5654**
5655** ^The sqlite3_user_data() interface returns a copy of
5656** the pointer that was the pUserData parameter (the 5th parameter)
5657** of the [sqlite3_create_function()]
5658** and [sqlite3_create_function16()] routines that originally
5659** registered the application defined function.
5660**
5661** This routine must be called from the same thread in which
5662** the application-defined function is running.
5663*/
5664SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5665
5666/*
5667** CAPI3REF: Database Connection For Functions
5668** METHOD: sqlite3_context
5669**
5670** ^The sqlite3_context_db_handle() interface returns a copy of
5671** the pointer to the [database connection] (the 1st parameter)
5672** of the [sqlite3_create_function()]
5673** and [sqlite3_create_function16()] routines that originally
5674** registered the application defined function.
5675*/
5676SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5677
5678/*
5679** CAPI3REF: Function Auxiliary Data
5680** METHOD: sqlite3_context
5681**
5682** These functions may be used by (non-aggregate) SQL functions to
5683** associate metadata with argument values. If the same value is passed to
5684** multiple invocations of the same SQL function during query execution, under
5685** some circumstances the associated metadata may be preserved. An example
5686** of where this might be useful is in a regular-expression matching
5687** function. The compiled version of the regular expression can be stored as
5688** metadata associated with the pattern string.
5689** Then as long as the pattern string remains the same,
5690** the compiled regular expression can be reused on multiple
5691** invocations of the same function.
5692**
5693** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the metadata
5694** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5695** value to the application-defined function. ^N is zero for the left-most
5696** function argument. ^If there is no metadata
5697** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5698** returns a NULL pointer.
5699**
5700** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
5701** argument of the application-defined function. ^Subsequent
5702** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5703** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
5704** NULL if the metadata has been discarded.
5705** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5706** SQLite will invoke the destructor function X with parameter P exactly
5707** once, when the metadata is discarded.
5708** SQLite is free to discard the metadata at any time, including: <ul>
5709** <li> ^(when the corresponding function parameter changes)^, or
5710** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5711** SQL statement)^, or
5712** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5713** parameter)^, or
5714** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5715** allocation error occurs.)^ </ul>
5716**
5717** Note the last bullet in particular. The destructor X in
5718** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5719** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5720** should be called near the end of the function implementation and the
5721** function implementation should not make any use of P after
5722** sqlite3_set_auxdata() has been called.
5723**
5724** ^(In practice, metadata is preserved between function calls for
5725** function parameters that are compile-time constants, including literal
5726** values and [parameters] and expressions composed from the same.)^
5727**
5728** The value of the N parameter to these interfaces should be non-negative.
5729** Future enhancements may make use of negative N values to define new
5730** kinds of function caching behavior.
5731**
5732** These routines must be called from the same thread in which
5733** the SQL function is running.
5734*/
5735SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5736SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5737
5738
5739/*
5740** CAPI3REF: Constants Defining Special Destructor Behavior
5741**
5742** These are special values for the destructor that is passed in as the
5743** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
5744** argument is SQLITE_STATIC, it means that the content pointer is constant
5745** and will never change. It does not need to be destroyed. ^The
5746** SQLITE_TRANSIENT value means that the content will likely change in
5747** the near future and that SQLite should make its own private copy of
5748** the content before returning.
5749**
5750** The typedef is necessary to work around problems in certain
5751** C++ compilers.
5752*/
5753typedef void (*sqlite3_destructor_type)(void*);
5754#define SQLITE_STATIC ((sqlite3_destructor_type)0)
5755#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
5756
5757/*
5758** CAPI3REF: Setting The Result Of An SQL Function
5759** METHOD: sqlite3_context
5760**
5761** These routines are used by the xFunc or xFinal callbacks that
5762** implement SQL functions and aggregates. See
5763** [sqlite3_create_function()] and [sqlite3_create_function16()]
5764** for additional information.
5765**
5766** These functions work very much like the [parameter binding] family of
5767** functions used to bind values to host parameters in prepared statements.
5768** Refer to the [SQL parameter] documentation for additional information.
5769**
5770** ^The sqlite3_result_blob() interface sets the result from
5771** an application-defined function to be the BLOB whose content is pointed
5772** to by the second parameter and which is N bytes long where N is the
5773** third parameter.
5774**
5775** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
5776** interfaces set the result of the application-defined function to be
5777** a BLOB containing all zero bytes and N bytes in size.
5778**
5779** ^The sqlite3_result_double() interface sets the result from
5780** an application-defined function to be a floating point value specified
5781** by its 2nd argument.
5782**
5783** ^The sqlite3_result_error() and sqlite3_result_error16() functions
5784** cause the implemented SQL function to throw an exception.
5785** ^SQLite uses the string pointed to by the
5786** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
5787** as the text of an error message. ^SQLite interprets the error
5788** message string from sqlite3_result_error() as UTF-8. ^SQLite
5789** interprets the string from sqlite3_result_error16() as UTF-16 using
5790** the same [byte-order determination rules] as [sqlite3_bind_text16()].
5791** ^If the third parameter to sqlite3_result_error()
5792** or sqlite3_result_error16() is negative then SQLite takes as the error
5793** message all text up through the first zero character.
5794** ^If the third parameter to sqlite3_result_error() or
5795** sqlite3_result_error16() is non-negative then SQLite takes that many
5796** bytes (not characters) from the 2nd parameter as the error message.
5797** ^The sqlite3_result_error() and sqlite3_result_error16()
5798** routines make a private copy of the error message text before
5799** they return. Hence, the calling function can deallocate or
5800** modify the text after they return without harm.
5801** ^The sqlite3_result_error_code() function changes the error code
5802** returned by SQLite as a result of an error in a function. ^By default,
5803** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
5804** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
5805**
5806** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
5807** error indicating that a string or BLOB is too long to represent.
5808**
5809** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
5810** error indicating that a memory allocation failed.
5811**
5812** ^The sqlite3_result_int() interface sets the return value
5813** of the application-defined function to be the 32-bit signed integer
5814** value given in the 2nd argument.
5815** ^The sqlite3_result_int64() interface sets the return value
5816** of the application-defined function to be the 64-bit signed integer
5817** value given in the 2nd argument.
5818**
5819** ^The sqlite3_result_null() interface sets the return value
5820** of the application-defined function to be NULL.
5821**
5822** ^The sqlite3_result_text(), sqlite3_result_text16(),
5823** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
5824** set the return value of the application-defined function to be
5825** a text string which is represented as UTF-8, UTF-16 native byte order,
5826** UTF-16 little endian, or UTF-16 big endian, respectively.
5827** ^The sqlite3_result_text64() interface sets the return value of an
5828** application-defined function to be a text string in an encoding
5829** specified by the fifth (and last) parameter, which must be one
5830** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
5831** ^SQLite takes the text result from the application from
5832** the 2nd parameter of the sqlite3_result_text* interfaces.
5833** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5834** is negative, then SQLite takes result text from the 2nd parameter
5835** through the first zero character.
5836** ^If the 3rd parameter to the sqlite3_result_text* interfaces
5837** is non-negative, then as many bytes (not characters) of the text
5838** pointed to by the 2nd parameter are taken as the application-defined
5839** function result. If the 3rd parameter is non-negative, then it
5840** must be the byte offset into the string where the NUL terminator would
5841** appear if the string where NUL terminated. If any NUL characters occur
5842** in the string at a byte offset that is less than the value of the 3rd
5843** parameter, then the resulting string will contain embedded NULs and the
5844** result of expressions operating on strings with embedded NULs is undefined.
5845** ^If the 4th parameter to the sqlite3_result_text* interfaces
5846** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
5847** function as the destructor on the text or BLOB result when it has
5848** finished using that result.
5849** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
5850** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
5851** assumes that the text or BLOB result is in constant space and does not
5852** copy the content of the parameter nor call a destructor on the content
5853** when it has finished using that result.
5854** ^If the 4th parameter to the sqlite3_result_text* interfaces
5855** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
5856** then SQLite makes a copy of the result into space obtained
5857** from [sqlite3_malloc()] before it returns.
5858**
5859** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
5860** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
5861** when the encoding is not UTF8, if the input UTF16 begins with a
5862** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
5863** string and the rest of the string is interpreted according to the
5864** byte-order specified by the BOM. ^The byte-order specified by
5865** the BOM at the beginning of the text overrides the byte-order
5866** specified by the interface procedure. ^So, for example, if
5867** sqlite3_result_text16le() is invoked with text that begins
5868** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
5869** first two bytes of input are skipped and the remaining input
5870** is interpreted as UTF16BE text.
5871**
5872** ^For UTF16 input text to the sqlite3_result_text16(),
5873** sqlite3_result_text16be(), sqlite3_result_text16le(), and
5874** sqlite3_result_text64() routines, if the text contains invalid
5875** UTF16 characters, the invalid characters might be converted
5876** into the unicode replacement character, U+FFFD.
5877**
5878** ^The sqlite3_result_value() interface sets the result of
5879** the application-defined function to be a copy of the
5880** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
5881** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
5882** so that the [sqlite3_value] specified in the parameter may change or
5883** be deallocated after sqlite3_result_value() returns without harm.
5884** ^A [protected sqlite3_value] object may always be used where an
5885** [unprotected sqlite3_value] object is required, so either
5886** kind of [sqlite3_value] object can be used with this interface.
5887**
5888** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
5889** SQL NULL value, just like [sqlite3_result_null(C)], except that it
5890** also associates the host-language pointer P or type T with that
5891** NULL value such that the pointer can be retrieved within an
5892** [application-defined SQL function] using [sqlite3_value_pointer()].
5893** ^If the D parameter is not NULL, then it is a pointer to a destructor
5894** for the P parameter. ^SQLite invokes D with P as its only argument
5895** when SQLite is finished with P. The T parameter should be a static
5896** string and preferably a string literal. The sqlite3_result_pointer()
5897** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5898**
5899** If these routines are called from within the different thread
5900** than the one containing the application-defined function that received
5901** the [sqlite3_context] pointer, the results are undefined.
5902*/
5903SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
5904SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
5905 sqlite3_uint64,void(*)(void*));
5906SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
5907SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
5908SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
5909SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
5910SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
5911SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
5912SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
5913SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
5914SQLITE_API void sqlite3_result_null(sqlite3_context*);
5915SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
5916SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
5917 void(*)(void*), unsigned char encoding);
5918SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
5919SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
5920SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
5921SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
5922SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
5923SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
5924SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
5925
5926
5927/*
5928** CAPI3REF: Setting The Subtype Of An SQL Function
5929** METHOD: sqlite3_context
5930**
5931** The sqlite3_result_subtype(C,T) function causes the subtype of
5932** the result from the [application-defined SQL function] with
5933** [sqlite3_context] C to be the value T. Only the lower 8 bits
5934** of the subtype T are preserved in current versions of SQLite;
5935** higher order bits are discarded.
5936** The number of subtype bytes preserved by SQLite might increase
5937** in future releases of SQLite.
5938*/
5939SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
5940
5941/*
5942** CAPI3REF: Define New Collating Sequences
5943** METHOD: sqlite3
5944**
5945** ^These functions add, remove, or modify a [collation] associated
5946** with the [database connection] specified as the first argument.
5947**
5948** ^The name of the collation is a UTF-8 string
5949** for sqlite3_create_collation() and sqlite3_create_collation_v2()
5950** and a UTF-16 string in native byte order for sqlite3_create_collation16().
5951** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
5952** considered to be the same name.
5953**
5954** ^(The third argument (eTextRep) must be one of the constants:
5955** <ul>
5956** <li> [SQLITE_UTF8],
5957** <li> [SQLITE_UTF16LE],
5958** <li> [SQLITE_UTF16BE],
5959** <li> [SQLITE_UTF16], or
5960** <li> [SQLITE_UTF16_ALIGNED].
5961** </ul>)^
5962** ^The eTextRep argument determines the encoding of strings passed
5963** to the collating function callback, xCompare.
5964** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
5965** force strings to be UTF16 with native byte order.
5966** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
5967** on an even byte address.
5968**
5969** ^The fourth argument, pArg, is an application data pointer that is passed
5970** through as the first argument to the collating function callback.
5971**
5972** ^The fifth argument, xCompare, is a pointer to the collating function.
5973** ^Multiple collating functions can be registered using the same name but
5974** with different eTextRep parameters and SQLite will use whichever
5975** function requires the least amount of data transformation.
5976** ^If the xCompare argument is NULL then the collating function is
5977** deleted. ^When all collating functions having the same name are deleted,
5978** that collation is no longer usable.
5979**
5980** ^The collating function callback is invoked with a copy of the pArg
5981** application data pointer and with two strings in the encoding specified
5982** by the eTextRep argument. The two integer parameters to the collating
5983** function callback are the length of the two strings, in bytes. The collating
5984** function must return an integer that is negative, zero, or positive
5985** if the first string is less than, equal to, or greater than the second,
5986** respectively. A collating function must always return the same answer
5987** given the same inputs. If two or more collating functions are registered
5988** to the same collation name (using different eTextRep values) then all
5989** must give an equivalent answer when invoked with equivalent strings.
5990** The collating function must obey the following properties for all
5991** strings A, B, and C:
5992**
5993** <ol>
5994** <li> If A==B then B==A.
5995** <li> If A==B and B==C then A==C.
5996** <li> If A&lt;B THEN B&gt;A.
5997** <li> If A&lt;B and B&lt;C then A&lt;C.
5998** </ol>
5999**
6000** If a collating function fails any of the above constraints and that
6001** collating function is registered and used, then the behavior of SQLite
6002** is undefined.
6003**
6004** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6005** with the addition that the xDestroy callback is invoked on pArg when
6006** the collating function is deleted.
6007** ^Collating functions are deleted when they are overridden by later
6008** calls to the collation creation functions or when the
6009** [database connection] is closed using [sqlite3_close()].
6010**
6011** ^The xDestroy callback is <u>not</u> called if the
6012** sqlite3_create_collation_v2() function fails. Applications that invoke
6013** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6014** check the return code and dispose of the application data pointer
6015** themselves rather than expecting SQLite to deal with it for them.
6016** This is different from every other SQLite interface. The inconsistency
6017** is unfortunate but cannot be changed without breaking backwards
6018** compatibility.
6019**
6020** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6021*/
6022SQLITE_API int sqlite3_create_collation(
6023 sqlite3*,
6024 const char *zName,
6025 int eTextRep,
6026 void *pArg,
6027 int(*xCompare)(void*,int,const void*,int,const void*)
6028);
6029SQLITE_API int sqlite3_create_collation_v2(
6030 sqlite3*,
6031 const char *zName,
6032 int eTextRep,
6033 void *pArg,
6034 int(*xCompare)(void*,int,const void*,int,const void*),
6035 void(*xDestroy)(void*)
6036);
6037SQLITE_API int sqlite3_create_collation16(
6038 sqlite3*,
6039 const void *zName,
6040 int eTextRep,
6041 void *pArg,
6042 int(*xCompare)(void*,int,const void*,int,const void*)
6043);
6044
6045/*
6046** CAPI3REF: Collation Needed Callbacks
6047** METHOD: sqlite3
6048**
6049** ^To avoid having to register all collation sequences before a database
6050** can be used, a single callback function may be registered with the
6051** [database connection] to be invoked whenever an undefined collation
6052** sequence is required.
6053**
6054** ^If the function is registered using the sqlite3_collation_needed() API,
6055** then it is passed the names of undefined collation sequences as strings
6056** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6057** the names are passed as UTF-16 in machine native byte order.
6058** ^A call to either function replaces the existing collation-needed callback.
6059**
6060** ^(When the callback is invoked, the first argument passed is a copy
6061** of the second argument to sqlite3_collation_needed() or
6062** sqlite3_collation_needed16(). The second argument is the database
6063** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6064** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6065** sequence function required. The fourth parameter is the name of the
6066** required collation sequence.)^
6067**
6068** The callback function should register the desired collation using
6069** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6070** [sqlite3_create_collation_v2()].
6071*/
6072SQLITE_API int sqlite3_collation_needed(
6073 sqlite3*,
6074 void*,
6075 void(*)(void*,sqlite3*,int eTextRep,const char*)
6076);
6077SQLITE_API int sqlite3_collation_needed16(
6078 sqlite3*,
6079 void*,
6080 void(*)(void*,sqlite3*,int eTextRep,const void*)
6081);
6082
6083#ifdef SQLITE_ENABLE_CEROD
6084/*
6085** Specify the activation key for a CEROD database. Unless
6086** activated, none of the CEROD routines will work.
6087*/
6088SQLITE_API void sqlite3_activate_cerod(
6089 const char *zPassPhrase /* Activation phrase */
6090);
6091#endif
6092
6093/*
6094** CAPI3REF: Suspend Execution For A Short Time
6095**
6096** The sqlite3_sleep() function causes the current thread to suspend execution
6097** for at least a number of milliseconds specified in its parameter.
6098**
6099** If the operating system does not support sleep requests with
6100** millisecond time resolution, then the time will be rounded up to
6101** the nearest second. The number of milliseconds of sleep actually
6102** requested from the operating system is returned.
6103**
6104** ^SQLite implements this interface by calling the xSleep()
6105** method of the default [sqlite3_vfs] object. If the xSleep() method
6106** of the default VFS is not implemented correctly, or not implemented at
6107** all, then the behavior of sqlite3_sleep() may deviate from the description
6108** in the previous paragraphs.
6109*/
6110SQLITE_API int sqlite3_sleep(int);
6111
6112/*
6113** CAPI3REF: Name Of The Folder Holding Temporary Files
6114**
6115** ^(If this global variable is made to point to a string which is
6116** the name of a folder (a.k.a. directory), then all temporary files
6117** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6118** will be placed in that directory.)^ ^If this variable
6119** is a NULL pointer, then SQLite performs a search for an appropriate
6120** temporary file directory.
6121**
6122** Applications are strongly discouraged from using this global variable.
6123** It is required to set a temporary folder on Windows Runtime (WinRT).
6124** But for all other platforms, it is highly recommended that applications
6125** neither read nor write this variable. This global variable is a relic
6126** that exists for backwards compatibility of legacy applications and should
6127** be avoided in new projects.
6128**
6129** It is not safe to read or modify this variable in more than one
6130** thread at a time. It is not safe to read or modify this variable
6131** if a [database connection] is being used at the same time in a separate
6132** thread.
6133** It is intended that this variable be set once
6134** as part of process initialization and before any SQLite interface
6135** routines have been called and that this variable remain unchanged
6136** thereafter.
6137**
6138** ^The [temp_store_directory pragma] may modify this variable and cause
6139** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6140** the [temp_store_directory pragma] always assumes that any string
6141** that this variable points to is held in memory obtained from
6142** [sqlite3_malloc] and the pragma may attempt to free that memory
6143** using [sqlite3_free].
6144** Hence, if this variable is modified directly, either it should be
6145** made NULL or made to point to memory obtained from [sqlite3_malloc]
6146** or else the use of the [temp_store_directory pragma] should be avoided.
6147** Except when requested by the [temp_store_directory pragma], SQLite
6148** does not free the memory that sqlite3_temp_directory points to. If
6149** the application wants that memory to be freed, it must do
6150** so itself, taking care to only do so after all [database connection]
6151** objects have been destroyed.
6152**
6153** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6154** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6155** features that require the use of temporary files may fail. Here is an
6156** example of how to do this using C++ with the Windows Runtime:
6157**
6158** <blockquote><pre>
6159** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6160** &nbsp; TemporaryFolder->Path->Data();
6161** char zPathBuf&#91;MAX_PATH + 1&#93;;
6162** memset(zPathBuf, 0, sizeof(zPathBuf));
6163** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6164** &nbsp; NULL, NULL);
6165** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6166** </pre></blockquote>
6167*/
6168SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6169
6170/*
6171** CAPI3REF: Name Of The Folder Holding Database Files
6172**
6173** ^(If this global variable is made to point to a string which is
6174** the name of a folder (a.k.a. directory), then all database files
6175** specified with a relative pathname and created or accessed by
6176** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6177** to be relative to that directory.)^ ^If this variable is a NULL
6178** pointer, then SQLite assumes that all database files specified
6179** with a relative pathname are relative to the current directory
6180** for the process. Only the windows VFS makes use of this global
6181** variable; it is ignored by the unix VFS.
6182**
6183** Changing the value of this variable while a database connection is
6184** open can result in a corrupt database.
6185**
6186** It is not safe to read or modify this variable in more than one
6187** thread at a time. It is not safe to read or modify this variable
6188** if a [database connection] is being used at the same time in a separate
6189** thread.
6190** It is intended that this variable be set once
6191** as part of process initialization and before any SQLite interface
6192** routines have been called and that this variable remain unchanged
6193** thereafter.
6194**
6195** ^The [data_store_directory pragma] may modify this variable and cause
6196** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6197** the [data_store_directory pragma] always assumes that any string
6198** that this variable points to is held in memory obtained from
6199** [sqlite3_malloc] and the pragma may attempt to free that memory
6200** using [sqlite3_free].
6201** Hence, if this variable is modified directly, either it should be
6202** made NULL or made to point to memory obtained from [sqlite3_malloc]
6203** or else the use of the [data_store_directory pragma] should be avoided.
6204*/
6205SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6206
6207/*
6208** CAPI3REF: Win32 Specific Interface
6209**
6210** These interfaces are available only on Windows. The
6211** [sqlite3_win32_set_directory] interface is used to set the value associated
6212** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6213** zValue, depending on the value of the type parameter. The zValue parameter
6214** should be NULL to cause the previous value to be freed via [sqlite3_free];
6215** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6216** prior to being used. The [sqlite3_win32_set_directory] interface returns
6217** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6218** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6219** [sqlite3_data_directory] variable is intended to act as a replacement for
6220** the current directory on the sub-platforms of Win32 where that concept is
6221** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6222** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6223** sqlite3_win32_set_directory interface except the string parameter must be
6224** UTF-8 or UTF-16, respectively.
6225*/
6226SQLITE_API int sqlite3_win32_set_directory(
6227 unsigned long type, /* Identifier for directory being set or reset */
6228 void *zValue /* New value for directory being set or reset */
6229);
6230SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6231SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6232
6233/*
6234** CAPI3REF: Win32 Directory Types
6235**
6236** These macros are only available on Windows. They define the allowed values
6237** for the type argument to the [sqlite3_win32_set_directory] interface.
6238*/
6239#define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6240#define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6241
6242/*
6243** CAPI3REF: Test For Auto-Commit Mode
6244** KEYWORDS: {autocommit mode}
6245** METHOD: sqlite3
6246**
6247** ^The sqlite3_get_autocommit() interface returns non-zero or
6248** zero if the given database connection is or is not in autocommit mode,
6249** respectively. ^Autocommit mode is on by default.
6250** ^Autocommit mode is disabled by a [BEGIN] statement.
6251** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6252**
6253** If certain kinds of errors occur on a statement within a multi-statement
6254** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6255** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6256** transaction might be rolled back automatically. The only way to
6257** find out whether SQLite automatically rolled back the transaction after
6258** an error is to use this function.
6259**
6260** If another thread changes the autocommit status of the database
6261** connection while this routine is running, then the return value
6262** is undefined.
6263*/
6264SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6265
6266/*
6267** CAPI3REF: Find The Database Handle Of A Prepared Statement
6268** METHOD: sqlite3_stmt
6269**
6270** ^The sqlite3_db_handle interface returns the [database connection] handle
6271** to which a [prepared statement] belongs. ^The [database connection]
6272** returned by sqlite3_db_handle is the same [database connection]
6273** that was the first argument
6274** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6275** create the statement in the first place.
6276*/
6277SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6278
6279/*
6280** CAPI3REF: Return The Schema Name For A Database Connection
6281** METHOD: sqlite3
6282**
6283** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6284** for the N-th database on database connection D, or a NULL pointer of N is
6285** out of range. An N value of 0 means the main database file. An N of 1 is
6286** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6287** databases.
6288**
6289** Space to hold the string that is returned by sqlite3_db_name() is managed
6290** by SQLite itself. The string might be deallocated by any operation that
6291** changes the schema, including [ATTACH] or [DETACH] or calls to
6292** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6293** occur on a different thread. Applications that need to
6294** remember the string long-term should make their own copy. Applications that
6295** are accessing the same database connection simultaneously on multiple
6296** threads should mutex-protect calls to this API and should make their own
6297** private copy of the result prior to releasing the mutex.
6298*/
6299SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6300
6301/*
6302** CAPI3REF: Return The Filename For A Database Connection
6303** METHOD: sqlite3
6304**
6305** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6306** associated with database N of connection D.
6307** ^If there is no attached database N on the database
6308** connection D, or if database N is a temporary or in-memory database, then
6309** this function will return either a NULL pointer or an empty string.
6310**
6311** ^The string value returned by this routine is owned and managed by
6312** the database connection. ^The value will be valid until the database N
6313** is [DETACH]-ed or until the database connection closes.
6314**
6315** ^The filename returned by this function is the output of the
6316** xFullPathname method of the [VFS]. ^In other words, the filename
6317** will be an absolute pathname, even if the filename used
6318** to open the database originally was a URI or relative pathname.
6319**
6320** If the filename pointer returned by this routine is not NULL, then it
6321** can be used as the filename input parameter to these routines:
6322** <ul>
6323** <li> [sqlite3_uri_parameter()]
6324** <li> [sqlite3_uri_boolean()]
6325** <li> [sqlite3_uri_int64()]
6326** <li> [sqlite3_filename_database()]
6327** <li> [sqlite3_filename_journal()]
6328** <li> [sqlite3_filename_wal()]
6329** </ul>
6330*/
6331SQLITE_API const char *sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6332
6333/*
6334** CAPI3REF: Determine if a database is read-only
6335** METHOD: sqlite3
6336**
6337** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6338** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6339** the name of a database on connection D.
6340*/
6341SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6342
6343/*
6344** CAPI3REF: Determine the transaction state of a database
6345** METHOD: sqlite3
6346**
6347** ^The sqlite3_txn_state(D,S) interface returns the current
6348** [transaction state] of schema S in database connection D. ^If S is NULL,
6349** then the highest transaction state of any schema on database connection D
6350** is returned. Transaction states are (in order of lowest to highest):
6351** <ol>
6352** <li value="0"> SQLITE_TXN_NONE
6353** <li value="1"> SQLITE_TXN_READ
6354** <li value="2"> SQLITE_TXN_WRITE
6355** </ol>
6356** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6357** a valid schema, then -1 is returned.
6358*/
6359SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6360
6361/*
6362** CAPI3REF: Allowed return values from [sqlite3_txn_state()]
6363** KEYWORDS: {transaction state}
6364**
6365** These constants define the current transaction state of a database file.
6366** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6367** constants in order to describe the transaction state of schema S
6368** in [database connection] D.
6369**
6370** <dl>
6371** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6372** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6373** pending.</dd>
6374**
6375** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6376** <dd>The SQLITE_TXN_READ state means that the database is currently
6377** in a read transaction. Content has been read from the database file
6378** but nothing in the database file has changed. The transaction state
6379** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
6380** no other conflicting concurrent write transactions. The transaction
6381** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6382** [COMMIT].</dd>
6383**
6384** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6385** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6386** in a write transaction. Content has been written to the database file
6387** but has not yet committed. The transaction state will change to
6388** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6389*/
6390#define SQLITE_TXN_NONE 0
6391#define SQLITE_TXN_READ 1
6392#define SQLITE_TXN_WRITE 2
6393
6394/*
6395** CAPI3REF: Find the next prepared statement
6396** METHOD: sqlite3
6397**
6398** ^This interface returns a pointer to the next [prepared statement] after
6399** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6400** then this interface returns a pointer to the first prepared statement
6401** associated with the database connection pDb. ^If no prepared statement
6402** satisfies the conditions of this routine, it returns NULL.
6403**
6404** The [database connection] pointer D in a call to
6405** [sqlite3_next_stmt(D,S)] must refer to an open database
6406** connection and in particular must not be a NULL pointer.
6407*/
6408SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6409
6410/*
6411** CAPI3REF: Commit And Rollback Notification Callbacks
6412** METHOD: sqlite3
6413**
6414** ^The sqlite3_commit_hook() interface registers a callback
6415** function to be invoked whenever a transaction is [COMMIT | committed].
6416** ^Any callback set by a previous call to sqlite3_commit_hook()
6417** for the same database connection is overridden.
6418** ^The sqlite3_rollback_hook() interface registers a callback
6419** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6420** ^Any callback set by a previous call to sqlite3_rollback_hook()
6421** for the same database connection is overridden.
6422** ^The pArg argument is passed through to the callback.
6423** ^If the callback on a commit hook function returns non-zero,
6424** then the commit is converted into a rollback.
6425**
6426** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6427** return the P argument from the previous call of the same function
6428** on the same [database connection] D, or NULL for
6429** the first call for each function on D.
6430**
6431** The commit and rollback hook callbacks are not reentrant.
6432** The callback implementation must not do anything that will modify
6433** the database connection that invoked the callback. Any actions
6434** to modify the database connection must be deferred until after the
6435** completion of the [sqlite3_step()] call that triggered the commit
6436** or rollback hook in the first place.
6437** Note that running any other SQL statements, including SELECT statements,
6438** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6439** the database connections for the meaning of "modify" in this paragraph.
6440**
6441** ^Registering a NULL function disables the callback.
6442**
6443** ^When the commit hook callback routine returns zero, the [COMMIT]
6444** operation is allowed to continue normally. ^If the commit hook
6445** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6446** ^The rollback hook is invoked on a rollback that results from a commit
6447** hook returning non-zero, just as it would be with any other rollback.
6448**
6449** ^For the purposes of this API, a transaction is said to have been
6450** rolled back if an explicit "ROLLBACK" statement is executed, or
6451** an error or constraint causes an implicit rollback to occur.
6452** ^The rollback callback is not invoked if a transaction is
6453** automatically rolled back because the database connection is closed.
6454**
6455** See also the [sqlite3_update_hook()] interface.
6456*/
6457SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6458SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6459
6460/*
6461** CAPI3REF: Autovacuum Compaction Amount Callback
6462** METHOD: sqlite3
6463**
6464** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
6465** function C that is invoked prior to each autovacuum of the database
6466** file. ^The callback is passed a copy of the generic data pointer (P),
6467** the schema-name of the attached database that is being autovacuumed,
6468** the the size of the database file in pages, the number of free pages,
6469** and the number of bytes per page, respectively. The callback should
6470** return the number of free pages that should be removed by the
6471** autovacuum. ^If the callback returns zero, then no autovacuum happens.
6472** ^If the value returned is greater than or equal to the number of
6473** free pages, then a complete autovacuum happens.
6474**
6475** <p>^If there are multiple ATTACH-ed database files that are being
6476** modified as part of a transaction commit, then the autovacuum pages
6477** callback is invoked separately for each file.
6478**
6479** <p><b>The callback is not reentrant.</b> The callback function should
6480** not attempt to invoke any other SQLite interface. If it does, bad
6481** things may happen, including segmentation faults and corrupt database
6482** files. The callback function should be a simple function that
6483** does some arithmetic on its input parameters and returns a result.
6484**
6485** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
6486** destructor for the P parameter. ^If X is not NULL, then X(P) is
6487** invoked whenever the database connection closes or when the callback
6488** is overwritten by another invocation of sqlite3_autovacuum_pages().
6489**
6490** <p>^There is only one autovacuum pages callback per database connection.
6491** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
6492** previous invocations for that database connection. ^If the callback
6493** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
6494** then the autovacuum steps callback is cancelled. The return value
6495** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
6496** be some other error code if something goes wrong. The current
6497** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
6498** return codes might be added in future releases.
6499**
6500** <p>If no autovacuum pages callback is specified (the usual case) or
6501** a NULL pointer is provided for the callback,
6502** then the default behavior is to vacuum all free pages. So, in other
6503** words, the default behavior is the same as if the callback function
6504** were something like this:
6505**
6506** <blockquote><pre>
6507** &nbsp; unsigned int demonstration_autovac_pages_callback(
6508** &nbsp; void *pClientData,
6509** &nbsp; const char *zSchema,
6510** &nbsp; unsigned int nDbPage,
6511** &nbsp; unsigned int nFreePage,
6512** &nbsp; unsigned int nBytePerPage
6513** &nbsp; ){
6514** &nbsp; return nFreePage;
6515** &nbsp; }
6516** </pre></blockquote>
6517*/
6518SQLITE_API int sqlite3_autovacuum_pages(
6519 sqlite3 *db,
6520 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
6521 void*,
6522 void(*)(void*)
6523);
6524
6525
6526/*
6527** CAPI3REF: Data Change Notification Callbacks
6528** METHOD: sqlite3
6529**
6530** ^The sqlite3_update_hook() interface registers a callback function
6531** with the [database connection] identified by the first argument
6532** to be invoked whenever a row is updated, inserted or deleted in
6533** a [rowid table].
6534** ^Any callback set by a previous call to this function
6535** for the same database connection is overridden.
6536**
6537** ^The second argument is a pointer to the function to invoke when a
6538** row is updated, inserted or deleted in a rowid table.
6539** ^The first argument to the callback is a copy of the third argument
6540** to sqlite3_update_hook().
6541** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6542** or [SQLITE_UPDATE], depending on the operation that caused the callback
6543** to be invoked.
6544** ^The third and fourth arguments to the callback contain pointers to the
6545** database and table name containing the affected row.
6546** ^The final callback parameter is the [rowid] of the row.
6547** ^In the case of an update, this is the [rowid] after the update takes place.
6548**
6549** ^(The update hook is not invoked when internal system tables are
6550** modified (i.e. sqlite_sequence).)^
6551** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
6552**
6553** ^In the current implementation, the update hook
6554** is not invoked when conflicting rows are deleted because of an
6555** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6556** invoked when rows are deleted using the [truncate optimization].
6557** The exceptions defined in this paragraph might change in a future
6558** release of SQLite.
6559**
6560** The update hook implementation must not do anything that will modify
6561** the database connection that invoked the update hook. Any actions
6562** to modify the database connection must be deferred until after the
6563** completion of the [sqlite3_step()] call that triggered the update hook.
6564** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6565** database connections for the meaning of "modify" in this paragraph.
6566**
6567** ^The sqlite3_update_hook(D,C,P) function
6568** returns the P argument from the previous call
6569** on the same [database connection] D, or NULL for
6570** the first call on D.
6571**
6572** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6573** and [sqlite3_preupdate_hook()] interfaces.
6574*/
6575SQLITE_API void *sqlite3_update_hook(
6576 sqlite3*,
6577 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6578 void*
6579);
6580
6581/*
6582** CAPI3REF: Enable Or Disable Shared Pager Cache
6583**
6584** ^(This routine enables or disables the sharing of the database cache
6585** and schema data structures between [database connection | connections]
6586** to the same database. Sharing is enabled if the argument is true
6587** and disabled if the argument is false.)^
6588**
6589** ^Cache sharing is enabled and disabled for an entire process.
6590** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6591** In prior versions of SQLite,
6592** sharing was enabled or disabled for each thread separately.
6593**
6594** ^(The cache sharing mode set by this interface effects all subsequent
6595** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
6596** Existing database connections continue to use the sharing mode
6597** that was in effect at the time they were opened.)^
6598**
6599** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6600** successfully. An [error code] is returned otherwise.)^
6601**
6602** ^Shared cache is disabled by default. It is recommended that it stay
6603** that way. In other words, do not use this routine. This interface
6604** continues to be provided for historical compatibility, but its use is
6605** discouraged. Any use of shared cache is discouraged. If shared cache
6606** must be used, it is recommended that shared cache only be enabled for
6607** individual database connections using the [sqlite3_open_v2()] interface
6608** with the [SQLITE_OPEN_SHAREDCACHE] flag.
6609**
6610** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
6611** and will always return SQLITE_MISUSE. On those systems,
6612** shared cache mode should be enabled per-database connection via
6613** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6614**
6615** This interface is threadsafe on processors where writing a
6616** 32-bit integer is atomic.
6617**
6618** See Also: [SQLite Shared-Cache Mode]
6619*/
6620SQLITE_API int sqlite3_enable_shared_cache(int);
6621
6622/*
6623** CAPI3REF: Attempt To Free Heap Memory
6624**
6625** ^The sqlite3_release_memory() interface attempts to free N bytes
6626** of heap memory by deallocating non-essential memory allocations
6627** held by the database library. Memory used to cache database
6628** pages to improve performance is an example of non-essential memory.
6629** ^sqlite3_release_memory() returns the number of bytes actually freed,
6630** which might be more or less than the amount requested.
6631** ^The sqlite3_release_memory() routine is a no-op returning zero
6632** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6633**
6634** See also: [sqlite3_db_release_memory()]
6635*/
6636SQLITE_API int sqlite3_release_memory(int);
6637
6638/*
6639** CAPI3REF: Free Memory Used By A Database Connection
6640** METHOD: sqlite3
6641**
6642** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6643** memory as possible from database connection D. Unlike the
6644** [sqlite3_release_memory()] interface, this interface is in effect even
6645** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6646** omitted.
6647**
6648** See also: [sqlite3_release_memory()]
6649*/
6650SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6651
6652/*
6653** CAPI3REF: Impose A Limit On Heap Size
6654**
6655** These interfaces impose limits on the amount of heap memory that will be
6656** by all database connections within a single process.
6657**
6658** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
6659** soft limit on the amount of heap memory that may be allocated by SQLite.
6660** ^SQLite strives to keep heap memory utilization below the soft heap
6661** limit by reducing the number of pages held in the page cache
6662** as heap memory usages approaches the limit.
6663** ^The soft heap limit is "soft" because even though SQLite strives to stay
6664** below the limit, it will exceed the limit rather than generate
6665** an [SQLITE_NOMEM] error. In other words, the soft heap limit
6666** is advisory only.
6667**
6668** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
6669** N bytes on the amount of memory that will be allocated. ^The
6670** sqlite3_hard_heap_limit64(N) interface is similar to
6671** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
6672** when the hard heap limit is reached.
6673**
6674** ^The return value from both sqlite3_soft_heap_limit64() and
6675** sqlite3_hard_heap_limit64() is the size of
6676** the heap limit prior to the call, or negative in the case of an
6677** error. ^If the argument N is negative
6678** then no change is made to the heap limit. Hence, the current
6679** size of heap limits can be determined by invoking
6680** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
6681**
6682** ^Setting the heap limits to zero disables the heap limiter mechanism.
6683**
6684** ^The soft heap limit may not be greater than the hard heap limit.
6685** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
6686** is invoked with a value of N that is greater than the hard heap limit,
6687** the the soft heap limit is set to the value of the hard heap limit.
6688** ^The soft heap limit is automatically enabled whenever the hard heap
6689** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
6690** the soft heap limit is outside the range of 1..N, then the soft heap
6691** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
6692** hard heap limit is enabled makes the soft heap limit equal to the
6693** hard heap limit.
6694**
6695** The memory allocation limits can also be adjusted using
6696** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
6697**
6698** ^(The heap limits are not enforced in the current implementation
6699** if one or more of following conditions are true:
6700**
6701** <ul>
6702** <li> The limit value is set to zero.
6703** <li> Memory accounting is disabled using a combination of the
6704** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
6705** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
6706** <li> An alternative page cache implementation is specified using
6707** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
6708** <li> The page cache allocates from its own memory pool supplied
6709** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
6710** from the heap.
6711** </ul>)^
6712**
6713** The circumstances under which SQLite will enforce the heap limits may
6714** changes in future releases of SQLite.
6715*/
6716SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
6717SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
6718
6719/*
6720** CAPI3REF: Deprecated Soft Heap Limit Interface
6721** DEPRECATED
6722**
6723** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
6724** interface. This routine is provided for historical compatibility
6725** only. All new applications should use the
6726** [sqlite3_soft_heap_limit64()] interface rather than this one.
6727*/
6728SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
6729
6730
6731/*
6732** CAPI3REF: Extract Metadata About A Column Of A Table
6733** METHOD: sqlite3
6734**
6735** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
6736** information about column C of table T in database D
6737** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
6738** interface returns SQLITE_OK and fills in the non-NULL pointers in
6739** the final five arguments with appropriate values if the specified
6740** column exists. ^The sqlite3_table_column_metadata() interface returns
6741** SQLITE_ERROR if the specified column does not exist.
6742** ^If the column-name parameter to sqlite3_table_column_metadata() is a
6743** NULL pointer, then this routine simply checks for the existence of the
6744** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
6745** does not. If the table name parameter T in a call to
6746** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
6747** undefined behavior.
6748**
6749** ^The column is identified by the second, third and fourth parameters to
6750** this function. ^(The second parameter is either the name of the database
6751** (i.e. "main", "temp", or an attached database) containing the specified
6752** table or NULL.)^ ^If it is NULL, then all attached databases are searched
6753** for the table using the same algorithm used by the database engine to
6754** resolve unqualified table references.
6755**
6756** ^The third and fourth parameters to this function are the table and column
6757** name of the desired column, respectively.
6758**
6759** ^Metadata is returned by writing to the memory locations passed as the 5th
6760** and subsequent parameters to this function. ^Any of these arguments may be
6761** NULL, in which case the corresponding element of metadata is omitted.
6762**
6763** ^(<blockquote>
6764** <table border="1">
6765** <tr><th> Parameter <th> Output<br>Type <th> Description
6766**
6767** <tr><td> 5th <td> const char* <td> Data type
6768** <tr><td> 6th <td> const char* <td> Name of default collation sequence
6769** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
6770** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
6771** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
6772** </table>
6773** </blockquote>)^
6774**
6775** ^The memory pointed to by the character pointers returned for the
6776** declaration type and collation sequence is valid until the next
6777** call to any SQLite API function.
6778**
6779** ^If the specified table is actually a view, an [error code] is returned.
6780**
6781** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
6782** is not a [WITHOUT ROWID] table and an
6783** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
6784** parameters are set for the explicitly declared column. ^(If there is no
6785** [INTEGER PRIMARY KEY] column, then the outputs
6786** for the [rowid] are set as follows:
6787**
6788** <pre>
6789** data type: "INTEGER"
6790** collation sequence: "BINARY"
6791** not null: 0
6792** primary key: 1
6793** auto increment: 0
6794** </pre>)^
6795**
6796** ^This function causes all database schemas to be read from disk and
6797** parsed, if that has not already been done, and returns an error if
6798** any errors are encountered while loading the schema.
6799*/
6800SQLITE_API int sqlite3_table_column_metadata(
6801 sqlite3 *db, /* Connection handle */
6802 const char *zDbName, /* Database name or NULL */
6803 const char *zTableName, /* Table name */
6804 const char *zColumnName, /* Column name */
6805 char const **pzDataType, /* OUTPUT: Declared data type */
6806 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
6807 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
6808 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
6809 int *pAutoinc /* OUTPUT: True if column is auto-increment */
6810);
6811
6812/*
6813** CAPI3REF: Load An Extension
6814** METHOD: sqlite3
6815**
6816** ^This interface loads an SQLite extension library from the named file.
6817**
6818** ^The sqlite3_load_extension() interface attempts to load an
6819** [SQLite extension] library contained in the file zFile. If
6820** the file cannot be loaded directly, attempts are made to load
6821** with various operating-system specific extensions added.
6822** So for example, if "samplelib" cannot be loaded, then names like
6823** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
6824** be tried also.
6825**
6826** ^The entry point is zProc.
6827** ^(zProc may be 0, in which case SQLite will try to come up with an
6828** entry point name on its own. It first tries "sqlite3_extension_init".
6829** If that does not work, it constructs a name "sqlite3_X_init" where the
6830** X is consists of the lower-case equivalent of all ASCII alphabetic
6831** characters in the filename from the last "/" to the first following
6832** "." and omitting any initial "lib".)^
6833** ^The sqlite3_load_extension() interface returns
6834** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
6835** ^If an error occurs and pzErrMsg is not 0, then the
6836** [sqlite3_load_extension()] interface shall attempt to
6837** fill *pzErrMsg with error message text stored in memory
6838** obtained from [sqlite3_malloc()]. The calling function
6839** should free this memory by calling [sqlite3_free()].
6840**
6841** ^Extension loading must be enabled using
6842** [sqlite3_enable_load_extension()] or
6843** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
6844** prior to calling this API,
6845** otherwise an error will be returned.
6846**
6847** <b>Security warning:</b> It is recommended that the
6848** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
6849** interface. The use of the [sqlite3_enable_load_extension()] interface
6850** should be avoided. This will keep the SQL function [load_extension()]
6851** disabled and prevent SQL injections from giving attackers
6852** access to extension loading capabilities.
6853**
6854** See also the [load_extension() SQL function].
6855*/
6856SQLITE_API int sqlite3_load_extension(
6857 sqlite3 *db, /* Load the extension into this database connection */
6858 const char *zFile, /* Name of the shared library containing extension */
6859 const char *zProc, /* Entry point. Derived from zFile if 0 */
6860 char **pzErrMsg /* Put error message here if not 0 */
6861);
6862
6863/*
6864** CAPI3REF: Enable Or Disable Extension Loading
6865** METHOD: sqlite3
6866**
6867** ^So as not to open security holes in older applications that are
6868** unprepared to deal with [extension loading], and as a means of disabling
6869** [extension loading] while evaluating user-entered SQL, the following API
6870** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
6871**
6872** ^Extension loading is off by default.
6873** ^Call the sqlite3_enable_load_extension() routine with onoff==1
6874** to turn extension loading on and call it with onoff==0 to turn
6875** it back off again.
6876**
6877** ^This interface enables or disables both the C-API
6878** [sqlite3_load_extension()] and the SQL function [load_extension()].
6879** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
6880** to enable or disable only the C-API.)^
6881**
6882** <b>Security warning:</b> It is recommended that extension loading
6883** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
6884** rather than this interface, so the [load_extension()] SQL function
6885** remains disabled. This will prevent SQL injections from giving attackers
6886** access to extension loading capabilities.
6887*/
6888SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
6889
6890/*
6891** CAPI3REF: Automatically Load Statically Linked Extensions
6892**
6893** ^This interface causes the xEntryPoint() function to be invoked for
6894** each new [database connection] that is created. The idea here is that
6895** xEntryPoint() is the entry point for a statically linked [SQLite extension]
6896** that is to be automatically loaded into all new database connections.
6897**
6898** ^(Even though the function prototype shows that xEntryPoint() takes
6899** no arguments and returns void, SQLite invokes xEntryPoint() with three
6900** arguments and expects an integer result as if the signature of the
6901** entry point where as follows:
6902**
6903** <blockquote><pre>
6904** &nbsp; int xEntryPoint(
6905** &nbsp; sqlite3 *db,
6906** &nbsp; const char **pzErrMsg,
6907** &nbsp; const struct sqlite3_api_routines *pThunk
6908** &nbsp; );
6909** </pre></blockquote>)^
6910**
6911** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
6912** point to an appropriate error message (obtained from [sqlite3_mprintf()])
6913** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
6914** is NULL before calling the xEntryPoint(). ^SQLite will invoke
6915** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
6916** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
6917** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
6918**
6919** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
6920** on the list of automatic extensions is a harmless no-op. ^No entry point
6921** will be called more than once for each database connection that is opened.
6922**
6923** See also: [sqlite3_reset_auto_extension()]
6924** and [sqlite3_cancel_auto_extension()]
6925*/
6926SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
6927
6928/*
6929** CAPI3REF: Cancel Automatic Extension Loading
6930**
6931** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
6932** initialization routine X that was registered using a prior call to
6933** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
6934** routine returns 1 if initialization routine X was successfully
6935** unregistered and it returns 0 if X was not on the list of initialization
6936** routines.
6937*/
6938SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
6939
6940/*
6941** CAPI3REF: Reset Automatic Extension Loading
6942**
6943** ^This interface disables all automatic extensions previously
6944** registered using [sqlite3_auto_extension()].
6945*/
6946SQLITE_API void sqlite3_reset_auto_extension(void);
6947
6948/*
6949** The interface to the virtual-table mechanism is currently considered
6950** to be experimental. The interface might change in incompatible ways.
6951** If this is a problem for you, do not use the interface at this time.
6952**
6953** When the virtual-table mechanism stabilizes, we will declare the
6954** interface fixed, support it indefinitely, and remove this comment.
6955*/
6956
6957/*
6958** Structures used by the virtual table interface
6959*/
6960typedef struct sqlite3_vtab sqlite3_vtab;
6961typedef struct sqlite3_index_info sqlite3_index_info;
6962typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
6963typedef struct sqlite3_module sqlite3_module;
6964
6965/*
6966** CAPI3REF: Virtual Table Object
6967** KEYWORDS: sqlite3_module {virtual table module}
6968**
6969** This structure, sometimes called a "virtual table module",
6970** defines the implementation of a [virtual table].
6971** This structure consists mostly of methods for the module.
6972**
6973** ^A virtual table module is created by filling in a persistent
6974** instance of this structure and passing a pointer to that instance
6975** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
6976** ^The registration remains valid until it is replaced by a different
6977** module or until the [database connection] closes. The content
6978** of this structure must not change while it is registered with
6979** any database connection.
6980*/
6981struct sqlite3_module {
6982 int iVersion;
6983 int (*xCreate)(sqlite3*, void *pAux,
6984 int argc, const char *const*argv,
6985 sqlite3_vtab **ppVTab, char**);
6986 int (*xConnect)(sqlite3*, void *pAux,
6987 int argc, const char *const*argv,
6988 sqlite3_vtab **ppVTab, char**);
6989 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
6990 int (*xDisconnect)(sqlite3_vtab *pVTab);
6991 int (*xDestroy)(sqlite3_vtab *pVTab);
6992 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
6993 int (*xClose)(sqlite3_vtab_cursor*);
6994 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
6995 int argc, sqlite3_value **argv);
6996 int (*xNext)(sqlite3_vtab_cursor*);
6997 int (*xEof)(sqlite3_vtab_cursor*);
6998 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
6999 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7000 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7001 int (*xBegin)(sqlite3_vtab *pVTab);
7002 int (*xSync)(sqlite3_vtab *pVTab);
7003 int (*xCommit)(sqlite3_vtab *pVTab);
7004 int (*xRollback)(sqlite3_vtab *pVTab);
7005 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7006 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7007 void **ppArg);
7008 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7009 /* The methods above are in version 1 of the sqlite_module object. Those
7010 ** below are for version 2 and greater. */
7011 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7012 int (*xRelease)(sqlite3_vtab *pVTab, int);
7013 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7014 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7015 ** Those below are for version 3 and greater. */
7016 int (*xShadowName)(const char*);
7017};
7018
7019/*
7020** CAPI3REF: Virtual Table Indexing Information
7021** KEYWORDS: sqlite3_index_info
7022**
7023** The sqlite3_index_info structure and its substructures is used as part
7024** of the [virtual table] interface to
7025** pass information into and receive the reply from the [xBestIndex]
7026** method of a [virtual table module]. The fields under **Inputs** are the
7027** inputs to xBestIndex and are read-only. xBestIndex inserts its
7028** results into the **Outputs** fields.
7029**
7030** ^(The aConstraint[] array records WHERE clause constraints of the form:
7031**
7032** <blockquote>column OP expr</blockquote>
7033**
7034** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
7035** stored in aConstraint[].op using one of the
7036** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7037** ^(The index of the column is stored in
7038** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7039** expr on the right-hand side can be evaluated (and thus the constraint
7040** is usable) and false if it cannot.)^
7041**
7042** ^The optimizer automatically inverts terms of the form "expr OP column"
7043** and makes other simplifications to the WHERE clause in an attempt to
7044** get as many WHERE clause terms into the form shown above as possible.
7045** ^The aConstraint[] array only reports WHERE clause terms that are
7046** relevant to the particular virtual table being queried.
7047**
7048** ^Information about the ORDER BY clause is stored in aOrderBy[].
7049** ^Each term of aOrderBy records a column of the ORDER BY clause.
7050**
7051** The colUsed field indicates which columns of the virtual table may be
7052** required by the current scan. Virtual table columns are numbered from
7053** zero in the order in which they appear within the CREATE TABLE statement
7054** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7055** the corresponding bit is set within the colUsed mask if the column may be
7056** required by SQLite. If the table has at least 64 columns and any column
7057** to the right of the first 63 is required, then bit 63 of colUsed is also
7058** set. In other words, column iCol may be required if the expression
7059** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7060** non-zero.
7061**
7062** The [xBestIndex] method must fill aConstraintUsage[] with information
7063** about what parameters to pass to xFilter. ^If argvIndex>0 then
7064** the right-hand side of the corresponding aConstraint[] is evaluated
7065** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7066** is true, then the constraint is assumed to be fully handled by the
7067** virtual table and might not be checked again by the byte code.)^ ^(The
7068** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7069** is left in its default setting of false, the constraint will always be
7070** checked separately in byte code. If the omit flag is change to true, then
7071** the constraint may or may not be checked in byte code. In other words,
7072** when the omit flag is true there is no guarantee that the constraint will
7073** not be checked again using byte code.)^
7074**
7075** ^The idxNum and idxPtr values are recorded and passed into the
7076** [xFilter] method.
7077** ^[sqlite3_free()] is used to free idxPtr if and only if
7078** needToFreeIdxPtr is true.
7079**
7080** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7081** the correct order to satisfy the ORDER BY clause so that no separate
7082** sorting step is required.
7083**
7084** ^The estimatedCost value is an estimate of the cost of a particular
7085** strategy. A cost of N indicates that the cost of the strategy is similar
7086** to a linear scan of an SQLite table with N rows. A cost of log(N)
7087** indicates that the expense of the operation is similar to that of a
7088** binary search on a unique indexed field of an SQLite table with N rows.
7089**
7090** ^The estimatedRows value is an estimate of the number of rows that
7091** will be returned by the strategy.
7092**
7093** The xBestIndex method may optionally populate the idxFlags field with a
7094** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
7095** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
7096** assumes that the strategy may visit at most one row.
7097**
7098** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7099** SQLite also assumes that if a call to the xUpdate() method is made as
7100** part of the same statement to delete or update a virtual table row and the
7101** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7102** any database changes. In other words, if the xUpdate() returns
7103** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7104** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7105** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7106** the xUpdate method are automatically rolled back by SQLite.
7107**
7108** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7109** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7110** If a virtual table extension is
7111** used with an SQLite version earlier than 3.8.2, the results of attempting
7112** to read or write the estimatedRows field are undefined (but are likely
7113** to include crashing the application). The estimatedRows field should
7114** therefore only be used if [sqlite3_libversion_number()] returns a
7115** value greater than or equal to 3008002. Similarly, the idxFlags field
7116** was added for [version 3.9.0] ([dateof:3.9.0]).
7117** It may therefore only be used if
7118** sqlite3_libversion_number() returns a value greater than or equal to
7119** 3009000.
7120*/
7121struct sqlite3_index_info {
7122 /* Inputs */
7123 int nConstraint; /* Number of entries in aConstraint */
7124 struct sqlite3_index_constraint {
7125 int iColumn; /* Column constrained. -1 for ROWID */
7126 unsigned char op; /* Constraint operator */
7127 unsigned char usable; /* True if this constraint is usable */
7128 int iTermOffset; /* Used internally - xBestIndex should ignore */
7129 } *aConstraint; /* Table of WHERE clause constraints */
7130 int nOrderBy; /* Number of terms in the ORDER BY clause */
7131 struct sqlite3_index_orderby {
7132 int iColumn; /* Column number */
7133 unsigned char desc; /* True for DESC. False for ASC. */
7134 } *aOrderBy; /* The ORDER BY clause */
7135 /* Outputs */
7136 struct sqlite3_index_constraint_usage {
7137 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7138 unsigned char omit; /* Do not code a test for this constraint */
7139 } *aConstraintUsage;
7140 int idxNum; /* Number used to identify the index */
7141 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7142 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7143 int orderByConsumed; /* True if output is already ordered */
7144 double estimatedCost; /* Estimated cost of using this index */
7145 /* Fields below are only available in SQLite 3.8.2 and later */
7146 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7147 /* Fields below are only available in SQLite 3.9.0 and later */
7148 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7149 /* Fields below are only available in SQLite 3.10.0 and later */
7150 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7151};
7152
7153/*
7154** CAPI3REF: Virtual Table Scan Flags
7155**
7156** Virtual table implementations are allowed to set the
7157** [sqlite3_index_info].idxFlags field to some combination of
7158** these bits.
7159*/
7160#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
7161
7162/*
7163** CAPI3REF: Virtual Table Constraint Operator Codes
7164**
7165** These macros define the allowed values for the
7166** [sqlite3_index_info].aConstraint[].op field. Each value represents
7167** an operator that is part of a constraint term in the WHERE clause of
7168** a query that uses a [virtual table].
7169**
7170** ^The left-hand operand of the operator is given by the corresponding
7171** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7172** operand is the rowid.
7173** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7174** operators have no left-hand operand, and so for those operators the
7175** corresponding aConstraint[].iColumn is meaningless and should not be
7176** used.
7177**
7178** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7179** value 255 are reserved to represent functions that are overloaded
7180** by the [xFindFunction|xFindFunction method] of the virtual table
7181** implementation.
7182**
7183** The right-hand operands for each constraint might be accessible using
7184** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7185** operand is only available if it appears as a single constant literal
7186** in the input SQL. If the right-hand operand is another column or an
7187** expression (even a constant expression) or a parameter, then the
7188** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7189** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7190** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7191** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7192** always return SQLITE_NOTFOUND.
7193**
7194** The collating sequence to be used for comparison can be found using
7195** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7196** tables, the collating sequence of constraints does not matter (for example
7197** because the constraints are numeric) and so the sqlite3_vtab_collation()
7198** interface is no commonly needed.
7199*/
7200#define SQLITE_INDEX_CONSTRAINT_EQ 2
7201#define SQLITE_INDEX_CONSTRAINT_GT 4
7202#define SQLITE_INDEX_CONSTRAINT_LE 8
7203#define SQLITE_INDEX_CONSTRAINT_LT 16
7204#define SQLITE_INDEX_CONSTRAINT_GE 32
7205#define SQLITE_INDEX_CONSTRAINT_MATCH 64
7206#define SQLITE_INDEX_CONSTRAINT_LIKE 65
7207#define SQLITE_INDEX_CONSTRAINT_GLOB 66
7208#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7209#define SQLITE_INDEX_CONSTRAINT_NE 68
7210#define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7211#define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7212#define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7213#define SQLITE_INDEX_CONSTRAINT_IS 72
7214#define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7215#define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7216#define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7217
7218/*
7219** CAPI3REF: Register A Virtual Table Implementation
7220** METHOD: sqlite3
7221**
7222** ^These routines are used to register a new [virtual table module] name.
7223** ^Module names must be registered before
7224** creating a new [virtual table] using the module and before using a
7225** preexisting [virtual table] for the module.
7226**
7227** ^The module name is registered on the [database connection] specified
7228** by the first parameter. ^The name of the module is given by the
7229** second parameter. ^The third parameter is a pointer to
7230** the implementation of the [virtual table module]. ^The fourth
7231** parameter is an arbitrary client data pointer that is passed through
7232** into the [xCreate] and [xConnect] methods of the virtual table module
7233** when a new virtual table is be being created or reinitialized.
7234**
7235** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7236** is a pointer to a destructor for the pClientData. ^SQLite will
7237** invoke the destructor function (if it is not NULL) when SQLite
7238** no longer needs the pClientData pointer. ^The destructor will also
7239** be invoked if the call to sqlite3_create_module_v2() fails.
7240** ^The sqlite3_create_module()
7241** interface is equivalent to sqlite3_create_module_v2() with a NULL
7242** destructor.
7243**
7244** ^If the third parameter (the pointer to the sqlite3_module object) is
7245** NULL then no new module is created and any existing modules with the
7246** same name are dropped.
7247**
7248** See also: [sqlite3_drop_modules()]
7249*/
7250SQLITE_API int sqlite3_create_module(
7251 sqlite3 *db, /* SQLite connection to register module with */
7252 const char *zName, /* Name of the module */
7253 const sqlite3_module *p, /* Methods for the module */
7254 void *pClientData /* Client data for xCreate/xConnect */
7255);
7256SQLITE_API int sqlite3_create_module_v2(
7257 sqlite3 *db, /* SQLite connection to register module with */
7258 const char *zName, /* Name of the module */
7259 const sqlite3_module *p, /* Methods for the module */
7260 void *pClientData, /* Client data for xCreate/xConnect */
7261 void(*xDestroy)(void*) /* Module destructor function */
7262);
7263
7264/*
7265** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7266** METHOD: sqlite3
7267**
7268** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7269** table modules from database connection D except those named on list L.
7270** The L parameter must be either NULL or a pointer to an array of pointers
7271** to strings where the array is terminated by a single NULL pointer.
7272** ^If the L parameter is NULL, then all virtual table modules are removed.
7273**
7274** See also: [sqlite3_create_module()]
7275*/
7276SQLITE_API int sqlite3_drop_modules(
7277 sqlite3 *db, /* Remove modules from this connection */
7278 const char **azKeep /* Except, do not remove the ones named here */
7279);
7280
7281/*
7282** CAPI3REF: Virtual Table Instance Object
7283** KEYWORDS: sqlite3_vtab
7284**
7285** Every [virtual table module] implementation uses a subclass
7286** of this object to describe a particular instance
7287** of the [virtual table]. Each subclass will
7288** be tailored to the specific needs of the module implementation.
7289** The purpose of this superclass is to define certain fields that are
7290** common to all module implementations.
7291**
7292** ^Virtual tables methods can set an error message by assigning a
7293** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7294** take care that any prior string is freed by a call to [sqlite3_free()]
7295** prior to assigning a new string to zErrMsg. ^After the error message
7296** is delivered up to the client application, the string will be automatically
7297** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7298*/
7299struct sqlite3_vtab {
7300 const sqlite3_module *pModule; /* The module for this virtual table */
7301 int nRef; /* Number of open cursors */
7302 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7303 /* Virtual table implementations will typically add additional fields */
7304};
7305
7306/*
7307** CAPI3REF: Virtual Table Cursor Object
7308** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7309**
7310** Every [virtual table module] implementation uses a subclass of the
7311** following structure to describe cursors that point into the
7312** [virtual table] and are used
7313** to loop through the virtual table. Cursors are created using the
7314** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7315** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7316** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7317** of the module. Each module implementation will define
7318** the content of a cursor structure to suit its own needs.
7319**
7320** This superclass exists in order to define fields of the cursor that
7321** are common to all implementations.
7322*/
7323struct sqlite3_vtab_cursor {
7324 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7325 /* Virtual table implementations will typically add additional fields */
7326};
7327
7328/*
7329** CAPI3REF: Declare The Schema Of A Virtual Table
7330**
7331** ^The [xCreate] and [xConnect] methods of a
7332** [virtual table module] call this interface
7333** to declare the format (the names and datatypes of the columns) of
7334** the virtual tables they implement.
7335*/
7336SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7337
7338/*
7339** CAPI3REF: Overload A Function For A Virtual Table
7340** METHOD: sqlite3
7341**
7342** ^(Virtual tables can provide alternative implementations of functions
7343** using the [xFindFunction] method of the [virtual table module].
7344** But global versions of those functions
7345** must exist in order to be overloaded.)^
7346**
7347** ^(This API makes sure a global version of a function with a particular
7348** name and number of parameters exists. If no such function exists
7349** before this API is called, a new function is created.)^ ^The implementation
7350** of the new function always causes an exception to be thrown. So
7351** the new function is not good for anything by itself. Its only
7352** purpose is to be a placeholder function that can be overloaded
7353** by a [virtual table].
7354*/
7355SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7356
7357/*
7358** The interface to the virtual-table mechanism defined above (back up
7359** to a comment remarkably similar to this one) is currently considered
7360** to be experimental. The interface might change in incompatible ways.
7361** If this is a problem for you, do not use the interface at this time.
7362**
7363** When the virtual-table mechanism stabilizes, we will declare the
7364** interface fixed, support it indefinitely, and remove this comment.
7365*/
7366
7367/*
7368** CAPI3REF: A Handle To An Open BLOB
7369** KEYWORDS: {BLOB handle} {BLOB handles}
7370**
7371** An instance of this object represents an open BLOB on which
7372** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7373** ^Objects of this type are created by [sqlite3_blob_open()]
7374** and destroyed by [sqlite3_blob_close()].
7375** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7376** can be used to read or write small subsections of the BLOB.
7377** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7378*/
7379typedef struct sqlite3_blob sqlite3_blob;
7380
7381/*
7382** CAPI3REF: Open A BLOB For Incremental I/O
7383** METHOD: sqlite3
7384** CONSTRUCTOR: sqlite3_blob
7385**
7386** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7387** in row iRow, column zColumn, table zTable in database zDb;
7388** in other words, the same BLOB that would be selected by:
7389**
7390** <pre>
7391** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7392** </pre>)^
7393**
7394** ^(Parameter zDb is not the filename that contains the database, but
7395** rather the symbolic name of the database. For attached databases, this is
7396** the name that appears after the AS keyword in the [ATTACH] statement.
7397** For the main database file, the database name is "main". For TEMP
7398** tables, the database name is "temp".)^
7399**
7400** ^If the flags parameter is non-zero, then the BLOB is opened for read
7401** and write access. ^If the flags parameter is zero, the BLOB is opened for
7402** read-only access.
7403**
7404** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7405** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7406** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7407** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7408** on *ppBlob after this function it returns.
7409**
7410** This function fails with SQLITE_ERROR if any of the following are true:
7411** <ul>
7412** <li> ^(Database zDb does not exist)^,
7413** <li> ^(Table zTable does not exist within database zDb)^,
7414** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7415** <li> ^(Column zColumn does not exist)^,
7416** <li> ^(Row iRow is not present in the table)^,
7417** <li> ^(The specified column of row iRow contains a value that is not
7418** a TEXT or BLOB value)^,
7419** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7420** constraint and the blob is being opened for read/write access)^,
7421** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7422** column zColumn is part of a [child key] definition and the blob is
7423** being opened for read/write access)^.
7424** </ul>
7425**
7426** ^Unless it returns SQLITE_MISUSE, this function sets the
7427** [database connection] error code and message accessible via
7428** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7429**
7430** A BLOB referenced by sqlite3_blob_open() may be read using the
7431** [sqlite3_blob_read()] interface and modified by using
7432** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7433** different row of the same table using the [sqlite3_blob_reopen()]
7434** interface. However, the column, table, or database of a [BLOB handle]
7435** cannot be changed after the [BLOB handle] is opened.
7436**
7437** ^(If the row that a BLOB handle points to is modified by an
7438** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7439** then the BLOB handle is marked as "expired".
7440** This is true if any column of the row is changed, even a column
7441** other than the one the BLOB handle is open on.)^
7442** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7443** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7444** ^(Changes written into a BLOB prior to the BLOB expiring are not
7445** rolled back by the expiration of the BLOB. Such changes will eventually
7446** commit if the transaction continues to completion.)^
7447**
7448** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7449** the opened blob. ^The size of a blob may not be changed by this
7450** interface. Use the [UPDATE] SQL command to change the size of a
7451** blob.
7452**
7453** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7454** and the built-in [zeroblob] SQL function may be used to create a
7455** zero-filled blob to read or write using the incremental-blob interface.
7456**
7457** To avoid a resource leak, every open [BLOB handle] should eventually
7458** be released by a call to [sqlite3_blob_close()].
7459**
7460** See also: [sqlite3_blob_close()],
7461** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7462** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
7463*/
7464SQLITE_API int sqlite3_blob_open(
7465 sqlite3*,
7466 const char *zDb,
7467 const char *zTable,
7468 const char *zColumn,
7469 sqlite3_int64 iRow,
7470 int flags,
7471 sqlite3_blob **ppBlob
7472);
7473
7474/*
7475** CAPI3REF: Move a BLOB Handle to a New Row
7476** METHOD: sqlite3_blob
7477**
7478** ^This function is used to move an existing [BLOB handle] so that it points
7479** to a different row of the same database table. ^The new row is identified
7480** by the rowid value passed as the second argument. Only the row can be
7481** changed. ^The database, table and column on which the blob handle is open
7482** remain the same. Moving an existing [BLOB handle] to a new row is
7483** faster than closing the existing handle and opening a new one.
7484**
7485** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7486** it must exist and there must be either a blob or text value stored in
7487** the nominated column.)^ ^If the new row is not present in the table, or if
7488** it does not contain a blob or text value, or if another error occurs, an
7489** SQLite error code is returned and the blob handle is considered aborted.
7490** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7491** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7492** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7493** always returns zero.
7494**
7495** ^This function sets the database handle error code and message.
7496*/
7497SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
7498
7499/*
7500** CAPI3REF: Close A BLOB Handle
7501** DESTRUCTOR: sqlite3_blob
7502**
7503** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
7504** unconditionally. Even if this routine returns an error code, the
7505** handle is still closed.)^
7506**
7507** ^If the blob handle being closed was opened for read-write access, and if
7508** the database is in auto-commit mode and there are no other open read-write
7509** blob handles or active write statements, the current transaction is
7510** committed. ^If an error occurs while committing the transaction, an error
7511** code is returned and the transaction rolled back.
7512**
7513** Calling this function with an argument that is not a NULL pointer or an
7514** open blob handle results in undefined behaviour. ^Calling this routine
7515** with a null pointer (such as would be returned by a failed call to
7516** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
7517** is passed a valid open blob handle, the values returned by the
7518** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
7519*/
7520SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7521
7522/*
7523** CAPI3REF: Return The Size Of An Open BLOB
7524** METHOD: sqlite3_blob
7525**
7526** ^Returns the size in bytes of the BLOB accessible via the
7527** successfully opened [BLOB handle] in its only argument. ^The
7528** incremental blob I/O routines can only read or overwriting existing
7529** blob content; they cannot change the size of a blob.
7530**
7531** This routine only works on a [BLOB handle] which has been created
7532** by a prior successful call to [sqlite3_blob_open()] and which has not
7533** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7534** to this routine results in undefined and probably undesirable behavior.
7535*/
7536SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7537
7538/*
7539** CAPI3REF: Read Data From A BLOB Incrementally
7540** METHOD: sqlite3_blob
7541**
7542** ^(This function is used to read data from an open [BLOB handle] into a
7543** caller-supplied buffer. N bytes of data are copied into buffer Z
7544** from the open BLOB, starting at offset iOffset.)^
7545**
7546** ^If offset iOffset is less than N bytes from the end of the BLOB,
7547** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7548** less than zero, [SQLITE_ERROR] is returned and no data is read.
7549** ^The size of the blob (and hence the maximum value of N+iOffset)
7550** can be determined using the [sqlite3_blob_bytes()] interface.
7551**
7552** ^An attempt to read from an expired [BLOB handle] fails with an
7553** error code of [SQLITE_ABORT].
7554**
7555** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7556** Otherwise, an [error code] or an [extended error code] is returned.)^
7557**
7558** This routine only works on a [BLOB handle] which has been created
7559** by a prior successful call to [sqlite3_blob_open()] and which has not
7560** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7561** to this routine results in undefined and probably undesirable behavior.
7562**
7563** See also: [sqlite3_blob_write()].
7564*/
7565SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7566
7567/*
7568** CAPI3REF: Write Data Into A BLOB Incrementally
7569** METHOD: sqlite3_blob
7570**
7571** ^(This function is used to write data into an open [BLOB handle] from a
7572** caller-supplied buffer. N bytes of data are copied from the buffer Z
7573** into the open BLOB, starting at offset iOffset.)^
7574**
7575** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7576** Otherwise, an [error code] or an [extended error code] is returned.)^
7577** ^Unless SQLITE_MISUSE is returned, this function sets the
7578** [database connection] error code and message accessible via
7579** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7580**
7581** ^If the [BLOB handle] passed as the first argument was not opened for
7582** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7583** this function returns [SQLITE_READONLY].
7584**
7585** This function may only modify the contents of the BLOB; it is
7586** not possible to increase the size of a BLOB using this API.
7587** ^If offset iOffset is less than N bytes from the end of the BLOB,
7588** [SQLITE_ERROR] is returned and no data is written. The size of the
7589** BLOB (and hence the maximum value of N+iOffset) can be determined
7590** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
7591** than zero [SQLITE_ERROR] is returned and no data is written.
7592**
7593** ^An attempt to write to an expired [BLOB handle] fails with an
7594** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7595** before the [BLOB handle] expired are not rolled back by the
7596** expiration of the handle, though of course those changes might
7597** have been overwritten by the statement that expired the BLOB handle
7598** or by other independent statements.
7599**
7600** This routine only works on a [BLOB handle] which has been created
7601** by a prior successful call to [sqlite3_blob_open()] and which has not
7602** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7603** to this routine results in undefined and probably undesirable behavior.
7604**
7605** See also: [sqlite3_blob_read()].
7606*/
7607SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7608
7609/*
7610** CAPI3REF: Virtual File System Objects
7611**
7612** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7613** that SQLite uses to interact
7614** with the underlying operating system. Most SQLite builds come with a
7615** single default VFS that is appropriate for the host computer.
7616** New VFSes can be registered and existing VFSes can be unregistered.
7617** The following interfaces are provided.
7618**
7619** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7620** ^Names are case sensitive.
7621** ^Names are zero-terminated UTF-8 strings.
7622** ^If there is no match, a NULL pointer is returned.
7623** ^If zVfsName is NULL then the default VFS is returned.
7624**
7625** ^New VFSes are registered with sqlite3_vfs_register().
7626** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7627** ^The same VFS can be registered multiple times without injury.
7628** ^To make an existing VFS into the default VFS, register it again
7629** with the makeDflt flag set. If two different VFSes with the
7630** same name are registered, the behavior is undefined. If a
7631** VFS is registered with a name that is NULL or an empty string,
7632** then the behavior is undefined.
7633**
7634** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7635** ^(If the default VFS is unregistered, another VFS is chosen as
7636** the default. The choice for the new VFS is arbitrary.)^
7637*/
7638SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7639SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7640SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7641
7642/*
7643** CAPI3REF: Mutexes
7644**
7645** The SQLite core uses these routines for thread
7646** synchronization. Though they are intended for internal
7647** use by SQLite, code that links against SQLite is
7648** permitted to use any of these routines.
7649**
7650** The SQLite source code contains multiple implementations
7651** of these mutex routines. An appropriate implementation
7652** is selected automatically at compile-time. The following
7653** implementations are available in the SQLite core:
7654**
7655** <ul>
7656** <li> SQLITE_MUTEX_PTHREADS
7657** <li> SQLITE_MUTEX_W32
7658** <li> SQLITE_MUTEX_NOOP
7659** </ul>
7660**
7661** The SQLITE_MUTEX_NOOP implementation is a set of routines
7662** that does no real locking and is appropriate for use in
7663** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
7664** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7665** and Windows.
7666**
7667** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
7668** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7669** implementation is included with the library. In this case the
7670** application must supply a custom mutex implementation using the
7671** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7672** before calling sqlite3_initialize() or any other public sqlite3_
7673** function that calls sqlite3_initialize().
7674**
7675** ^The sqlite3_mutex_alloc() routine allocates a new
7676** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
7677** routine returns NULL if it is unable to allocate the requested
7678** mutex. The argument to sqlite3_mutex_alloc() must one of these
7679** integer constants:
7680**
7681** <ul>
7682** <li> SQLITE_MUTEX_FAST
7683** <li> SQLITE_MUTEX_RECURSIVE
7684** <li> SQLITE_MUTEX_STATIC_MAIN
7685** <li> SQLITE_MUTEX_STATIC_MEM
7686** <li> SQLITE_MUTEX_STATIC_OPEN
7687** <li> SQLITE_MUTEX_STATIC_PRNG
7688** <li> SQLITE_MUTEX_STATIC_LRU
7689** <li> SQLITE_MUTEX_STATIC_PMEM
7690** <li> SQLITE_MUTEX_STATIC_APP1
7691** <li> SQLITE_MUTEX_STATIC_APP2
7692** <li> SQLITE_MUTEX_STATIC_APP3
7693** <li> SQLITE_MUTEX_STATIC_VFS1
7694** <li> SQLITE_MUTEX_STATIC_VFS2
7695** <li> SQLITE_MUTEX_STATIC_VFS3
7696** </ul>
7697**
7698** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
7699** cause sqlite3_mutex_alloc() to create
7700** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
7701** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
7702** The mutex implementation does not need to make a distinction
7703** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
7704** not want to. SQLite will only request a recursive mutex in
7705** cases where it really needs one. If a faster non-recursive mutex
7706** implementation is available on the host platform, the mutex subsystem
7707** might return such a mutex in response to SQLITE_MUTEX_FAST.
7708**
7709** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
7710** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
7711** a pointer to a static preexisting mutex. ^Nine static mutexes are
7712** used by the current version of SQLite. Future versions of SQLite
7713** may add additional static mutexes. Static mutexes are for internal
7714** use by SQLite only. Applications that use SQLite mutexes should
7715** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
7716** SQLITE_MUTEX_RECURSIVE.
7717**
7718** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
7719** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
7720** returns a different mutex on every call. ^For the static
7721** mutex types, the same mutex is returned on every call that has
7722** the same type number.
7723**
7724** ^The sqlite3_mutex_free() routine deallocates a previously
7725** allocated dynamic mutex. Attempting to deallocate a static
7726** mutex results in undefined behavior.
7727**
7728** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
7729** to enter a mutex. ^If another thread is already within the mutex,
7730** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
7731** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
7732** upon successful entry. ^(Mutexes created using
7733** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
7734** In such cases, the
7735** mutex must be exited an equal number of times before another thread
7736** can enter.)^ If the same thread tries to enter any mutex other
7737** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
7738**
7739** ^(Some systems (for example, Windows 95) do not support the operation
7740** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
7741** will always return SQLITE_BUSY. The SQLite core only ever uses
7742** sqlite3_mutex_try() as an optimization so this is acceptable
7743** behavior.)^
7744**
7745** ^The sqlite3_mutex_leave() routine exits a mutex that was
7746** previously entered by the same thread. The behavior
7747** is undefined if the mutex is not currently entered by the
7748** calling thread or is not currently allocated.
7749**
7750** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
7751** sqlite3_mutex_leave() is a NULL pointer, then all three routines
7752** behave as no-ops.
7753**
7754** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
7755*/
7756SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
7757SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
7758SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
7759SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
7760SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
7761
7762/*
7763** CAPI3REF: Mutex Methods Object
7764**
7765** An instance of this structure defines the low-level routines
7766** used to allocate and use mutexes.
7767**
7768** Usually, the default mutex implementations provided by SQLite are
7769** sufficient, however the application has the option of substituting a custom
7770** implementation for specialized deployments or systems for which SQLite
7771** does not provide a suitable implementation. In this case, the application
7772** creates and populates an instance of this structure to pass
7773** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
7774** Additionally, an instance of this structure can be used as an
7775** output variable when querying the system for the current mutex
7776** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
7777**
7778** ^The xMutexInit method defined by this structure is invoked as
7779** part of system initialization by the sqlite3_initialize() function.
7780** ^The xMutexInit routine is called by SQLite exactly once for each
7781** effective call to [sqlite3_initialize()].
7782**
7783** ^The xMutexEnd method defined by this structure is invoked as
7784** part of system shutdown by the sqlite3_shutdown() function. The
7785** implementation of this method is expected to release all outstanding
7786** resources obtained by the mutex methods implementation, especially
7787** those obtained by the xMutexInit method. ^The xMutexEnd()
7788** interface is invoked exactly once for each call to [sqlite3_shutdown()].
7789**
7790** ^(The remaining seven methods defined by this structure (xMutexAlloc,
7791** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
7792** xMutexNotheld) implement the following interfaces (respectively):
7793**
7794** <ul>
7795** <li> [sqlite3_mutex_alloc()] </li>
7796** <li> [sqlite3_mutex_free()] </li>
7797** <li> [sqlite3_mutex_enter()] </li>
7798** <li> [sqlite3_mutex_try()] </li>
7799** <li> [sqlite3_mutex_leave()] </li>
7800** <li> [sqlite3_mutex_held()] </li>
7801** <li> [sqlite3_mutex_notheld()] </li>
7802** </ul>)^
7803**
7804** The only difference is that the public sqlite3_XXX functions enumerated
7805** above silently ignore any invocations that pass a NULL pointer instead
7806** of a valid mutex handle. The implementations of the methods defined
7807** by this structure are not required to handle this case. The results
7808** of passing a NULL pointer instead of a valid mutex handle are undefined
7809** (i.e. it is acceptable to provide an implementation that segfaults if
7810** it is passed a NULL pointer).
7811**
7812** The xMutexInit() method must be threadsafe. It must be harmless to
7813** invoke xMutexInit() multiple times within the same process and without
7814** intervening calls to xMutexEnd(). Second and subsequent calls to
7815** xMutexInit() must be no-ops.
7816**
7817** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
7818** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
7819** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
7820** memory allocation for a fast or recursive mutex.
7821**
7822** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
7823** called, but only if the prior call to xMutexInit returned SQLITE_OK.
7824** If xMutexInit fails in any way, it is expected to clean up after itself
7825** prior to returning.
7826*/
7827typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
7828struct sqlite3_mutex_methods {
7829 int (*xMutexInit)(void);
7830 int (*xMutexEnd)(void);
7831 sqlite3_mutex *(*xMutexAlloc)(int);
7832 void (*xMutexFree)(sqlite3_mutex *);
7833 void (*xMutexEnter)(sqlite3_mutex *);
7834 int (*xMutexTry)(sqlite3_mutex *);
7835 void (*xMutexLeave)(sqlite3_mutex *);
7836 int (*xMutexHeld)(sqlite3_mutex *);
7837 int (*xMutexNotheld)(sqlite3_mutex *);
7838};
7839
7840/*
7841** CAPI3REF: Mutex Verification Routines
7842**
7843** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
7844** are intended for use inside assert() statements. The SQLite core
7845** never uses these routines except inside an assert() and applications
7846** are advised to follow the lead of the core. The SQLite core only
7847** provides implementations for these routines when it is compiled
7848** with the SQLITE_DEBUG flag. External mutex implementations
7849** are only required to provide these routines if SQLITE_DEBUG is
7850** defined and if NDEBUG is not defined.
7851**
7852** These routines should return true if the mutex in their argument
7853** is held or not held, respectively, by the calling thread.
7854**
7855** The implementation is not required to provide versions of these
7856** routines that actually work. If the implementation does not provide working
7857** versions of these routines, it should at least provide stubs that always
7858** return true so that one does not get spurious assertion failures.
7859**
7860** If the argument to sqlite3_mutex_held() is a NULL pointer then
7861** the routine should return 1. This seems counter-intuitive since
7862** clearly the mutex cannot be held if it does not exist. But
7863** the reason the mutex does not exist is because the build is not
7864** using mutexes. And we do not want the assert() containing the
7865** call to sqlite3_mutex_held() to fail, so a non-zero return is
7866** the appropriate thing to do. The sqlite3_mutex_notheld()
7867** interface should also return 1 when given a NULL pointer.
7868*/
7869#ifndef NDEBUG
7870SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
7871SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
7872#endif
7873
7874/*
7875** CAPI3REF: Mutex Types
7876**
7877** The [sqlite3_mutex_alloc()] interface takes a single argument
7878** which is one of these integer constants.
7879**
7880** The set of static mutexes may change from one SQLite release to the
7881** next. Applications that override the built-in mutex logic must be
7882** prepared to accommodate additional static mutexes.
7883*/
7884#define SQLITE_MUTEX_FAST 0
7885#define SQLITE_MUTEX_RECURSIVE 1
7886#define SQLITE_MUTEX_STATIC_MAIN 2
7887#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
7888#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
7889#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
7890#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
7891#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
7892#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
7893#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
7894#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
7895#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
7896#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
7897#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
7898#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
7899#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
7900
7901/* Legacy compatibility: */
7902#define SQLITE_MUTEX_STATIC_MASTER 2
7903
7904
7905/*
7906** CAPI3REF: Retrieve the mutex for a database connection
7907** METHOD: sqlite3
7908**
7909** ^This interface returns a pointer the [sqlite3_mutex] object that
7910** serializes access to the [database connection] given in the argument
7911** when the [threading mode] is Serialized.
7912** ^If the [threading mode] is Single-thread or Multi-thread then this
7913** routine returns a NULL pointer.
7914*/
7915SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
7916
7917/*
7918** CAPI3REF: Low-Level Control Of Database Files
7919** METHOD: sqlite3
7920** KEYWORDS: {file control}
7921**
7922** ^The [sqlite3_file_control()] interface makes a direct call to the
7923** xFileControl method for the [sqlite3_io_methods] object associated
7924** with a particular database identified by the second argument. ^The
7925** name of the database is "main" for the main database or "temp" for the
7926** TEMP database, or the name that appears after the AS keyword for
7927** databases that are added using the [ATTACH] SQL command.
7928** ^A NULL pointer can be used in place of "main" to refer to the
7929** main database file.
7930** ^The third and fourth parameters to this routine
7931** are passed directly through to the second and third parameters of
7932** the xFileControl method. ^The return value of the xFileControl
7933** method becomes the return value of this routine.
7934**
7935** A few opcodes for [sqlite3_file_control()] are handled directly
7936** by the SQLite core and never invoke the
7937** sqlite3_io_methods.xFileControl method.
7938** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
7939** a pointer to the underlying [sqlite3_file] object to be written into
7940** the space pointed to by the 4th parameter. The
7941** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
7942** the [sqlite3_file] object associated with the journal file instead of
7943** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
7944** a pointer to the underlying [sqlite3_vfs] object for the file.
7945** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
7946** from the pager.
7947**
7948** ^If the second parameter (zDbName) does not match the name of any
7949** open database file, then SQLITE_ERROR is returned. ^This error
7950** code is not remembered and will not be recalled by [sqlite3_errcode()]
7951** or [sqlite3_errmsg()]. The underlying xFileControl method might
7952** also return SQLITE_ERROR. There is no way to distinguish between
7953** an incorrect zDbName and an SQLITE_ERROR return from the underlying
7954** xFileControl method.
7955**
7956** See also: [file control opcodes]
7957*/
7958SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
7959
7960/*
7961** CAPI3REF: Testing Interface
7962**
7963** ^The sqlite3_test_control() interface is used to read out internal
7964** state of SQLite and to inject faults into SQLite for testing
7965** purposes. ^The first parameter is an operation code that determines
7966** the number, meaning, and operation of all subsequent parameters.
7967**
7968** This interface is not for use by applications. It exists solely
7969** for verifying the correct operation of the SQLite library. Depending
7970** on how the SQLite library is compiled, this interface might not exist.
7971**
7972** The details of the operation codes, their meanings, the parameters
7973** they take, and what they do are all subject to change without notice.
7974** Unlike most of the SQLite API, this function is not guaranteed to
7975** operate consistently from one release to the next.
7976*/
7977SQLITE_API int sqlite3_test_control(int op, ...);
7978
7979/*
7980** CAPI3REF: Testing Interface Operation Codes
7981**
7982** These constants are the valid operation code parameters used
7983** as the first argument to [sqlite3_test_control()].
7984**
7985** These parameters and their meanings are subject to change
7986** without notice. These values are for testing purposes only.
7987** Applications should not use any of these parameters or the
7988** [sqlite3_test_control()] interface.
7989*/
7990#define SQLITE_TESTCTRL_FIRST 5
7991#define SQLITE_TESTCTRL_PRNG_SAVE 5
7992#define SQLITE_TESTCTRL_PRNG_RESTORE 6
7993#define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
7994#define SQLITE_TESTCTRL_BITVEC_TEST 8
7995#define SQLITE_TESTCTRL_FAULT_INSTALL 9
7996#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
7997#define SQLITE_TESTCTRL_PENDING_BYTE 11
7998#define SQLITE_TESTCTRL_ASSERT 12
7999#define SQLITE_TESTCTRL_ALWAYS 13
8000#define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8001#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8002#define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8003#define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8004#define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8005#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8006#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8007#define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8008#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8009#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8010#define SQLITE_TESTCTRL_BYTEORDER 22
8011#define SQLITE_TESTCTRL_ISINIT 23
8012#define SQLITE_TESTCTRL_SORTER_MMAP 24
8013#define SQLITE_TESTCTRL_IMPOSTER 25
8014#define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8015#define SQLITE_TESTCTRL_RESULT_INTREAL 27
8016#define SQLITE_TESTCTRL_PRNG_SEED 28
8017#define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8018#define SQLITE_TESTCTRL_SEEK_COUNT 30
8019#define SQLITE_TESTCTRL_TRACEFLAGS 31
8020#define SQLITE_TESTCTRL_TUNE 32
8021#define SQLITE_TESTCTRL_LOGEST 33
8022#define SQLITE_TESTCTRL_LAST 33 /* Largest TESTCTRL */
8023
8024/*
8025** CAPI3REF: SQL Keyword Checking
8026**
8027** These routines provide access to the set of SQL language keywords
8028** recognized by SQLite. Applications can uses these routines to determine
8029** whether or not a specific identifier needs to be escaped (for example,
8030** by enclosing in double-quotes) so as not to confuse the parser.
8031**
8032** The sqlite3_keyword_count() interface returns the number of distinct
8033** keywords understood by SQLite.
8034**
8035** The sqlite3_keyword_name(N,Z,L) interface finds the N-th keyword and
8036** makes *Z point to that keyword expressed as UTF8 and writes the number
8037** of bytes in the keyword into *L. The string that *Z points to is not
8038** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8039** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8040** or L are NULL or invalid pointers then calls to
8041** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8042**
8043** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8044** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8045** if it is and zero if not.
8046**
8047** The parser used by SQLite is forgiving. It is often possible to use
8048** a keyword as an identifier as long as such use does not result in a
8049** parsing ambiguity. For example, the statement
8050** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8051** creates a new table named "BEGIN" with three columns named
8052** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8053** using keywords as identifiers. Common techniques used to avoid keyword
8054** name collisions include:
8055** <ul>
8056** <li> Put all identifier names inside double-quotes. This is the official
8057** SQL way to escape identifier names.
8058** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
8059** but it is what SQL Server does and so lots of programmers use this
8060** technique.
8061** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8062** with "Z".
8063** <li> Include a digit somewhere in every identifier name.
8064** </ul>
8065**
8066** Note that the number of keywords understood by SQLite can depend on
8067** compile-time options. For example, "VACUUM" is not a keyword if
8068** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8069** new keywords may be added to future releases of SQLite.
8070*/
8071SQLITE_API int sqlite3_keyword_count(void);
8072SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8073SQLITE_API int sqlite3_keyword_check(const char*,int);
8074
8075/*
8076** CAPI3REF: Dynamic String Object
8077** KEYWORDS: {dynamic string}
8078**
8079** An instance of the sqlite3_str object contains a dynamically-sized
8080** string under construction.
8081**
8082** The lifecycle of an sqlite3_str object is as follows:
8083** <ol>
8084** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8085** <li> ^Text is appended to the sqlite3_str object using various
8086** methods, such as [sqlite3_str_appendf()].
8087** <li> ^The sqlite3_str object is destroyed and the string it created
8088** is returned using the [sqlite3_str_finish()] interface.
8089** </ol>
8090*/
8091typedef struct sqlite3_str sqlite3_str;
8092
8093/*
8094** CAPI3REF: Create A New Dynamic String Object
8095** CONSTRUCTOR: sqlite3_str
8096**
8097** ^The [sqlite3_str_new(D)] interface allocates and initializes
8098** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8099** [sqlite3_str_new()] must be freed by a subsequent call to
8100** [sqlite3_str_finish(X)].
8101**
8102** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8103** valid [sqlite3_str] object, though in the event of an out-of-memory
8104** error the returned object might be a special singleton that will
8105** silently reject new text, always return SQLITE_NOMEM from
8106** [sqlite3_str_errcode()], always return 0 for
8107** [sqlite3_str_length()], and always return NULL from
8108** [sqlite3_str_finish(X)]. It is always safe to use the value
8109** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8110** to any of the other [sqlite3_str] methods.
8111**
8112** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8113** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8114** length of the string contained in the [sqlite3_str] object will be
8115** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8116** of [SQLITE_MAX_LENGTH].
8117*/
8118SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8119
8120/*
8121** CAPI3REF: Finalize A Dynamic String
8122** DESTRUCTOR: sqlite3_str
8123**
8124** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8125** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8126** that contains the constructed string. The calling application should
8127** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8128** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8129** errors were encountered during construction of the string. ^The
8130** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8131** string in [sqlite3_str] object X is zero bytes long.
8132*/
8133SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8134
8135/*
8136** CAPI3REF: Add Content To A Dynamic String
8137** METHOD: sqlite3_str
8138**
8139** These interfaces add content to an sqlite3_str object previously obtained
8140** from [sqlite3_str_new()].
8141**
8142** ^The [sqlite3_str_appendf(X,F,...)] and
8143** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8144** functionality of SQLite to append formatted text onto the end of
8145** [sqlite3_str] object X.
8146**
8147** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8148** onto the end of the [sqlite3_str] object X. N must be non-negative.
8149** S must contain at least N non-zero bytes of content. To append a
8150** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8151** method instead.
8152**
8153** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8154** zero-terminated string S onto the end of [sqlite3_str] object X.
8155**
8156** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8157** single-byte character C onto the end of [sqlite3_str] object X.
8158** ^This method can be used, for example, to add whitespace indentation.
8159**
8160** ^The [sqlite3_str_reset(X)] method resets the string under construction
8161** inside [sqlite3_str] object X back to zero bytes in length.
8162**
8163** These methods do not return a result code. ^If an error occurs, that fact
8164** is recorded in the [sqlite3_str] object and can be recovered by a
8165** subsequent call to [sqlite3_str_errcode(X)].
8166*/
8167SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8168SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8169SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8170SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8171SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8172SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8173
8174/*
8175** CAPI3REF: Status Of A Dynamic String
8176** METHOD: sqlite3_str
8177**
8178** These interfaces return the current status of an [sqlite3_str] object.
8179**
8180** ^If any prior errors have occurred while constructing the dynamic string
8181** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8182** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8183** [SQLITE_NOMEM] following any out-of-memory error, or
8184** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8185** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8186**
8187** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8188** of the dynamic string under construction in [sqlite3_str] object X.
8189** ^The length returned by [sqlite3_str_length(X)] does not include the
8190** zero-termination byte.
8191**
8192** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8193** content of the dynamic string under construction in X. The value
8194** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8195** and might be freed or altered by any subsequent method on the same
8196** [sqlite3_str] object. Applications must not used the pointer returned
8197** [sqlite3_str_value(X)] after any subsequent method call on the same
8198** object. ^Applications may change the content of the string returned
8199** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8200** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8201** write any byte after any subsequent sqlite3_str method call.
8202*/
8203SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8204SQLITE_API int sqlite3_str_length(sqlite3_str*);
8205SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8206
8207/*
8208** CAPI3REF: SQLite Runtime Status
8209**
8210** ^These interfaces are used to retrieve runtime status information
8211** about the performance of SQLite, and optionally to reset various
8212** highwater marks. ^The first argument is an integer code for
8213** the specific parameter to measure. ^(Recognized integer codes
8214** are of the form [status parameters | SQLITE_STATUS_...].)^
8215** ^The current value of the parameter is returned into *pCurrent.
8216** ^The highest recorded value is returned in *pHighwater. ^If the
8217** resetFlag is true, then the highest record value is reset after
8218** *pHighwater is written. ^(Some parameters do not record the highest
8219** value. For those parameters
8220** nothing is written into *pHighwater and the resetFlag is ignored.)^
8221** ^(Other parameters record only the highwater mark and not the current
8222** value. For these latter parameters nothing is written into *pCurrent.)^
8223**
8224** ^The sqlite3_status() and sqlite3_status64() routines return
8225** SQLITE_OK on success and a non-zero [error code] on failure.
8226**
8227** If either the current value or the highwater mark is too large to
8228** be represented by a 32-bit integer, then the values returned by
8229** sqlite3_status() are undefined.
8230**
8231** See also: [sqlite3_db_status()]
8232*/
8233SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8234SQLITE_API int sqlite3_status64(
8235 int op,
8236 sqlite3_int64 *pCurrent,
8237 sqlite3_int64 *pHighwater,
8238 int resetFlag
8239);
8240
8241
8242/*
8243** CAPI3REF: Status Parameters
8244** KEYWORDS: {status parameters}
8245**
8246** These integer constants designate various run-time status parameters
8247** that can be returned by [sqlite3_status()].
8248**
8249** <dl>
8250** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8251** <dd>This parameter is the current amount of memory checked out
8252** using [sqlite3_malloc()], either directly or indirectly. The
8253** figure includes calls made to [sqlite3_malloc()] by the application
8254** and internal memory usage by the SQLite library. Auxiliary page-cache
8255** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8256** this parameter. The amount returned is the sum of the allocation
8257** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8258**
8259** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8260** <dd>This parameter records the largest memory allocation request
8261** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8262** internal equivalents). Only the value returned in the
8263** *pHighwater parameter to [sqlite3_status()] is of interest.
8264** The value written into the *pCurrent parameter is undefined.</dd>)^
8265**
8266** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8267** <dd>This parameter records the number of separate memory allocations
8268** currently checked out.</dd>)^
8269**
8270** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8271** <dd>This parameter returns the number of pages used out of the
8272** [pagecache memory allocator] that was configured using
8273** [SQLITE_CONFIG_PAGECACHE]. The
8274** value returned is in pages, not in bytes.</dd>)^
8275**
8276** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8277** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8278** <dd>This parameter returns the number of bytes of page cache
8279** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8280** buffer and where forced to overflow to [sqlite3_malloc()]. The
8281** returned value includes allocations that overflowed because they
8282** where too large (they were larger than the "sz" parameter to
8283** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8284** no space was left in the page cache.</dd>)^
8285**
8286** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8287** <dd>This parameter records the largest memory allocation request
8288** handed to the [pagecache memory allocator]. Only the value returned in the
8289** *pHighwater parameter to [sqlite3_status()] is of interest.
8290** The value written into the *pCurrent parameter is undefined.</dd>)^
8291**
8292** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8293** <dd>No longer used.</dd>
8294**
8295** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8296** <dd>No longer used.</dd>
8297**
8298** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8299** <dd>No longer used.</dd>
8300**
8301** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8302** <dd>The *pHighwater parameter records the deepest parser stack.
8303** The *pCurrent value is undefined. The *pHighwater value is only
8304** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8305** </dl>
8306**
8307** New status parameters may be added from time to time.
8308*/
8309#define SQLITE_STATUS_MEMORY_USED 0
8310#define SQLITE_STATUS_PAGECACHE_USED 1
8311#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8312#define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8313#define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8314#define SQLITE_STATUS_MALLOC_SIZE 5
8315#define SQLITE_STATUS_PARSER_STACK 6
8316#define SQLITE_STATUS_PAGECACHE_SIZE 7
8317#define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8318#define SQLITE_STATUS_MALLOC_COUNT 9
8319
8320/*
8321** CAPI3REF: Database Connection Status
8322** METHOD: sqlite3
8323**
8324** ^This interface is used to retrieve runtime status information
8325** about a single [database connection]. ^The first argument is the
8326** database connection object to be interrogated. ^The second argument
8327** is an integer constant, taken from the set of
8328** [SQLITE_DBSTATUS options], that
8329** determines the parameter to interrogate. The set of
8330** [SQLITE_DBSTATUS options] is likely
8331** to grow in future releases of SQLite.
8332**
8333** ^The current value of the requested parameter is written into *pCur
8334** and the highest instantaneous value is written into *pHiwtr. ^If
8335** the resetFlg is true, then the highest instantaneous value is
8336** reset back down to the current value.
8337**
8338** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8339** non-zero [error code] on failure.
8340**
8341** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8342*/
8343SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8344
8345/*
8346** CAPI3REF: Status Parameters for database connections
8347** KEYWORDS: {SQLITE_DBSTATUS options}
8348**
8349** These constants are the available integer "verbs" that can be passed as
8350** the second argument to the [sqlite3_db_status()] interface.
8351**
8352** New verbs may be added in future releases of SQLite. Existing verbs
8353** might be discontinued. Applications should check the return code from
8354** [sqlite3_db_status()] to make sure that the call worked.
8355** The [sqlite3_db_status()] interface will return a non-zero error code
8356** if a discontinued or unsupported verb is invoked.
8357**
8358** <dl>
8359** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8360** <dd>This parameter returns the number of lookaside memory slots currently
8361** checked out.</dd>)^
8362**
8363** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8364** <dd>This parameter returns the number of malloc attempts that were
8365** satisfied using lookaside memory. Only the high-water value is meaningful;
8366** the current value is always zero.)^
8367**
8368** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8369** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8370** <dd>This parameter returns the number malloc attempts that might have
8371** been satisfied using lookaside memory but failed due to the amount of
8372** memory requested being larger than the lookaside slot size.
8373** Only the high-water value is meaningful;
8374** the current value is always zero.)^
8375**
8376** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8377** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8378** <dd>This parameter returns the number malloc attempts that might have
8379** been satisfied using lookaside memory but failed due to all lookaside
8380** memory already being in use.
8381** Only the high-water value is meaningful;
8382** the current value is always zero.)^
8383**
8384** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8385** <dd>This parameter returns the approximate number of bytes of heap
8386** memory used by all pager caches associated with the database connection.)^
8387** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8388**
8389** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8390** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8391** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8392** pager cache is shared between two or more connections the bytes of heap
8393** memory used by that pager cache is divided evenly between the attached
8394** connections.)^ In other words, if none of the pager caches associated
8395** with the database connection are shared, this request returns the same
8396** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8397** shared, the value returned by this call will be smaller than that returned
8398** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8399** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8400**
8401** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8402** <dd>This parameter returns the approximate number of bytes of heap
8403** memory used to store the schema for all databases associated
8404** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8405** ^The full amount of memory used by the schemas is reported, even if the
8406** schema memory is shared with other database connections due to
8407** [shared cache mode] being enabled.
8408** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8409**
8410** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8411** <dd>This parameter returns the approximate number of bytes of heap
8412** and lookaside memory used by all prepared statements associated with
8413** the database connection.)^
8414** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8415** </dd>
8416**
8417** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8418** <dd>This parameter returns the number of pager cache hits that have
8419** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8420** is always 0.
8421** </dd>
8422**
8423** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8424** <dd>This parameter returns the number of pager cache misses that have
8425** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8426** is always 0.
8427** </dd>
8428**
8429** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8430** <dd>This parameter returns the number of dirty cache entries that have
8431** been written to disk. Specifically, the number of pages written to the
8432** wal file in wal mode databases, or the number of pages written to the
8433** database file in rollback mode databases. Any pages written as part of
8434** transaction rollback or database recovery operations are not included.
8435** If an IO or other error occurs while writing a page to disk, the effect
8436** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8437** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8438** </dd>
8439**
8440** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8441** <dd>This parameter returns the number of dirty cache entries that have
8442** been written to disk in the middle of a transaction due to the page
8443** cache overflowing. Transactions are more efficient if they are written
8444** to disk all at once. When pages spill mid-transaction, that introduces
8445** additional overhead. This parameter can be used help identify
8446** inefficiencies that can be resolved by increasing the cache size.
8447** </dd>
8448**
8449** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8450** <dd>This parameter returns zero for the current value if and only if
8451** all foreign key constraints (deferred or immediate) have been
8452** resolved.)^ ^The highwater mark is always 0.
8453** </dd>
8454** </dl>
8455*/
8456#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8457#define SQLITE_DBSTATUS_CACHE_USED 1
8458#define SQLITE_DBSTATUS_SCHEMA_USED 2
8459#define SQLITE_DBSTATUS_STMT_USED 3
8460#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8461#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8462#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8463#define SQLITE_DBSTATUS_CACHE_HIT 7
8464#define SQLITE_DBSTATUS_CACHE_MISS 8
8465#define SQLITE_DBSTATUS_CACHE_WRITE 9
8466#define SQLITE_DBSTATUS_DEFERRED_FKS 10
8467#define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
8468#define SQLITE_DBSTATUS_CACHE_SPILL 12
8469#define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
8470
8471
8472/*
8473** CAPI3REF: Prepared Statement Status
8474** METHOD: sqlite3_stmt
8475**
8476** ^(Each prepared statement maintains various
8477** [SQLITE_STMTSTATUS counters] that measure the number
8478** of times it has performed specific operations.)^ These counters can
8479** be used to monitor the performance characteristics of the prepared
8480** statements. For example, if the number of table steps greatly exceeds
8481** the number of table searches or result rows, that would tend to indicate
8482** that the prepared statement is using a full table scan rather than
8483** an index.
8484**
8485** ^(This interface is used to retrieve and reset counter values from
8486** a [prepared statement]. The first argument is the prepared statement
8487** object to be interrogated. The second argument
8488** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8489** to be interrogated.)^
8490** ^The current value of the requested counter is returned.
8491** ^If the resetFlg is true, then the counter is reset to zero after this
8492** interface call returns.
8493**
8494** See also: [sqlite3_status()] and [sqlite3_db_status()].
8495*/
8496SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8497
8498/*
8499** CAPI3REF: Status Parameters for prepared statements
8500** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8501**
8502** These preprocessor macros define integer codes that name counter
8503** values associated with the [sqlite3_stmt_status()] interface.
8504** The meanings of the various counters are as follows:
8505**
8506** <dl>
8507** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8508** <dd>^This is the number of times that SQLite has stepped forward in
8509** a table as part of a full table scan. Large numbers for this counter
8510** may indicate opportunities for performance improvement through
8511** careful use of indices.</dd>
8512**
8513** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8514** <dd>^This is the number of sort operations that have occurred.
8515** A non-zero value in this counter may indicate an opportunity to
8516** improvement performance through careful use of indices.</dd>
8517**
8518** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8519** <dd>^This is the number of rows inserted into transient indices that
8520** were created automatically in order to help joins run faster.
8521** A non-zero value in this counter may indicate an opportunity to
8522** improvement performance by adding permanent indices that do not
8523** need to be reinitialized each time the statement is run.</dd>
8524**
8525** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8526** <dd>^This is the number of virtual machine operations executed
8527** by the prepared statement if that number is less than or equal
8528** to 2147483647. The number of virtual machine operations can be
8529** used as a proxy for the total work done by the prepared statement.
8530** If the number of virtual machine operations exceeds 2147483647
8531** then the value returned by this statement status code is undefined.
8532**
8533** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8534** <dd>^This is the number of times that the prepare statement has been
8535** automatically regenerated due to schema changes or changes to
8536** [bound parameters] that might affect the query plan.
8537**
8538** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8539** <dd>^This is the number of times that the prepared statement has
8540** been run. A single "run" for the purposes of this counter is one
8541** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8542** The counter is incremented on the first [sqlite3_step()] call of each
8543** cycle.
8544**
8545** [[SQLITE_STMTSTATUS_FILTER_MISS]]
8546** [[SQLITE_STMTSTATUS_FILTER HIT]]
8547** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
8548** SQLITE_STMTSTATUS_FILTER_MISS</dt>
8549** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
8550** step was bypassed because a Bloom filter returned not-found. The
8551** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
8552** times that the Bloom filter returned a find, and thus the join step
8553** had to be processed as normal.
8554**
8555** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8556** <dd>^This is the approximate number of bytes of heap memory
8557** used to store the prepared statement. ^This value is not actually
8558** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8559** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
8560** </dd>
8561** </dl>
8562*/
8563#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8564#define SQLITE_STMTSTATUS_SORT 2
8565#define SQLITE_STMTSTATUS_AUTOINDEX 3
8566#define SQLITE_STMTSTATUS_VM_STEP 4
8567#define SQLITE_STMTSTATUS_REPREPARE 5
8568#define SQLITE_STMTSTATUS_RUN 6
8569#define SQLITE_STMTSTATUS_FILTER_MISS 7
8570#define SQLITE_STMTSTATUS_FILTER_HIT 8
8571#define SQLITE_STMTSTATUS_MEMUSED 99
8572
8573/*
8574** CAPI3REF: Custom Page Cache Object
8575**
8576** The sqlite3_pcache type is opaque. It is implemented by
8577** the pluggable module. The SQLite core has no knowledge of
8578** its size or internal structure and never deals with the
8579** sqlite3_pcache object except by holding and passing pointers
8580** to the object.
8581**
8582** See [sqlite3_pcache_methods2] for additional information.
8583*/
8584typedef struct sqlite3_pcache sqlite3_pcache;
8585
8586/*
8587** CAPI3REF: Custom Page Cache Object
8588**
8589** The sqlite3_pcache_page object represents a single page in the
8590** page cache. The page cache will allocate instances of this
8591** object. Various methods of the page cache use pointers to instances
8592** of this object as parameters or as their return value.
8593**
8594** See [sqlite3_pcache_methods2] for additional information.
8595*/
8596typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8597struct sqlite3_pcache_page {
8598 void *pBuf; /* The content of the page */
8599 void *pExtra; /* Extra information associated with the page */
8600};
8601
8602/*
8603** CAPI3REF: Application Defined Page Cache.
8604** KEYWORDS: {page cache}
8605**
8606** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
8607** register an alternative page cache implementation by passing in an
8608** instance of the sqlite3_pcache_methods2 structure.)^
8609** In many applications, most of the heap memory allocated by
8610** SQLite is used for the page cache.
8611** By implementing a
8612** custom page cache using this API, an application can better control
8613** the amount of memory consumed by SQLite, the way in which
8614** that memory is allocated and released, and the policies used to
8615** determine exactly which parts of a database file are cached and for
8616** how long.
8617**
8618** The alternative page cache mechanism is an
8619** extreme measure that is only needed by the most demanding applications.
8620** The built-in page cache is recommended for most uses.
8621**
8622** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8623** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8624** the application may discard the parameter after the call to
8625** [sqlite3_config()] returns.)^
8626**
8627** [[the xInit() page cache method]]
8628** ^(The xInit() method is called once for each effective
8629** call to [sqlite3_initialize()])^
8630** (usually only once during the lifetime of the process). ^(The xInit()
8631** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
8632** The intent of the xInit() method is to set up global data structures
8633** required by the custom page cache implementation.
8634** ^(If the xInit() method is NULL, then the
8635** built-in default page cache is used instead of the application defined
8636** page cache.)^
8637**
8638** [[the xShutdown() page cache method]]
8639** ^The xShutdown() method is called by [sqlite3_shutdown()].
8640** It can be used to clean up
8641** any outstanding resources before process shutdown, if required.
8642** ^The xShutdown() method may be NULL.
8643**
8644** ^SQLite automatically serializes calls to the xInit method,
8645** so the xInit method need not be threadsafe. ^The
8646** xShutdown method is only called from [sqlite3_shutdown()] so it does
8647** not need to be threadsafe either. All other methods must be threadsafe
8648** in multithreaded applications.
8649**
8650** ^SQLite will never invoke xInit() more than once without an intervening
8651** call to xShutdown().
8652**
8653** [[the xCreate() page cache methods]]
8654** ^SQLite invokes the xCreate() method to construct a new cache instance.
8655** SQLite will typically create one cache instance for each open database file,
8656** though this is not guaranteed. ^The
8657** first parameter, szPage, is the size in bytes of the pages that must
8658** be allocated by the cache. ^szPage will always a power of two. ^The
8659** second parameter szExtra is a number of bytes of extra storage
8660** associated with each page cache entry. ^The szExtra parameter will
8661** a number less than 250. SQLite will use the
8662** extra szExtra bytes on each page to store metadata about the underlying
8663** database page on disk. The value passed into szExtra depends
8664** on the SQLite version, the target platform, and how SQLite was compiled.
8665** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8666** created will be used to cache database pages of a file stored on disk, or
8667** false if it is used for an in-memory database. The cache implementation
8668** does not have to do anything special based with the value of bPurgeable;
8669** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
8670** never invoke xUnpin() except to deliberately delete a page.
8671** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
8672** false will always have the "discard" flag set to true.
8673** ^Hence, a cache created with bPurgeable false will
8674** never contain any unpinned pages.
8675**
8676** [[the xCachesize() page cache method]]
8677** ^(The xCachesize() method may be called at any time by SQLite to set the
8678** suggested maximum cache-size (number of pages stored by) the cache
8679** instance passed as the first argument. This is the value configured using
8680** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
8681** parameter, the implementation is not required to do anything with this
8682** value; it is advisory only.
8683**
8684** [[the xPagecount() page cache methods]]
8685** The xPagecount() method must return the number of pages currently
8686** stored in the cache, both pinned and unpinned.
8687**
8688** [[the xFetch() page cache methods]]
8689** The xFetch() method locates a page in the cache and returns a pointer to
8690** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
8691** The pBuf element of the returned sqlite3_pcache_page object will be a
8692** pointer to a buffer of szPage bytes used to store the content of a
8693** single database page. The pExtra element of sqlite3_pcache_page will be
8694** a pointer to the szExtra bytes of extra storage that SQLite has requested
8695** for each entry in the page cache.
8696**
8697** The page to be fetched is determined by the key. ^The minimum key value
8698** is 1. After it has been retrieved using xFetch, the page is considered
8699** to be "pinned".
8700**
8701** If the requested page is already in the page cache, then the page cache
8702** implementation must return a pointer to the page buffer with its content
8703** intact. If the requested page is not already in the cache, then the
8704** cache implementation should use the value of the createFlag
8705** parameter to help it determined what action to take:
8706**
8707** <table border=1 width=85% align=center>
8708** <tr><th> createFlag <th> Behavior when page is not already in cache
8709** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
8710** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
8711** Otherwise return NULL.
8712** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
8713** NULL if allocating a new page is effectively impossible.
8714** </table>
8715**
8716** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
8717** will only use a createFlag of 2 after a prior call with a createFlag of 1
8718** failed.)^ In between the xFetch() calls, SQLite may
8719** attempt to unpin one or more cache pages by spilling the content of
8720** pinned pages to disk and synching the operating system disk cache.
8721**
8722** [[the xUnpin() page cache method]]
8723** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
8724** as its second argument. If the third parameter, discard, is non-zero,
8725** then the page must be evicted from the cache.
8726** ^If the discard parameter is
8727** zero, then the page may be discarded or retained at the discretion of
8728** page cache implementation. ^The page cache implementation
8729** may choose to evict unpinned pages at any time.
8730**
8731** The cache must not perform any reference counting. A single
8732** call to xUnpin() unpins the page regardless of the number of prior calls
8733** to xFetch().
8734**
8735** [[the xRekey() page cache methods]]
8736** The xRekey() method is used to change the key value associated with the
8737** page passed as the second argument. If the cache
8738** previously contains an entry associated with newKey, it must be
8739** discarded. ^Any prior cache entry associated with newKey is guaranteed not
8740** to be pinned.
8741**
8742** When SQLite calls the xTruncate() method, the cache must discard all
8743** existing cache entries with page numbers (keys) greater than or equal
8744** to the value of the iLimit parameter passed to xTruncate(). If any
8745** of these pages are pinned, they are implicitly unpinned, meaning that
8746** they can be safely discarded.
8747**
8748** [[the xDestroy() page cache method]]
8749** ^The xDestroy() method is used to delete a cache allocated by xCreate().
8750** All resources associated with the specified cache should be freed. ^After
8751** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
8752** handle invalid, and will not use it with any other sqlite3_pcache_methods2
8753** functions.
8754**
8755** [[the xShrink() page cache method]]
8756** ^SQLite invokes the xShrink() method when it wants the page cache to
8757** free up as much of heap memory as possible. The page cache implementation
8758** is not obligated to free any memory, but well-behaved implementations should
8759** do their best.
8760*/
8761typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
8762struct sqlite3_pcache_methods2 {
8763 int iVersion;
8764 void *pArg;
8765 int (*xInit)(void*);
8766 void (*xShutdown)(void*);
8767 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
8768 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8769 int (*xPagecount)(sqlite3_pcache*);
8770 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8771 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
8772 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
8773 unsigned oldKey, unsigned newKey);
8774 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8775 void (*xDestroy)(sqlite3_pcache*);
8776 void (*xShrink)(sqlite3_pcache*);
8777};
8778
8779/*
8780** This is the obsolete pcache_methods object that has now been replaced
8781** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
8782** retained in the header file for backwards compatibility only.
8783*/
8784typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
8785struct sqlite3_pcache_methods {
8786 void *pArg;
8787 int (*xInit)(void*);
8788 void (*xShutdown)(void*);
8789 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
8790 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
8791 int (*xPagecount)(sqlite3_pcache*);
8792 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
8793 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
8794 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
8795 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
8796 void (*xDestroy)(sqlite3_pcache*);
8797};
8798
8799
8800/*
8801** CAPI3REF: Online Backup Object
8802**
8803** The sqlite3_backup object records state information about an ongoing
8804** online backup operation. ^The sqlite3_backup object is created by
8805** a call to [sqlite3_backup_init()] and is destroyed by a call to
8806** [sqlite3_backup_finish()].
8807**
8808** See Also: [Using the SQLite Online Backup API]
8809*/
8810typedef struct sqlite3_backup sqlite3_backup;
8811
8812/*
8813** CAPI3REF: Online Backup API.
8814**
8815** The backup API copies the content of one database into another.
8816** It is useful either for creating backups of databases or
8817** for copying in-memory databases to or from persistent files.
8818**
8819** See Also: [Using the SQLite Online Backup API]
8820**
8821** ^SQLite holds a write transaction open on the destination database file
8822** for the duration of the backup operation.
8823** ^The source database is read-locked only while it is being read;
8824** it is not locked continuously for the entire backup operation.
8825** ^Thus, the backup may be performed on a live source database without
8826** preventing other database connections from
8827** reading or writing to the source database while the backup is underway.
8828**
8829** ^(To perform a backup operation:
8830** <ol>
8831** <li><b>sqlite3_backup_init()</b> is called once to initialize the
8832** backup,
8833** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
8834** the data between the two databases, and finally
8835** <li><b>sqlite3_backup_finish()</b> is called to release all resources
8836** associated with the backup operation.
8837** </ol>)^
8838** There should be exactly one call to sqlite3_backup_finish() for each
8839** successful call to sqlite3_backup_init().
8840**
8841** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
8842**
8843** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
8844** [database connection] associated with the destination database
8845** and the database name, respectively.
8846** ^The database name is "main" for the main database, "temp" for the
8847** temporary database, or the name specified after the AS keyword in
8848** an [ATTACH] statement for an attached database.
8849** ^The S and M arguments passed to
8850** sqlite3_backup_init(D,N,S,M) identify the [database connection]
8851** and database name of the source database, respectively.
8852** ^The source and destination [database connections] (parameters S and D)
8853** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
8854** an error.
8855**
8856** ^A call to sqlite3_backup_init() will fail, returning NULL, if
8857** there is already a read or read-write transaction open on the
8858** destination database.
8859**
8860** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
8861** returned and an error code and error message are stored in the
8862** destination [database connection] D.
8863** ^The error code and message for the failed call to sqlite3_backup_init()
8864** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
8865** [sqlite3_errmsg16()] functions.
8866** ^A successful call to sqlite3_backup_init() returns a pointer to an
8867** [sqlite3_backup] object.
8868** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
8869** sqlite3_backup_finish() functions to perform the specified backup
8870** operation.
8871**
8872** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
8873**
8874** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
8875** the source and destination databases specified by [sqlite3_backup] object B.
8876** ^If N is negative, all remaining source pages are copied.
8877** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
8878** are still more pages to be copied, then the function returns [SQLITE_OK].
8879** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
8880** from source to destination, then it returns [SQLITE_DONE].
8881** ^If an error occurs while running sqlite3_backup_step(B,N),
8882** then an [error code] is returned. ^As well as [SQLITE_OK] and
8883** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
8884** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
8885** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
8886**
8887** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
8888** <ol>
8889** <li> the destination database was opened read-only, or
8890** <li> the destination database is using write-ahead-log journaling
8891** and the destination and source page sizes differ, or
8892** <li> the destination database is an in-memory database and the
8893** destination and source page sizes differ.
8894** </ol>)^
8895**
8896** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
8897** the [sqlite3_busy_handler | busy-handler function]
8898** is invoked (if one is specified). ^If the
8899** busy-handler returns non-zero before the lock is available, then
8900** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
8901** sqlite3_backup_step() can be retried later. ^If the source
8902** [database connection]
8903** is being used to write to the source database when sqlite3_backup_step()
8904** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
8905** case the call to sqlite3_backup_step() can be retried later on. ^(If
8906** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
8907** [SQLITE_READONLY] is returned, then
8908** there is no point in retrying the call to sqlite3_backup_step(). These
8909** errors are considered fatal.)^ The application must accept
8910** that the backup operation has failed and pass the backup operation handle
8911** to the sqlite3_backup_finish() to release associated resources.
8912**
8913** ^The first call to sqlite3_backup_step() obtains an exclusive lock
8914** on the destination file. ^The exclusive lock is not released until either
8915** sqlite3_backup_finish() is called or the backup operation is complete
8916** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
8917** sqlite3_backup_step() obtains a [shared lock] on the source database that
8918** lasts for the duration of the sqlite3_backup_step() call.
8919** ^Because the source database is not locked between calls to
8920** sqlite3_backup_step(), the source database may be modified mid-way
8921** through the backup process. ^If the source database is modified by an
8922** external process or via a database connection other than the one being
8923** used by the backup operation, then the backup will be automatically
8924** restarted by the next call to sqlite3_backup_step(). ^If the source
8925** database is modified by the using the same database connection as is used
8926** by the backup operation, then the backup database is automatically
8927** updated at the same time.
8928**
8929** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
8930**
8931** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
8932** application wishes to abandon the backup operation, the application
8933** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
8934** ^The sqlite3_backup_finish() interfaces releases all
8935** resources associated with the [sqlite3_backup] object.
8936** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
8937** active write-transaction on the destination database is rolled back.
8938** The [sqlite3_backup] object is invalid
8939** and may not be used following a call to sqlite3_backup_finish().
8940**
8941** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
8942** sqlite3_backup_step() errors occurred, regardless or whether or not
8943** sqlite3_backup_step() completed.
8944** ^If an out-of-memory condition or IO error occurred during any prior
8945** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
8946** sqlite3_backup_finish() returns the corresponding [error code].
8947**
8948** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
8949** is not a permanent error and does not affect the return value of
8950** sqlite3_backup_finish().
8951**
8952** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
8953** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
8954**
8955** ^The sqlite3_backup_remaining() routine returns the number of pages still
8956** to be backed up at the conclusion of the most recent sqlite3_backup_step().
8957** ^The sqlite3_backup_pagecount() routine returns the total number of pages
8958** in the source database at the conclusion of the most recent
8959** sqlite3_backup_step().
8960** ^(The values returned by these functions are only updated by
8961** sqlite3_backup_step(). If the source database is modified in a way that
8962** changes the size of the source database or the number of pages remaining,
8963** those changes are not reflected in the output of sqlite3_backup_pagecount()
8964** and sqlite3_backup_remaining() until after the next
8965** sqlite3_backup_step().)^
8966**
8967** <b>Concurrent Usage of Database Handles</b>
8968**
8969** ^The source [database connection] may be used by the application for other
8970** purposes while a backup operation is underway or being initialized.
8971** ^If SQLite is compiled and configured to support threadsafe database
8972** connections, then the source database connection may be used concurrently
8973** from within other threads.
8974**
8975** However, the application must guarantee that the destination
8976** [database connection] is not passed to any other API (by any thread) after
8977** sqlite3_backup_init() is called and before the corresponding call to
8978** sqlite3_backup_finish(). SQLite does not currently check to see
8979** if the application incorrectly accesses the destination [database connection]
8980** and so no error code is reported, but the operations may malfunction
8981** nevertheless. Use of the destination database connection while a
8982** backup is in progress might also also cause a mutex deadlock.
8983**
8984** If running in [shared cache mode], the application must
8985** guarantee that the shared cache used by the destination database
8986** is not accessed while the backup is running. In practice this means
8987** that the application must guarantee that the disk file being
8988** backed up to is not accessed by any connection within the process,
8989** not just the specific connection that was passed to sqlite3_backup_init().
8990**
8991** The [sqlite3_backup] object itself is partially threadsafe. Multiple
8992** threads may safely make multiple concurrent calls to sqlite3_backup_step().
8993** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
8994** APIs are not strictly speaking threadsafe. If they are invoked at the
8995** same time as another thread is invoking sqlite3_backup_step() it is
8996** possible that they return invalid values.
8997*/
8998SQLITE_API sqlite3_backup *sqlite3_backup_init(
8999 sqlite3 *pDest, /* Destination database handle */
9000 const char *zDestName, /* Destination database name */
9001 sqlite3 *pSource, /* Source database handle */
9002 const char *zSourceName /* Source database name */
9003);
9004SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9005SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9006SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9007SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9008
9009/*
9010** CAPI3REF: Unlock Notification
9011** METHOD: sqlite3
9012**
9013** ^When running in shared-cache mode, a database operation may fail with
9014** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9015** individual tables within the shared-cache cannot be obtained. See
9016** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9017** ^This API may be used to register a callback that SQLite will invoke
9018** when the connection currently holding the required lock relinquishes it.
9019** ^This API is only available if the library was compiled with the
9020** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9021**
9022** See Also: [Using the SQLite Unlock Notification Feature].
9023**
9024** ^Shared-cache locks are released when a database connection concludes
9025** its current transaction, either by committing it or rolling it back.
9026**
9027** ^When a connection (known as the blocked connection) fails to obtain a
9028** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9029** identity of the database connection (the blocking connection) that
9030** has locked the required resource is stored internally. ^After an
9031** application receives an SQLITE_LOCKED error, it may call the
9032** sqlite3_unlock_notify() method with the blocked connection handle as
9033** the first argument to register for a callback that will be invoked
9034** when the blocking connections current transaction is concluded. ^The
9035** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9036** call that concludes the blocking connection's transaction.
9037**
9038** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9039** there is a chance that the blocking connection will have already
9040** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9041** If this happens, then the specified callback is invoked immediately,
9042** from within the call to sqlite3_unlock_notify().)^
9043**
9044** ^If the blocked connection is attempting to obtain a write-lock on a
9045** shared-cache table, and more than one other connection currently holds
9046** a read-lock on the same table, then SQLite arbitrarily selects one of
9047** the other connections to use as the blocking connection.
9048**
9049** ^(There may be at most one unlock-notify callback registered by a
9050** blocked connection. If sqlite3_unlock_notify() is called when the
9051** blocked connection already has a registered unlock-notify callback,
9052** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9053** called with a NULL pointer as its second argument, then any existing
9054** unlock-notify callback is canceled. ^The blocked connections
9055** unlock-notify callback may also be canceled by closing the blocked
9056** connection using [sqlite3_close()].
9057**
9058** The unlock-notify callback is not reentrant. If an application invokes
9059** any sqlite3_xxx API functions from within an unlock-notify callback, a
9060** crash or deadlock may be the result.
9061**
9062** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9063** returns SQLITE_OK.
9064**
9065** <b>Callback Invocation Details</b>
9066**
9067** When an unlock-notify callback is registered, the application provides a
9068** single void* pointer that is passed to the callback when it is invoked.
9069** However, the signature of the callback function allows SQLite to pass
9070** it an array of void* context pointers. The first argument passed to
9071** an unlock-notify callback is a pointer to an array of void* pointers,
9072** and the second is the number of entries in the array.
9073**
9074** When a blocking connection's transaction is concluded, there may be
9075** more than one blocked connection that has registered for an unlock-notify
9076** callback. ^If two or more such blocked connections have specified the
9077** same callback function, then instead of invoking the callback function
9078** multiple times, it is invoked once with the set of void* context pointers
9079** specified by the blocked connections bundled together into an array.
9080** This gives the application an opportunity to prioritize any actions
9081** related to the set of unblocked database connections.
9082**
9083** <b>Deadlock Detection</b>
9084**
9085** Assuming that after registering for an unlock-notify callback a
9086** database waits for the callback to be issued before taking any further
9087** action (a reasonable assumption), then using this API may cause the
9088** application to deadlock. For example, if connection X is waiting for
9089** connection Y's transaction to be concluded, and similarly connection
9090** Y is waiting on connection X's transaction, then neither connection
9091** will proceed and the system may remain deadlocked indefinitely.
9092**
9093** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9094** detection. ^If a given call to sqlite3_unlock_notify() would put the
9095** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9096** unlock-notify callback is registered. The system is said to be in
9097** a deadlocked state if connection A has registered for an unlock-notify
9098** callback on the conclusion of connection B's transaction, and connection
9099** B has itself registered for an unlock-notify callback when connection
9100** A's transaction is concluded. ^Indirect deadlock is also detected, so
9101** the system is also considered to be deadlocked if connection B has
9102** registered for an unlock-notify callback on the conclusion of connection
9103** C's transaction, where connection C is waiting on connection A. ^Any
9104** number of levels of indirection are allowed.
9105**
9106** <b>The "DROP TABLE" Exception</b>
9107**
9108** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9109** always appropriate to call sqlite3_unlock_notify(). There is however,
9110** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9111** SQLite checks if there are any currently executing SELECT statements
9112** that belong to the same connection. If there are, SQLITE_LOCKED is
9113** returned. In this case there is no "blocking connection", so invoking
9114** sqlite3_unlock_notify() results in the unlock-notify callback being
9115** invoked immediately. If the application then re-attempts the "DROP TABLE"
9116** or "DROP INDEX" query, an infinite loop might be the result.
9117**
9118** One way around this problem is to check the extended error code returned
9119** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9120** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9121** the special "DROP TABLE/INDEX" case, the extended error code is just
9122** SQLITE_LOCKED.)^
9123*/
9124SQLITE_API int sqlite3_unlock_notify(
9125 sqlite3 *pBlocked, /* Waiting connection */
9126 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9127 void *pNotifyArg /* Argument to pass to xNotify */
9128);
9129
9130
9131/*
9132** CAPI3REF: String Comparison
9133**
9134** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9135** and extensions to compare the contents of two buffers containing UTF-8
9136** strings in a case-independent fashion, using the same definition of "case
9137** independence" that SQLite uses internally when comparing identifiers.
9138*/
9139SQLITE_API int sqlite3_stricmp(const char *, const char *);
9140SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9141
9142/*
9143** CAPI3REF: String Globbing
9144*
9145** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9146** string X matches the [GLOB] pattern P.
9147** ^The definition of [GLOB] pattern matching used in
9148** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9149** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9150** is case sensitive.
9151**
9152** Note that this routine returns zero on a match and non-zero if the strings
9153** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9154**
9155** See also: [sqlite3_strlike()].
9156*/
9157SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9158
9159/*
9160** CAPI3REF: String LIKE Matching
9161*
9162** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9163** string X matches the [LIKE] pattern P with escape character E.
9164** ^The definition of [LIKE] pattern matching used in
9165** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9166** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9167** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9168** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9169** insensitive - equivalent upper and lower case ASCII characters match
9170** one another.
9171**
9172** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9173** only ASCII characters are case folded.
9174**
9175** Note that this routine returns zero on a match and non-zero if the strings
9176** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9177**
9178** See also: [sqlite3_strglob()].
9179*/
9180SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9181
9182/*
9183** CAPI3REF: Error Logging Interface
9184**
9185** ^The [sqlite3_log()] interface writes a message into the [error log]
9186** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9187** ^If logging is enabled, the zFormat string and subsequent arguments are
9188** used with [sqlite3_snprintf()] to generate the final output string.
9189**
9190** The sqlite3_log() interface is intended for use by extensions such as
9191** virtual tables, collating functions, and SQL functions. While there is
9192** nothing to prevent an application from calling sqlite3_log(), doing so
9193** is considered bad form.
9194**
9195** The zFormat string must not be NULL.
9196**
9197** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9198** will not use dynamically allocated memory. The log message is stored in
9199** a fixed-length buffer on the stack. If the log message is longer than
9200** a few hundred characters, it will be truncated to the length of the
9201** buffer.
9202*/
9203SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9204
9205/*
9206** CAPI3REF: Write-Ahead Log Commit Hook
9207** METHOD: sqlite3
9208**
9209** ^The [sqlite3_wal_hook()] function is used to register a callback that
9210** is invoked each time data is committed to a database in wal mode.
9211**
9212** ^(The callback is invoked by SQLite after the commit has taken place and
9213** the associated write-lock on the database released)^, so the implementation
9214** may read, write or [checkpoint] the database as required.
9215**
9216** ^The first parameter passed to the callback function when it is invoked
9217** is a copy of the third parameter passed to sqlite3_wal_hook() when
9218** registering the callback. ^The second is a copy of the database handle.
9219** ^The third parameter is the name of the database that was written to -
9220** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9221** is the number of pages currently in the write-ahead log file,
9222** including those that were just committed.
9223**
9224** The callback function should normally return [SQLITE_OK]. ^If an error
9225** code is returned, that error will propagate back up through the
9226** SQLite code base to cause the statement that provoked the callback
9227** to report an error, though the commit will have still occurred. If the
9228** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9229** that does not correspond to any valid SQLite error code, the results
9230** are undefined.
9231**
9232** A single database handle may have at most a single write-ahead log callback
9233** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9234** previously registered write-ahead log callback. ^The return value is
9235** a copy of the third parameter from the previous call, if any, or 0.
9236** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9237** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9238** overwrite any prior [sqlite3_wal_hook()] settings.
9239*/
9240SQLITE_API void *sqlite3_wal_hook(
9241 sqlite3*,
9242 int(*)(void *,sqlite3*,const char*,int),
9243 void*
9244);
9245
9246/*
9247** CAPI3REF: Configure an auto-checkpoint
9248** METHOD: sqlite3
9249**
9250** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9251** [sqlite3_wal_hook()] that causes any database on [database connection] D
9252** to automatically [checkpoint]
9253** after committing a transaction if there are N or
9254** more frames in the [write-ahead log] file. ^Passing zero or
9255** a negative value as the nFrame parameter disables automatic
9256** checkpoints entirely.
9257**
9258** ^The callback registered by this function replaces any existing callback
9259** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9260** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9261** configured by this function.
9262**
9263** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9264** from SQL.
9265**
9266** ^Checkpoints initiated by this mechanism are
9267** [sqlite3_wal_checkpoint_v2|PASSIVE].
9268**
9269** ^Every new [database connection] defaults to having the auto-checkpoint
9270** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9271** pages. The use of this interface
9272** is only necessary if the default setting is found to be suboptimal
9273** for a particular application.
9274*/
9275SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9276
9277/*
9278** CAPI3REF: Checkpoint a database
9279** METHOD: sqlite3
9280**
9281** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9282** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9283**
9284** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9285** [write-ahead log] for database X on [database connection] D to be
9286** transferred into the database file and for the write-ahead log to
9287** be reset. See the [checkpointing] documentation for addition
9288** information.
9289**
9290** This interface used to be the only way to cause a checkpoint to
9291** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9292** interface was added. This interface is retained for backwards
9293** compatibility and as a convenience for applications that need to manually
9294** start a callback but which do not need the full power (and corresponding
9295** complication) of [sqlite3_wal_checkpoint_v2()].
9296*/
9297SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9298
9299/*
9300** CAPI3REF: Checkpoint a database
9301** METHOD: sqlite3
9302**
9303** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9304** operation on database X of [database connection] D in mode M. Status
9305** information is written back into integers pointed to by L and C.)^
9306** ^(The M parameter must be a valid [checkpoint mode]:)^
9307**
9308** <dl>
9309** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9310** ^Checkpoint as many frames as possible without waiting for any database
9311** readers or writers to finish, then sync the database file if all frames
9312** in the log were checkpointed. ^The [busy-handler callback]
9313** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9314** ^On the other hand, passive mode might leave the checkpoint unfinished
9315** if there are concurrent readers or writers.
9316**
9317** <dt>SQLITE_CHECKPOINT_FULL<dd>
9318** ^This mode blocks (it invokes the
9319** [sqlite3_busy_handler|busy-handler callback]) until there is no
9320** database writer and all readers are reading from the most recent database
9321** snapshot. ^It then checkpoints all frames in the log file and syncs the
9322** database file. ^This mode blocks new database writers while it is pending,
9323** but new database readers are allowed to continue unimpeded.
9324**
9325** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9326** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9327** that after checkpointing the log file it blocks (calls the
9328** [busy-handler callback])
9329** until all readers are reading from the database file only. ^This ensures
9330** that the next writer will restart the log file from the beginning.
9331** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9332** database writer attempts while it is pending, but does not impede readers.
9333**
9334** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9335** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9336** addition that it also truncates the log file to zero bytes just prior
9337** to a successful return.
9338** </dl>
9339**
9340** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9341** the log file or to -1 if the checkpoint could not run because
9342** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9343** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9344** log file (including any that were already checkpointed before the function
9345** was called) or to -1 if the checkpoint could not run due to an error or
9346** because the database is not in WAL mode. ^Note that upon successful
9347** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9348** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9349**
9350** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9351** any other process is running a checkpoint operation at the same time, the
9352** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9353** busy-handler configured, it will not be invoked in this case.
9354**
9355** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9356** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9357** obtained immediately, and a busy-handler is configured, it is invoked and
9358** the writer lock retried until either the busy-handler returns 0 or the lock
9359** is successfully obtained. ^The busy-handler is also invoked while waiting for
9360** database readers as described above. ^If the busy-handler returns 0 before
9361** the writer lock is obtained or while waiting for database readers, the
9362** checkpoint operation proceeds from that point in the same way as
9363** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9364** without blocking any further. ^SQLITE_BUSY is returned in this case.
9365**
9366** ^If parameter zDb is NULL or points to a zero length string, then the
9367** specified operation is attempted on all WAL databases [attached] to
9368** [database connection] db. In this case the
9369** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9370** an SQLITE_BUSY error is encountered when processing one or more of the
9371** attached WAL databases, the operation is still attempted on any remaining
9372** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9373** error occurs while processing an attached database, processing is abandoned
9374** and the error code is returned to the caller immediately. ^If no error
9375** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9376** databases, SQLITE_OK is returned.
9377**
9378** ^If database zDb is the name of an attached database that is not in WAL
9379** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9380** zDb is not NULL (or a zero length string) and is not the name of any
9381** attached database, SQLITE_ERROR is returned to the caller.
9382**
9383** ^Unless it returns SQLITE_MISUSE,
9384** the sqlite3_wal_checkpoint_v2() interface
9385** sets the error information that is queried by
9386** [sqlite3_errcode()] and [sqlite3_errmsg()].
9387**
9388** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9389** from SQL.
9390*/
9391SQLITE_API int sqlite3_wal_checkpoint_v2(
9392 sqlite3 *db, /* Database handle */
9393 const char *zDb, /* Name of attached database (or NULL) */
9394 int eMode, /* SQLITE_CHECKPOINT_* value */
9395 int *pnLog, /* OUT: Size of WAL log in frames */
9396 int *pnCkpt /* OUT: Total number of frames checkpointed */
9397);
9398
9399/*
9400** CAPI3REF: Checkpoint Mode Values
9401** KEYWORDS: {checkpoint mode}
9402**
9403** These constants define all valid values for the "checkpoint mode" passed
9404** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9405** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9406** meaning of each of these checkpoint modes.
9407*/
9408#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9409#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9410#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
9411#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9412
9413/*
9414** CAPI3REF: Virtual Table Interface Configuration
9415**
9416** This function may be called by either the [xConnect] or [xCreate] method
9417** of a [virtual table] implementation to configure
9418** various facets of the virtual table interface.
9419**
9420** If this interface is invoked outside the context of an xConnect or
9421** xCreate virtual table method then the behavior is undefined.
9422**
9423** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9424** [database connection] in which the virtual table is being created and
9425** which is passed in as the first argument to the [xConnect] or [xCreate]
9426** method that is invoking sqlite3_vtab_config(). The C parameter is one
9427** of the [virtual table configuration options]. The presence and meaning
9428** of parameters after C depend on which [virtual table configuration option]
9429** is used.
9430*/
9431SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9432
9433/*
9434** CAPI3REF: Virtual Table Configuration Options
9435** KEYWORDS: {virtual table configuration options}
9436** KEYWORDS: {virtual table configuration option}
9437**
9438** These macros define the various options to the
9439** [sqlite3_vtab_config()] interface that [virtual table] implementations
9440** can use to customize and optimize their behavior.
9441**
9442** <dl>
9443** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9444** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
9445** <dd>Calls of the form
9446** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9447** where X is an integer. If X is zero, then the [virtual table] whose
9448** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9449** support constraints. In this configuration (which is the default) if
9450** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9451** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9452** specified as part of the users SQL statement, regardless of the actual
9453** ON CONFLICT mode specified.
9454**
9455** If X is non-zero, then the virtual table implementation guarantees
9456** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9457** any modifications to internal or persistent data structures have been made.
9458** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
9459** is able to roll back a statement or database transaction, and abandon
9460** or continue processing the current SQL statement as appropriate.
9461** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9462** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9463** had been ABORT.
9464**
9465** Virtual table implementations that are required to handle OR REPLACE
9466** must do so within the [xUpdate] method. If a call to the
9467** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9468** CONFLICT policy is REPLACE, the virtual table implementation should
9469** silently replace the appropriate rows within the xUpdate callback and
9470** return SQLITE_OK. Or, if this is not possible, it may return
9471** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
9472** constraint handling.
9473** </dd>
9474**
9475** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9476** <dd>Calls of the form
9477** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9478** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9479** prohibits that virtual table from being used from within triggers and
9480** views.
9481** </dd>
9482**
9483** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9484** <dd>Calls of the form
9485** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9486** the [xConnect] or [xCreate] methods of a [virtual table] implmentation
9487** identify that virtual table as being safe to use from within triggers
9488** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9489** virtual table can do no serious harm even if it is controlled by a
9490** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9491** flag unless absolutely necessary.
9492** </dd>
9493** </dl>
9494*/
9495#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
9496#define SQLITE_VTAB_INNOCUOUS 2
9497#define SQLITE_VTAB_DIRECTONLY 3
9498
9499/*
9500** CAPI3REF: Determine The Virtual Table Conflict Policy
9501**
9502** This function may only be called from within a call to the [xUpdate] method
9503** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9504** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9505** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9506** of the SQL statement that triggered the call to the [xUpdate] method of the
9507** [virtual table].
9508*/
9509SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9510
9511/*
9512** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9513**
9514** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
9515** method of a [virtual table], then it might return true if the
9516** column is being fetched as part of an UPDATE operation during which the
9517** column value will not change. The virtual table implementation can use
9518** this hint as permission to substitute a return value that is less
9519** expensive to compute and that the corresponding
9520** [xUpdate] method understands as a "no-change" value.
9521**
9522** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9523** the column is not changed by the UPDATE statement, then the xColumn
9524** method can optionally return without setting a result, without calling
9525** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9526** In that case, [sqlite3_value_nochange(X)] will return true for the
9527** same column in the [xUpdate] method.
9528**
9529** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
9530** implementations should continue to give a correct answer even if the
9531** sqlite3_vtab_nochange() interface were to always return false. In the
9532** current implementation, the sqlite3_vtab_nochange() interface does always
9533** returns false for the enhanced [UPDATE FROM] statement.
9534*/
9535SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9536
9537/*
9538** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9539** METHOD: sqlite3_index_info
9540**
9541** This function may only be called from within a call to the [xBestIndex]
9542** method of a [virtual table]. This function returns a pointer to a string
9543** that is the name of the appropriate collation sequence to use for text
9544** comparisons on the constraint identified by its arguments.
9545**
9546** The first argument must be the pointer to the [sqlite3_index_info] object
9547** that is the first parameter to the xBestIndex() method. The second argument
9548** must be an index into the aConstraint[] array belonging to the
9549** sqlite3_index_info structure passed to xBestIndex.
9550**
9551** Important:
9552** The first parameter must be the same pointer that is passed into the
9553** xBestMethod() method. The first parameter may not be a pointer to a
9554** different [sqlite3_index_info] object, even an exact copy.
9555**
9556** The return value is computed as follows:
9557**
9558** <ol>
9559** <li><p> If the constraint comes from a WHERE clause expression that contains
9560** a [COLLATE operator], then the name of the collation specified by
9561** that COLLATE operator is returned.
9562** <li><p> If there is no COLLATE operator, but the column that is the subject
9563** of the constraint specifies an alternative collating sequence via
9564** a [COLLATE clause] on the column definition within the CREATE TABLE
9565** statement that was passed into [sqlite3_declare_vtab()], then the
9566** name of that alternative collating sequence is returned.
9567** <li><p> Otherwise, "BINARY" is returned.
9568** </ol>
9569*/
9570SQLITE_API SQLITE_EXPERIMENTAL const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9571
9572/*
9573** CAPI3REF: Determine if a virtual table query is DISTINCT
9574** METHOD: sqlite3_index_info
9575**
9576** This API may only be used from within an [xBestIndex|xBestIndex method]
9577** of a [virtual table] implementation. The result of calling this
9578** interface from outside of xBestIndex() is undefined and probably harmful.
9579**
9580** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
9581** 3. The integer returned by sqlite3_vtab_distinct()
9582** gives the virtual table additional information about how the query
9583** planner wants the output to be ordered. As long as the virtual table
9584** can meet the ordering requirements of the query planner, it may set
9585** the "orderByConsumed" flag.
9586**
9587** <ol><li value="0"><p>
9588** ^If the sqlite3_vtab_distinct() interface returns 0, that means
9589** that the query planner needs the virtual table to return all rows in the
9590** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
9591** [sqlite3_index_info] object. This is the default expectation. If the
9592** virtual table outputs all rows in sorted order, then it is always safe for
9593** the xBestIndex method to set the "orderByConsumed" flag, regardless of
9594** the return value from sqlite3_vtab_distinct().
9595** <li value="1"><p>
9596** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
9597** that the query planner does not need the rows to be returned in sorted order
9598** as long as all rows with the same values in all columns identified by the
9599** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
9600** is doing a GROUP BY.
9601** <li value="2"><p>
9602** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
9603** that the query planner does not need the rows returned in any particular
9604** order, as long as rows with the same values in all "aOrderBy" columns
9605** are adjacent.)^ ^(Furthermore, only a single row for each particular
9606** combination of values in the columns identified by the "aOrderBy" field
9607** needs to be returned.)^ ^It is always ok for two or more rows with the same
9608** values in all "aOrderBy" columns to be returned, as long as all such rows
9609** are adjacent. ^The virtual table may, if it chooses, omit extra rows
9610** that have the same value for all columns identified by "aOrderBy".
9611** ^However omitting the extra rows is optional.
9612** This mode is used for a DISTINCT query.
9613** <li value="3"><p>
9614** ^(If the sqlite3_vtab_distinct() interface returns 3, that means
9615** that the query planner needs only distinct rows but it does need the
9616** rows to be sorted.)^ ^The virtual table implementation is free to omit
9617** rows that are identical in all aOrderBy columns, if it wants to, but
9618** it is not required to omit any rows. This mode is used for queries
9619** that have both DISTINCT and ORDER BY clauses.
9620** </ol>
9621**
9622** ^For the purposes of comparing virtual table output values to see if the
9623** values are same value for sorting purposes, two NULL values are considered
9624** to be the same. In other words, the comparison operator is "IS"
9625** (or "IS NOT DISTINCT FROM") and not "==".
9626**
9627** If a virtual table implementation is unable to meet the requirements
9628** specified above, then it must not set the "orderByConsumed" flag in the
9629** [sqlite3_index_info] object or an incorrect answer may result.
9630**
9631** ^A virtual table implementation is always free to return rows in any order
9632** it wants, as long as the "orderByConsumed" flag is not set. ^When the
9633** the "orderByConsumed" flag is unset, the query planner will add extra
9634** [bytecode] to ensure that the final results returned by the SQL query are
9635** ordered correctly. The use of the "orderByConsumed" flag and the
9636** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
9637** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
9638** flag might help queries against a virtual table to run faster. Being
9639** overly aggressive and setting the "orderByConsumed" flag when it is not
9640** valid to do so, on the other hand, might cause SQLite to return incorrect
9641** results.
9642*/
9643SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
9644
9645/*
9646** CAPI3REF: Identify and handle IN constraints in xBestIndex
9647**
9648** This interface may only be used from within an
9649** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
9650** The result of invoking this interface from any other context is
9651** undefined and probably harmful.
9652**
9653** ^(A constraint on a virtual table of the form
9654** "[IN operator|column IN (...)]" is
9655** communicated to the xBestIndex method as a
9656** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
9657** this constraint, it must set the corresponding
9658** aConstraintUsage[].argvIndex to a postive integer. ^(Then, under
9659** the usual mode of handling IN operators, SQLite generates [bytecode]
9660** that invokes the [xFilter|xFilter() method] once for each value
9661** on the right-hand side of the IN operator.)^ Thus the virtual table
9662** only sees a single value from the right-hand side of the IN operator
9663** at a time.
9664**
9665** In some cases, however, it would be advantageous for the virtual
9666** table to see all values on the right-hand of the IN operator all at
9667** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
9668**
9669** <ol>
9670** <li><p>
9671** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
9672** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
9673** is an [IN operator] that can be processed all at once. ^In other words,
9674** sqlite3_vtab_in() with -1 in the third argument is a mechanism
9675** by which the virtual table can ask SQLite if all-at-once processing
9676** of the IN operator is even possible.
9677**
9678** <li><p>
9679** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
9680** to SQLite that the virtual table does or does not want to process
9681** the IN operator all-at-once, respectively. ^Thus when the third
9682** parameter (F) is non-negative, this interface is the mechanism by
9683** which the virtual table tells SQLite how it wants to process the
9684** IN operator.
9685** </ol>
9686**
9687** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
9688** within the same xBestIndex method call. ^For any given P,N pair,
9689** the return value from sqlite3_vtab_in(P,N,F) will always be the same
9690** within the same xBestIndex call. ^If the interface returns true
9691** (non-zero), that means that the constraint is an IN operator
9692** that can be processed all-at-once. ^If the constraint is not an IN
9693** operator or cannot be processed all-at-once, then the interface returns
9694** false.
9695**
9696** ^(All-at-once processing of the IN operator is selected if both of the
9697** following conditions are met:
9698**
9699** <ol>
9700** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
9701** integer. This is how the virtual table tells SQLite that it wants to
9702** use the N-th constraint.
9703**
9704** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
9705** non-negative had F>=1.
9706** </ol>)^
9707**
9708** ^If either or both of the conditions above are false, then SQLite uses
9709** the traditional one-at-a-time processing strategy for the IN constraint.
9710** ^If both conditions are true, then the argvIndex-th parameter to the
9711** xFilter method will be an [sqlite3_value] that appears to be NULL,
9712** but which can be passed to [sqlite3_vtab_in_first()] and
9713** [sqlite3_vtab_in_next()] to find all values on the right-hand side
9714** of the IN constraint.
9715*/
9716SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
9717
9718/*
9719** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
9720**
9721** These interfaces are only useful from within the
9722** [xFilter|xFilter() method] of a [virtual table] implementation.
9723** The result of invoking these interfaces from any other context
9724** is undefined and probably harmful.
9725**
9726** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
9727** sqlite3_vtab_in_next(X,P) must be one of the parameters to the
9728** xFilter method which invokes these routines, and specifically
9729** a parameter that was previously selected for all-at-once IN constraint
9730** processing use the [sqlite3_vtab_in()] interface in the
9731** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
9732** an xFilter argument that was selected for all-at-once IN constraint
9733** processing, then these routines return [SQLITE_MISUSE])^ or perhaps
9734** exhibit some other undefined or harmful behavior.
9735**
9736** ^(Use these routines to access all values on the right-hand side
9737** of the IN constraint using code like the following:
9738**
9739** <blockquote><pre>
9740** &nbsp; for(rc=sqlite3_vtab_in_first(pList, &pVal);
9741** &nbsp; rc==SQLITE_OK && pVal
9742** &nbsp; rc=sqlite3_vtab_in_next(pList, &pVal)
9743** &nbsp; ){
9744** &nbsp; // do something with pVal
9745** &nbsp; }
9746** &nbsp; if( rc!=SQLITE_OK ){
9747** &nbsp; // an error has occurred
9748** &nbsp; }
9749** </pre></blockquote>)^
9750**
9751** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
9752** routines return SQLITE_OK and set *P to point to the first or next value
9753** on the RHS of the IN constraint. ^If there are no more values on the
9754** right hand side of the IN constraint, then *P is set to NULL and these
9755** routines return [SQLITE_DONE]. ^The return value might be
9756** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
9757**
9758** The *ppOut values returned by these routines are only valid until the
9759** next call to either of these routines or until the end of the xFilter
9760** method from which these routines were called. If the virtual table
9761** implementation needs to retain the *ppOut values for longer, it must make
9762** copies. The *ppOut values are [protected sqlite3_value|protected].
9763*/
9764SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
9765SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
9766
9767/*
9768** CAPI3REF: Constraint values in xBestIndex()
9769** METHOD: sqlite3_index_info
9770**
9771** This API may only be used from within the [xBestIndex|xBestIndex method]
9772** of a [virtual table] implementation. The result of calling this interface
9773** from outside of an xBestIndex method are undefined and probably harmful.
9774**
9775** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
9776** the [xBestIndex] method of a [virtual table] implementation, with P being
9777** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
9778** J being a 0-based index into P->aConstraint[], then this routine
9779** attempts to set *V to the value of the right-hand operand of
9780** that constraint if the right-hand operand is known. ^If the
9781** right-hand operand is not known, then *V is set to a NULL pointer.
9782** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
9783** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
9784** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
9785** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
9786** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if
9787** something goes wrong.
9788**
9789** The sqlite3_vtab_rhs_value() interface is usually only successful if
9790** the right-hand operand of a constraint is a literal value in the original
9791** SQL statement. If the right-hand operand is an expression or a reference
9792** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
9793** will probably return [SQLITE_NOTFOUND].
9794**
9795** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
9796** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
9797** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
9798**
9799** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
9800** and remains valid for the duration of the xBestIndex method call.
9801** ^When xBestIndex returns, the sqlite3_value object returned by
9802** sqlite3_vtab_rhs_value() is automatically deallocated.
9803**
9804** The "_rhs_" in the name of this routine is an abbreviation for
9805** "Right-Hand Side".
9806*/
9807SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
9808
9809/*
9810** CAPI3REF: Conflict resolution modes
9811** KEYWORDS: {conflict resolution mode}
9812**
9813** These constants are returned by [sqlite3_vtab_on_conflict()] to
9814** inform a [virtual table] implementation what the [ON CONFLICT] mode
9815** is for the SQL statement being evaluated.
9816**
9817** Note that the [SQLITE_IGNORE] constant is also used as a potential
9818** return value from the [sqlite3_set_authorizer()] callback and that
9819** [SQLITE_ABORT] is also a [result code].
9820*/
9821#define SQLITE_ROLLBACK 1
9822/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
9823#define SQLITE_FAIL 3
9824/* #define SQLITE_ABORT 4 // Also an error code */
9825#define SQLITE_REPLACE 5
9826
9827/*
9828** CAPI3REF: Prepared Statement Scan Status Opcodes
9829** KEYWORDS: {scanstatus options}
9830**
9831** The following constants can be used for the T parameter to the
9832** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
9833** different metric for sqlite3_stmt_scanstatus() to return.
9834**
9835** When the value returned to V is a string, space to hold that string is
9836** managed by the prepared statement S and will be automatically freed when
9837** S is finalized.
9838**
9839** <dl>
9840** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
9841** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
9842** set to the total number of times that the X-th loop has run.</dd>
9843**
9844** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
9845** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
9846** to the total number of rows examined by all iterations of the X-th loop.</dd>
9847**
9848** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
9849** <dd>^The "double" variable pointed to by the V parameter will be set to the
9850** query planner's estimate for the average number of rows output from each
9851** iteration of the X-th loop. If the query planner's estimates was accurate,
9852** then this value will approximate the quotient NVISIT/NLOOP and the
9853** product of this value for all prior loops with the same SELECTID will
9854** be the NLOOP value for the current loop.
9855**
9856** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
9857** <dd>^The "const char *" variable pointed to by the V parameter will be set
9858** to a zero-terminated UTF-8 string containing the name of the index or table
9859** used for the X-th loop.
9860**
9861** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
9862** <dd>^The "const char *" variable pointed to by the V parameter will be set
9863** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
9864** description for the X-th loop.
9865**
9866** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
9867** <dd>^The "int" variable pointed to by the V parameter will be set to the
9868** "select-id" for the X-th loop. The select-id identifies which query or
9869** subquery the loop is part of. The main query has a select-id of zero.
9870** The select-id is the same value as is output in the first column
9871** of an [EXPLAIN QUERY PLAN] query.
9872** </dl>
9873*/
9874#define SQLITE_SCANSTAT_NLOOP 0
9875#define SQLITE_SCANSTAT_NVISIT 1
9876#define SQLITE_SCANSTAT_EST 2
9877#define SQLITE_SCANSTAT_NAME 3
9878#define SQLITE_SCANSTAT_EXPLAIN 4
9879#define SQLITE_SCANSTAT_SELECTID 5
9880
9881/*
9882** CAPI3REF: Prepared Statement Scan Status
9883** METHOD: sqlite3_stmt
9884**
9885** This interface returns information about the predicted and measured
9886** performance for pStmt. Advanced applications can use this
9887** interface to compare the predicted and the measured performance and
9888** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
9889**
9890** Since this interface is expected to be rarely used, it is only
9891** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
9892** compile-time option.
9893**
9894** The "iScanStatusOp" parameter determines which status information to return.
9895** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
9896** of this interface is undefined.
9897** ^The requested measurement is written into a variable pointed to by
9898** the "pOut" parameter.
9899** Parameter "idx" identifies the specific loop to retrieve statistics for.
9900** Loops are numbered starting from zero. ^If idx is out of range - less than
9901** zero or greater than or equal to the total number of loops used to implement
9902** the statement - a non-zero value is returned and the variable that pOut
9903** points to is unchanged.
9904**
9905** ^Statistics might not be available for all loops in all statements. ^In cases
9906** where there exist loops with no available statistics, this function behaves
9907** as if the loop did not exist - it returns non-zero and leave the variable
9908** that pOut points to unchanged.
9909**
9910** See also: [sqlite3_stmt_scanstatus_reset()]
9911*/
9912SQLITE_API int sqlite3_stmt_scanstatus(
9913 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
9914 int idx, /* Index of loop to report on */
9915 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
9916 void *pOut /* Result written here */
9917);
9918
9919/*
9920** CAPI3REF: Zero Scan-Status Counters
9921** METHOD: sqlite3_stmt
9922**
9923** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
9924**
9925** This API is only available if the library is built with pre-processor
9926** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
9927*/
9928SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
9929
9930/*
9931** CAPI3REF: Flush caches to disk mid-transaction
9932** METHOD: sqlite3
9933**
9934** ^If a write-transaction is open on [database connection] D when the
9935** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
9936** pages in the pager-cache that are not currently in use are written out
9937** to disk. A dirty page may be in use if a database cursor created by an
9938** active SQL statement is reading from it, or if it is page 1 of a database
9939** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
9940** interface flushes caches for all schemas - "main", "temp", and
9941** any [attached] databases.
9942**
9943** ^If this function needs to obtain extra database locks before dirty pages
9944** can be flushed to disk, it does so. ^If those locks cannot be obtained
9945** immediately and there is a busy-handler callback configured, it is invoked
9946** in the usual manner. ^If the required lock still cannot be obtained, then
9947** the database is skipped and an attempt made to flush any dirty pages
9948** belonging to the next (if any) database. ^If any databases are skipped
9949** because locks cannot be obtained, but no other error occurs, this
9950** function returns SQLITE_BUSY.
9951**
9952** ^If any other error occurs while flushing dirty pages to disk (for
9953** example an IO error or out-of-memory condition), then processing is
9954** abandoned and an SQLite [error code] is returned to the caller immediately.
9955**
9956** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
9957**
9958** ^This function does not set the database handle error code or message
9959** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
9960*/
9961SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
9962
9963/*
9964** CAPI3REF: The pre-update hook.
9965** METHOD: sqlite3
9966**
9967** ^These interfaces are only available if SQLite is compiled using the
9968** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
9969**
9970** ^The [sqlite3_preupdate_hook()] interface registers a callback function
9971** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
9972** on a database table.
9973** ^At most one preupdate hook may be registered at a time on a single
9974** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
9975** the previous setting.
9976** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
9977** with a NULL pointer as the second parameter.
9978** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
9979** the first parameter to callbacks.
9980**
9981** ^The preupdate hook only fires for changes to real database tables; the
9982** preupdate hook is not invoked for changes to [virtual tables] or to
9983** system tables like sqlite_sequence or sqlite_stat1.
9984**
9985** ^The second parameter to the preupdate callback is a pointer to
9986** the [database connection] that registered the preupdate hook.
9987** ^The third parameter to the preupdate callback is one of the constants
9988** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
9989** kind of update operation that is about to occur.
9990** ^(The fourth parameter to the preupdate callback is the name of the
9991** database within the database connection that is being modified. This
9992** will be "main" for the main database or "temp" for TEMP tables or
9993** the name given after the AS keyword in the [ATTACH] statement for attached
9994** databases.)^
9995** ^The fifth parameter to the preupdate callback is the name of the
9996** table that is being modified.
9997**
9998** For an UPDATE or DELETE operation on a [rowid table], the sixth
9999** parameter passed to the preupdate callback is the initial [rowid] of the
10000** row being modified or deleted. For an INSERT operation on a rowid table,
10001** or any operation on a WITHOUT ROWID table, the value of the sixth
10002** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10003** seventh parameter is the final rowid value of the row being inserted
10004** or updated. The value of the seventh parameter passed to the callback
10005** function is not defined for operations on WITHOUT ROWID tables, or for
10006** DELETE operations on rowid tables.
10007**
10008** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10009** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10010** provide additional information about a preupdate event. These routines
10011** may only be called from within a preupdate callback. Invoking any of
10012** these routines from outside of a preupdate callback or with a
10013** [database connection] pointer that is different from the one supplied
10014** to the preupdate callback results in undefined and probably undesirable
10015** behavior.
10016**
10017** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10018** in the row that is being inserted, updated, or deleted.
10019**
10020** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10021** a [protected sqlite3_value] that contains the value of the Nth column of
10022** the table row before it is updated. The N parameter must be between 0
10023** and one less than the number of columns or the behavior will be
10024** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10025** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10026** behavior is undefined. The [sqlite3_value] that P points to
10027** will be destroyed when the preupdate callback returns.
10028**
10029** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10030** a [protected sqlite3_value] that contains the value of the Nth column of
10031** the table row after it is updated. The N parameter must be between 0
10032** and one less than the number of columns or the behavior will be
10033** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10034** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10035** behavior is undefined. The [sqlite3_value] that P points to
10036** will be destroyed when the preupdate callback returns.
10037**
10038** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10039** callback was invoked as a result of a direct insert, update, or delete
10040** operation; or 1 for inserts, updates, or deletes invoked by top-level
10041** triggers; or 2 for changes resulting from triggers called by top-level
10042** triggers; and so forth.
10043**
10044** When the [sqlite3_blob_write()] API is used to update a blob column,
10045** the pre-update hook is invoked with SQLITE_DELETE. This is because the
10046** in this case the new values are not available. In this case, when a
10047** callback made with op==SQLITE_DELETE is actuall a write using the
10048** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10049** the index of the column being written. In other cases, where the
10050** pre-update hook is being invoked for some other reason, including a
10051** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10052**
10053** See also: [sqlite3_update_hook()]
10054*/
10055#if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10056SQLITE_API void *sqlite3_preupdate_hook(
10057 sqlite3 *db,
10058 void(*xPreUpdate)(
10059 void *pCtx, /* Copy of third arg to preupdate_hook() */
10060 sqlite3 *db, /* Database handle */
10061 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10062 char const *zDb, /* Database name */
10063 char const *zName, /* Table name */
10064 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10065 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10066 ),
10067 void*
10068);
10069SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10070SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10071SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10072SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10073SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10074#endif
10075
10076/*
10077** CAPI3REF: Low-level system error code
10078** METHOD: sqlite3
10079**
10080** ^Attempt to return the underlying operating system error code or error
10081** number that caused the most recent I/O error or failure to open a file.
10082** The return value is OS-dependent. For example, on unix systems, after
10083** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10084** called to get back the underlying "errno" that caused the problem, such
10085** as ENOSPC, EAUTH, EISDIR, and so forth.
10086*/
10087SQLITE_API int sqlite3_system_errno(sqlite3*);
10088
10089/*
10090** CAPI3REF: Database Snapshot
10091** KEYWORDS: {snapshot} {sqlite3_snapshot}
10092**
10093** An instance of the snapshot object records the state of a [WAL mode]
10094** database for some specific point in history.
10095**
10096** In [WAL mode], multiple [database connections] that are open on the
10097** same database file can each be reading a different historical version
10098** of the database file. When a [database connection] begins a read
10099** transaction, that connection sees an unchanging copy of the database
10100** as it existed for the point in time when the transaction first started.
10101** Subsequent changes to the database from other connections are not seen
10102** by the reader until a new read transaction is started.
10103**
10104** The sqlite3_snapshot object records state information about an historical
10105** version of the database file so that it is possible to later open a new read
10106** transaction that sees that historical version of the database rather than
10107** the most recent version.
10108*/
10109typedef struct sqlite3_snapshot {
10110 unsigned char hidden[48];
10111} sqlite3_snapshot;
10112
10113/*
10114** CAPI3REF: Record A Database Snapshot
10115** CONSTRUCTOR: sqlite3_snapshot
10116**
10117** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10118** new [sqlite3_snapshot] object that records the current state of
10119** schema S in database connection D. ^On success, the
10120** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10121** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10122** If there is not already a read-transaction open on schema S when
10123** this function is called, one is opened automatically.
10124**
10125** The following must be true for this function to succeed. If any of
10126** the following statements are false when sqlite3_snapshot_get() is
10127** called, SQLITE_ERROR is returned. The final value of *P is undefined
10128** in this case.
10129**
10130** <ul>
10131** <li> The database handle must not be in [autocommit mode].
10132**
10133** <li> Schema S of [database connection] D must be a [WAL mode] database.
10134**
10135** <li> There must not be a write transaction open on schema S of database
10136** connection D.
10137**
10138** <li> One or more transactions must have been written to the current wal
10139** file since it was created on disk (by any connection). This means
10140** that a snapshot cannot be taken on a wal mode database with no wal
10141** file immediately after it is first opened. At least one transaction
10142** must be written to it first.
10143** </ul>
10144**
10145** This function may also return SQLITE_NOMEM. If it is called with the
10146** database handle in autocommit mode but fails for some other reason,
10147** whether or not a read transaction is opened on schema S is undefined.
10148**
10149** The [sqlite3_snapshot] object returned from a successful call to
10150** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10151** to avoid a memory leak.
10152**
10153** The [sqlite3_snapshot_get()] interface is only available when the
10154** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10155*/
10156SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
10157 sqlite3 *db,
10158 const char *zSchema,
10159 sqlite3_snapshot **ppSnapshot
10160);
10161
10162/*
10163** CAPI3REF: Start a read transaction on an historical snapshot
10164** METHOD: sqlite3_snapshot
10165**
10166** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10167** transaction or upgrades an existing one for schema S of
10168** [database connection] D such that the read transaction refers to
10169** historical [snapshot] P, rather than the most recent change to the
10170** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10171** on success or an appropriate [error code] if it fails.
10172**
10173** ^In order to succeed, the database connection must not be in
10174** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10175** is already a read transaction open on schema S, then the database handle
10176** must have no active statements (SELECT statements that have been passed
10177** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10178** SQLITE_ERROR is returned if either of these conditions is violated, or
10179** if schema S does not exist, or if the snapshot object is invalid.
10180**
10181** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10182** snapshot has been overwritten by a [checkpoint]. In this case
10183** SQLITE_ERROR_SNAPSHOT is returned.
10184**
10185** If there is already a read transaction open when this function is
10186** invoked, then the same read transaction remains open (on the same
10187** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10188** is returned. If another error code - for example SQLITE_PROTOCOL or an
10189** SQLITE_IOERR error code - is returned, then the final state of the
10190** read transaction is undefined. If SQLITE_OK is returned, then the
10191** read transaction is now open on database snapshot P.
10192**
10193** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10194** database connection D does not know that the database file for
10195** schema S is in [WAL mode]. A database connection might not know
10196** that the database file is in [WAL mode] if there has been no prior
10197** I/O on that database connection, or if the database entered [WAL mode]
10198** after the most recent I/O on the database connection.)^
10199** (Hint: Run "[PRAGMA application_id]" against a newly opened
10200** database connection in order to make it ready to use snapshots.)
10201**
10202** The [sqlite3_snapshot_open()] interface is only available when the
10203** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10204*/
10205SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
10206 sqlite3 *db,
10207 const char *zSchema,
10208 sqlite3_snapshot *pSnapshot
10209);
10210
10211/*
10212** CAPI3REF: Destroy a snapshot
10213** DESTRUCTOR: sqlite3_snapshot
10214**
10215** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10216** The application must eventually free every [sqlite3_snapshot] object
10217** using this routine to avoid a memory leak.
10218**
10219** The [sqlite3_snapshot_free()] interface is only available when the
10220** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10221*/
10222SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
10223
10224/*
10225** CAPI3REF: Compare the ages of two snapshot handles.
10226** METHOD: sqlite3_snapshot
10227**
10228** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10229** of two valid snapshot handles.
10230**
10231** If the two snapshot handles are not associated with the same database
10232** file, the result of the comparison is undefined.
10233**
10234** Additionally, the result of the comparison is only valid if both of the
10235** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10236** last time the wal file was deleted. The wal file is deleted when the
10237** database is changed back to rollback mode or when the number of database
10238** clients drops to zero. If either snapshot handle was obtained before the
10239** wal file was last deleted, the value returned by this function
10240** is undefined.
10241**
10242** Otherwise, this API returns a negative value if P1 refers to an older
10243** snapshot than P2, zero if the two handles refer to the same database
10244** snapshot, and a positive value if P1 is a newer snapshot than P2.
10245**
10246** This interface is only available if SQLite is compiled with the
10247** [SQLITE_ENABLE_SNAPSHOT] option.
10248*/
10249SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
10250 sqlite3_snapshot *p1,
10251 sqlite3_snapshot *p2
10252);
10253
10254/*
10255** CAPI3REF: Recover snapshots from a wal file
10256** METHOD: sqlite3_snapshot
10257**
10258** If a [WAL file] remains on disk after all database connections close
10259** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10260** or because the last process to have the database opened exited without
10261** calling [sqlite3_close()]) and a new connection is subsequently opened
10262** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10263** will only be able to open the last transaction added to the WAL file
10264** even though the WAL file contains other valid transactions.
10265**
10266** This function attempts to scan the WAL file associated with database zDb
10267** of database handle db and make all valid snapshots available to
10268** sqlite3_snapshot_open(). It is an error if there is already a read
10269** transaction open on the database, or if the database is not a WAL mode
10270** database.
10271**
10272** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
10273**
10274** This interface is only available if SQLite is compiled with the
10275** [SQLITE_ENABLE_SNAPSHOT] option.
10276*/
10277SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
10278
10279/*
10280** CAPI3REF: Serialize a database
10281**
10282** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
10283** that is a serialization of the S database on [database connection] D.
10284** If P is not a NULL pointer, then the size of the database in bytes
10285** is written into *P.
10286**
10287** For an ordinary on-disk database file, the serialization is just a
10288** copy of the disk file. For an in-memory database or a "TEMP" database,
10289** the serialization is the same sequence of bytes which would be written
10290** to disk if that database where backed up to disk.
10291**
10292** The usual case is that sqlite3_serialize() copies the serialization of
10293** the database into memory obtained from [sqlite3_malloc64()] and returns
10294** a pointer to that memory. The caller is responsible for freeing the
10295** returned value to avoid a memory leak. However, if the F argument
10296** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
10297** are made, and the sqlite3_serialize() function will return a pointer
10298** to the contiguous memory representation of the database that SQLite
10299** is currently using for that database, or NULL if the no such contiguous
10300** memory representation of the database exists. A contiguous memory
10301** representation of the database will usually only exist if there has
10302** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
10303** values of D and S.
10304** The size of the database is written into *P even if the
10305** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
10306** of the database exists.
10307**
10308** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
10309** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
10310** allocation error occurs.
10311**
10312** This interface is omitted if SQLite is compiled with the
10313** [SQLITE_OMIT_DESERIALIZE] option.
10314*/
10315SQLITE_API unsigned char *sqlite3_serialize(
10316 sqlite3 *db, /* The database connection */
10317 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
10318 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
10319 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
10320);
10321
10322/*
10323** CAPI3REF: Flags for sqlite3_serialize
10324**
10325** Zero or more of the following constants can be OR-ed together for
10326** the F argument to [sqlite3_serialize(D,S,P,F)].
10327**
10328** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
10329** a pointer to contiguous in-memory database that it is currently using,
10330** without making a copy of the database. If SQLite is not currently using
10331** a contiguous in-memory database, then this option causes
10332** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
10333** using a contiguous in-memory database if it has been initialized by a
10334** prior call to [sqlite3_deserialize()].
10335*/
10336#define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
10337
10338/*
10339** CAPI3REF: Deserialize a database
10340**
10341** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
10342** [database connection] D to disconnect from database S and then
10343** reopen S as an in-memory database based on the serialization contained
10344** in P. The serialized database P is N bytes in size. M is the size of
10345** the buffer P, which might be larger than N. If M is larger than N, and
10346** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10347** permitted to add content to the in-memory database as long as the total
10348** size does not exceed M bytes.
10349**
10350** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10351** invoke sqlite3_free() on the serialization buffer when the database
10352** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10353** SQLite will try to increase the buffer size using sqlite3_realloc64()
10354** if writes on the database cause it to grow larger than M bytes.
10355**
10356** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
10357** database is currently in a read transaction or is involved in a backup
10358** operation.
10359**
10360** It is not possible to deserialized into the TEMP database. If the
10361** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
10362** function returns SQLITE_ERROR.
10363**
10364** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
10365** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
10366** [sqlite3_free()] is invoked on argument P prior to returning.
10367**
10368** This interface is omitted if SQLite is compiled with the
10369** [SQLITE_OMIT_DESERIALIZE] option.
10370*/
10371SQLITE_API int sqlite3_deserialize(
10372 sqlite3 *db, /* The database connection */
10373 const char *zSchema, /* Which DB to reopen with the deserialization */
10374 unsigned char *pData, /* The serialized database content */
10375 sqlite3_int64 szDb, /* Number bytes in the deserialization */
10376 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
10377 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
10378);
10379
10380/*
10381** CAPI3REF: Flags for sqlite3_deserialize()
10382**
10383** The following are allowed values for 6th argument (the F argument) to
10384** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
10385**
10386** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
10387** in the P argument is held in memory obtained from [sqlite3_malloc64()]
10388** and that SQLite should take ownership of this memory and automatically
10389** free it when it has finished using it. Without this flag, the caller
10390** is responsible for freeing any dynamically allocated memory.
10391**
10392** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
10393** grow the size of the database using calls to [sqlite3_realloc64()]. This
10394** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
10395** Without this flag, the deserialized database cannot increase in size beyond
10396** the number of bytes specified by the M parameter.
10397**
10398** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
10399** should be treated as read-only.
10400*/
10401#define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
10402#define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
10403#define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
10404
10405/*
10406** Undo the hack that converts floating point types to integer for
10407** builds on processors without floating point support.
10408*/
10409#ifdef SQLITE_OMIT_FLOATING_POINT
10410# undef double
10411#endif
10412
10413#ifdef __cplusplus
10414} /* End of the 'extern "C"' block */
10415#endif
10416#endif /* SQLITE3_H */
10417
10418/******** Begin file sqlite3rtree.h *********/
10419/*
10420** 2010 August 30
10421**
10422** The author disclaims copyright to this source code. In place of
10423** a legal notice, here is a blessing:
10424**
10425** May you do good and not evil.
10426** May you find forgiveness for yourself and forgive others.
10427** May you share freely, never taking more than you give.
10428**
10429*************************************************************************
10430*/
10431
10432#ifndef _SQLITE3RTREE_H_
10433#define _SQLITE3RTREE_H_
10434
10435
10436#ifdef __cplusplus
10437extern "C" {
10438#endif
10439
10440typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
10441typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
10442
10443/* The double-precision datatype used by RTree depends on the
10444** SQLITE_RTREE_INT_ONLY compile-time option.
10445*/
10446#ifdef SQLITE_RTREE_INT_ONLY
10447 typedef sqlite3_int64 sqlite3_rtree_dbl;
10448#else
10449 typedef double sqlite3_rtree_dbl;
10450#endif
10451
10452/*
10453** Register a geometry callback named zGeom that can be used as part of an
10454** R-Tree geometry query as follows:
10455**
10456** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
10457*/
10458SQLITE_API int sqlite3_rtree_geometry_callback(
10459 sqlite3 *db,
10460 const char *zGeom,
10461 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
10462 void *pContext
10463);
10464
10465
10466/*
10467** A pointer to a structure of the following type is passed as the first
10468** argument to callbacks registered using rtree_geometry_callback().
10469*/
10470struct sqlite3_rtree_geometry {
10471 void *pContext; /* Copy of pContext passed to s_r_g_c() */
10472 int nParam; /* Size of array aParam[] */
10473 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
10474 void *pUser; /* Callback implementation user data */
10475 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
10476};
10477
10478/*
10479** Register a 2nd-generation geometry callback named zScore that can be
10480** used as part of an R-Tree geometry query as follows:
10481**
10482** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
10483*/
10484SQLITE_API int sqlite3_rtree_query_callback(
10485 sqlite3 *db,
10486 const char *zQueryFunc,
10487 int (*xQueryFunc)(sqlite3_rtree_query_info*),
10488 void *pContext,
10489 void (*xDestructor)(void*)
10490);
10491
10492
10493/*
10494** A pointer to a structure of the following type is passed as the
10495** argument to scored geometry callback registered using
10496** sqlite3_rtree_query_callback().
10497**
10498** Note that the first 5 fields of this structure are identical to
10499** sqlite3_rtree_geometry. This structure is a subclass of
10500** sqlite3_rtree_geometry.
10501*/
10502struct sqlite3_rtree_query_info {
10503 void *pContext; /* pContext from when function registered */
10504 int nParam; /* Number of function parameters */
10505 sqlite3_rtree_dbl *aParam; /* value of function parameters */
10506 void *pUser; /* callback can use this, if desired */
10507 void (*xDelUser)(void*); /* function to free pUser */
10508 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
10509 unsigned int *anQueue; /* Number of pending entries in the queue */
10510 int nCoord; /* Number of coordinates */
10511 int iLevel; /* Level of current node or entry */
10512 int mxLevel; /* The largest iLevel value in the tree */
10513 sqlite3_int64 iRowid; /* Rowid for current entry */
10514 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
10515 int eParentWithin; /* Visibility of parent node */
10516 int eWithin; /* OUT: Visibility */
10517 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
10518 /* The following fields are only available in 3.8.11 and later */
10519 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
10520};
10521
10522/*
10523** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
10524*/
10525#define NOT_WITHIN 0 /* Object completely outside of query region */
10526#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
10527#define FULLY_WITHIN 2 /* Object fully contained within query region */
10528
10529
10530#ifdef __cplusplus
10531} /* end of the 'extern "C"' block */
10532#endif
10533
10534#endif /* ifndef _SQLITE3RTREE_H_ */
10535
10536/******** End of sqlite3rtree.h *********/
10537/******** Begin file sqlite3session.h *********/
10538
10539#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
10540#define __SQLITESESSION_H_ 1
10541
10542/*
10543** Make sure we can call this stuff from C++.
10544*/
10545#ifdef __cplusplus
10546extern "C" {
10547#endif
10548
10549
10550/*
10551** CAPI3REF: Session Object Handle
10552**
10553** An instance of this object is a [session] that can be used to
10554** record changes to a database.
10555*/
10556typedef struct sqlite3_session sqlite3_session;
10557
10558/*
10559** CAPI3REF: Changeset Iterator Handle
10560**
10561** An instance of this object acts as a cursor for iterating
10562** over the elements of a [changeset] or [patchset].
10563*/
10564typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
10565
10566/*
10567** CAPI3REF: Create A New Session Object
10568** CONSTRUCTOR: sqlite3_session
10569**
10570** Create a new session object attached to database handle db. If successful,
10571** a pointer to the new object is written to *ppSession and SQLITE_OK is
10572** returned. If an error occurs, *ppSession is set to NULL and an SQLite
10573** error code (e.g. SQLITE_NOMEM) is returned.
10574**
10575** It is possible to create multiple session objects attached to a single
10576** database handle.
10577**
10578** Session objects created using this function should be deleted using the
10579** [sqlite3session_delete()] function before the database handle that they
10580** are attached to is itself closed. If the database handle is closed before
10581** the session object is deleted, then the results of calling any session
10582** module function, including [sqlite3session_delete()] on the session object
10583** are undefined.
10584**
10585** Because the session module uses the [sqlite3_preupdate_hook()] API, it
10586** is not possible for an application to register a pre-update hook on a
10587** database handle that has one or more session objects attached. Nor is
10588** it possible to create a session object attached to a database handle for
10589** which a pre-update hook is already defined. The results of attempting
10590** either of these things are undefined.
10591**
10592** The session object will be used to create changesets for tables in
10593** database zDb, where zDb is either "main", or "temp", or the name of an
10594** attached database. It is not an error if database zDb is not attached
10595** to the database when the session object is created.
10596*/
10597SQLITE_API int sqlite3session_create(
10598 sqlite3 *db, /* Database handle */
10599 const char *zDb, /* Name of db (e.g. "main") */
10600 sqlite3_session **ppSession /* OUT: New session object */
10601);
10602
10603/*
10604** CAPI3REF: Delete A Session Object
10605** DESTRUCTOR: sqlite3_session
10606**
10607** Delete a session object previously allocated using
10608** [sqlite3session_create()]. Once a session object has been deleted, the
10609** results of attempting to use pSession with any other session module
10610** function are undefined.
10611**
10612** Session objects must be deleted before the database handle to which they
10613** are attached is closed. Refer to the documentation for
10614** [sqlite3session_create()] for details.
10615*/
10616SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
10617
10618/*
10619** CAPIREF: Conigure a Session Object
10620** METHOD: sqlite3_session
10621**
10622** This method is used to configure a session object after it has been
10623** created. At present the only valid value for the second parameter is
10624** [SQLITE_SESSION_OBJCONFIG_SIZE].
10625**
10626** Arguments for sqlite3session_object_config()
10627**
10628** The following values may passed as the the 4th parameter to
10629** sqlite3session_object_config().
10630**
10631** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
10632** This option is used to set, clear or query the flag that enables
10633** the [sqlite3session_changeset_size()] API. Because it imposes some
10634** computational overhead, this API is disabled by default. Argument
10635** pArg must point to a value of type (int). If the value is initially
10636** 0, then the sqlite3session_changeset_size() API is disabled. If it
10637** is greater than 0, then the same API is enabled. Or, if the initial
10638** value is less than zero, no change is made. In all cases the (int)
10639** variable is set to 1 if the sqlite3session_changeset_size() API is
10640** enabled following the current call, or 0 otherwise.
10641**
10642** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
10643** the first table has been attached to the session object.
10644*/
10645SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
10646
10647/*
10648*/
10649#define SQLITE_SESSION_OBJCONFIG_SIZE 1
10650
10651/*
10652** CAPI3REF: Enable Or Disable A Session Object
10653** METHOD: sqlite3_session
10654**
10655** Enable or disable the recording of changes by a session object. When
10656** enabled, a session object records changes made to the database. When
10657** disabled - it does not. A newly created session object is enabled.
10658** Refer to the documentation for [sqlite3session_changeset()] for further
10659** details regarding how enabling and disabling a session object affects
10660** the eventual changesets.
10661**
10662** Passing zero to this function disables the session. Passing a value
10663** greater than zero enables it. Passing a value less than zero is a
10664** no-op, and may be used to query the current state of the session.
10665**
10666** The return value indicates the final state of the session object: 0 if
10667** the session is disabled, or 1 if it is enabled.
10668*/
10669SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
10670
10671/*
10672** CAPI3REF: Set Or Clear the Indirect Change Flag
10673** METHOD: sqlite3_session
10674**
10675** Each change recorded by a session object is marked as either direct or
10676** indirect. A change is marked as indirect if either:
10677**
10678** <ul>
10679** <li> The session object "indirect" flag is set when the change is
10680** made, or
10681** <li> The change is made by an SQL trigger or foreign key action
10682** instead of directly as a result of a users SQL statement.
10683** </ul>
10684**
10685** If a single row is affected by more than one operation within a session,
10686** then the change is considered indirect if all operations meet the criteria
10687** for an indirect change above, or direct otherwise.
10688**
10689** This function is used to set, clear or query the session object indirect
10690** flag. If the second argument passed to this function is zero, then the
10691** indirect flag is cleared. If it is greater than zero, the indirect flag
10692** is set. Passing a value less than zero does not modify the current value
10693** of the indirect flag, and may be used to query the current state of the
10694** indirect flag for the specified session object.
10695**
10696** The return value indicates the final state of the indirect flag: 0 if
10697** it is clear, or 1 if it is set.
10698*/
10699SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
10700
10701/*
10702** CAPI3REF: Attach A Table To A Session Object
10703** METHOD: sqlite3_session
10704**
10705** If argument zTab is not NULL, then it is the name of a table to attach
10706** to the session object passed as the first argument. All subsequent changes
10707** made to the table while the session object is enabled will be recorded. See
10708** documentation for [sqlite3session_changeset()] for further details.
10709**
10710** Or, if argument zTab is NULL, then changes are recorded for all tables
10711** in the database. If additional tables are added to the database (by
10712** executing "CREATE TABLE" statements) after this call is made, changes for
10713** the new tables are also recorded.
10714**
10715** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
10716** defined as part of their CREATE TABLE statement. It does not matter if the
10717** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
10718** KEY may consist of a single column, or may be a composite key.
10719**
10720** It is not an error if the named table does not exist in the database. Nor
10721** is it an error if the named table does not have a PRIMARY KEY. However,
10722** no changes will be recorded in either of these scenarios.
10723**
10724** Changes are not recorded for individual rows that have NULL values stored
10725** in one or more of their PRIMARY KEY columns.
10726**
10727** SQLITE_OK is returned if the call completes without error. Or, if an error
10728** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
10729**
10730** <h3>Special sqlite_stat1 Handling</h3>
10731**
10732** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
10733** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
10734** <pre>
10735** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
10736** </pre>
10737**
10738** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
10739** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
10740** are recorded for rows for which (idx IS NULL) is true. However, for such
10741** rows a zero-length blob (SQL value X'') is stored in the changeset or
10742** patchset instead of a NULL value. This allows such changesets to be
10743** manipulated by legacy implementations of sqlite3changeset_invert(),
10744** concat() and similar.
10745**
10746** The sqlite3changeset_apply() function automatically converts the
10747** zero-length blob back to a NULL value when updating the sqlite_stat1
10748** table. However, if the application calls sqlite3changeset_new(),
10749** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
10750** iterator directly (including on a changeset iterator passed to a
10751** conflict-handler callback) then the X'' value is returned. The application
10752** must translate X'' to NULL itself if required.
10753**
10754** Legacy (older than 3.22.0) versions of the sessions module cannot capture
10755** changes made to the sqlite_stat1 table. Legacy versions of the
10756** sqlite3changeset_apply() function silently ignore any modifications to the
10757** sqlite_stat1 table that are part of a changeset or patchset.
10758*/
10759SQLITE_API int sqlite3session_attach(
10760 sqlite3_session *pSession, /* Session object */
10761 const char *zTab /* Table name */
10762);
10763
10764/*
10765** CAPI3REF: Set a table filter on a Session Object.
10766** METHOD: sqlite3_session
10767**
10768** The second argument (xFilter) is the "filter callback". For changes to rows
10769** in tables that are not attached to the Session object, the filter is called
10770** to determine whether changes to the table's rows should be tracked or not.
10771** If xFilter returns 0, changes are not tracked. Note that once a table is
10772** attached, xFilter will not be called again.
10773*/
10774SQLITE_API void sqlite3session_table_filter(
10775 sqlite3_session *pSession, /* Session object */
10776 int(*xFilter)(
10777 void *pCtx, /* Copy of third arg to _filter_table() */
10778 const char *zTab /* Table name */
10779 ),
10780 void *pCtx /* First argument passed to xFilter */
10781);
10782
10783/*
10784** CAPI3REF: Generate A Changeset From A Session Object
10785** METHOD: sqlite3_session
10786**
10787** Obtain a changeset containing changes to the tables attached to the
10788** session object passed as the first argument. If successful,
10789** set *ppChangeset to point to a buffer containing the changeset
10790** and *pnChangeset to the size of the changeset in bytes before returning
10791** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
10792** zero and return an SQLite error code.
10793**
10794** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
10795** each representing a change to a single row of an attached table. An INSERT
10796** change contains the values of each field of a new database row. A DELETE
10797** contains the original values of each field of a deleted database row. An
10798** UPDATE change contains the original values of each field of an updated
10799** database row along with the updated values for each updated non-primary-key
10800** column. It is not possible for an UPDATE change to represent a change that
10801** modifies the values of primary key columns. If such a change is made, it
10802** is represented in a changeset as a DELETE followed by an INSERT.
10803**
10804** Changes are not recorded for rows that have NULL values stored in one or
10805** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
10806** no corresponding change is present in the changesets returned by this
10807** function. If an existing row with one or more NULL values stored in
10808** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
10809** only an INSERT is appears in the changeset. Similarly, if an existing row
10810** with non-NULL PRIMARY KEY values is updated so that one or more of its
10811** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
10812** DELETE change only.
10813**
10814** The contents of a changeset may be traversed using an iterator created
10815** using the [sqlite3changeset_start()] API. A changeset may be applied to
10816** a database with a compatible schema using the [sqlite3changeset_apply()]
10817** API.
10818**
10819** Within a changeset generated by this function, all changes related to a
10820** single table are grouped together. In other words, when iterating through
10821** a changeset or when applying a changeset to a database, all changes related
10822** to a single table are processed before moving on to the next table. Tables
10823** are sorted in the same order in which they were attached (or auto-attached)
10824** to the sqlite3_session object. The order in which the changes related to
10825** a single table are stored is undefined.
10826**
10827** Following a successful call to this function, it is the responsibility of
10828** the caller to eventually free the buffer that *ppChangeset points to using
10829** [sqlite3_free()].
10830**
10831** <h3>Changeset Generation</h3>
10832**
10833** Once a table has been attached to a session object, the session object
10834** records the primary key values of all new rows inserted into the table.
10835** It also records the original primary key and other column values of any
10836** deleted or updated rows. For each unique primary key value, data is only
10837** recorded once - the first time a row with said primary key is inserted,
10838** updated or deleted in the lifetime of the session.
10839**
10840** There is one exception to the previous paragraph: when a row is inserted,
10841** updated or deleted, if one or more of its primary key columns contain a
10842** NULL value, no record of the change is made.
10843**
10844** The session object therefore accumulates two types of records - those
10845** that consist of primary key values only (created when the user inserts
10846** a new record) and those that consist of the primary key values and the
10847** original values of other table columns (created when the users deletes
10848** or updates a record).
10849**
10850** When this function is called, the requested changeset is created using
10851** both the accumulated records and the current contents of the database
10852** file. Specifically:
10853**
10854** <ul>
10855** <li> For each record generated by an insert, the database is queried
10856** for a row with a matching primary key. If one is found, an INSERT
10857** change is added to the changeset. If no such row is found, no change
10858** is added to the changeset.
10859**
10860** <li> For each record generated by an update or delete, the database is
10861** queried for a row with a matching primary key. If such a row is
10862** found and one or more of the non-primary key fields have been
10863** modified from their original values, an UPDATE change is added to
10864** the changeset. Or, if no such row is found in the table, a DELETE
10865** change is added to the changeset. If there is a row with a matching
10866** primary key in the database, but all fields contain their original
10867** values, no change is added to the changeset.
10868** </ul>
10869**
10870** This means, amongst other things, that if a row is inserted and then later
10871** deleted while a session object is active, neither the insert nor the delete
10872** will be present in the changeset. Or if a row is deleted and then later a
10873** row with the same primary key values inserted while a session object is
10874** active, the resulting changeset will contain an UPDATE change instead of
10875** a DELETE and an INSERT.
10876**
10877** When a session object is disabled (see the [sqlite3session_enable()] API),
10878** it does not accumulate records when rows are inserted, updated or deleted.
10879** This may appear to have some counter-intuitive effects if a single row
10880** is written to more than once during a session. For example, if a row
10881** is inserted while a session object is enabled, then later deleted while
10882** the same session object is disabled, no INSERT record will appear in the
10883** changeset, even though the delete took place while the session was disabled.
10884** Or, if one field of a row is updated while a session is disabled, and
10885** another field of the same row is updated while the session is enabled, the
10886** resulting changeset will contain an UPDATE change that updates both fields.
10887*/
10888SQLITE_API int sqlite3session_changeset(
10889 sqlite3_session *pSession, /* Session object */
10890 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
10891 void **ppChangeset /* OUT: Buffer containing changeset */
10892);
10893
10894/*
10895** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
10896** METHOD: sqlite3_session
10897**
10898** By default, this function always returns 0. For it to return
10899** a useful result, the sqlite3_session object must have been configured
10900** to enable this API using sqlite3session_object_config() with the
10901** SQLITE_SESSION_OBJCONFIG_SIZE verb.
10902**
10903** When enabled, this function returns an upper limit, in bytes, for the size
10904** of the changeset that might be produced if sqlite3session_changeset() were
10905** called. The final changeset size might be equal to or smaller than the
10906** size in bytes returned by this function.
10907*/
10908SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
10909
10910/*
10911** CAPI3REF: Load The Difference Between Tables Into A Session
10912** METHOD: sqlite3_session
10913**
10914** If it is not already attached to the session object passed as the first
10915** argument, this function attaches table zTbl in the same manner as the
10916** [sqlite3session_attach()] function. If zTbl does not exist, or if it
10917** does not have a primary key, this function is a no-op (but does not return
10918** an error).
10919**
10920** Argument zFromDb must be the name of a database ("main", "temp" etc.)
10921** attached to the same database handle as the session object that contains
10922** a table compatible with the table attached to the session by this function.
10923** A table is considered compatible if it:
10924**
10925** <ul>
10926** <li> Has the same name,
10927** <li> Has the same set of columns declared in the same order, and
10928** <li> Has the same PRIMARY KEY definition.
10929** </ul>
10930**
10931** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
10932** are compatible but do not have any PRIMARY KEY columns, it is not an error
10933** but no changes are added to the session object. As with other session
10934** APIs, tables without PRIMARY KEYs are simply ignored.
10935**
10936** This function adds a set of changes to the session object that could be
10937** used to update the table in database zFrom (call this the "from-table")
10938** so that its content is the same as the table attached to the session
10939** object (call this the "to-table"). Specifically:
10940**
10941** <ul>
10942** <li> For each row (primary key) that exists in the to-table but not in
10943** the from-table, an INSERT record is added to the session object.
10944**
10945** <li> For each row (primary key) that exists in the to-table but not in
10946** the from-table, a DELETE record is added to the session object.
10947**
10948** <li> For each row (primary key) that exists in both tables, but features
10949** different non-PK values in each, an UPDATE record is added to the
10950** session.
10951** </ul>
10952**
10953** To clarify, if this function is called and then a changeset constructed
10954** using [sqlite3session_changeset()], then after applying that changeset to
10955** database zFrom the contents of the two compatible tables would be
10956** identical.
10957**
10958** It an error if database zFrom does not exist or does not contain the
10959** required compatible table.
10960**
10961** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
10962** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
10963** may be set to point to a buffer containing an English language error
10964** message. It is the responsibility of the caller to free this buffer using
10965** sqlite3_free().
10966*/
10967SQLITE_API int sqlite3session_diff(
10968 sqlite3_session *pSession,
10969 const char *zFromDb,
10970 const char *zTbl,
10971 char **pzErrMsg
10972);
10973
10974
10975/*
10976** CAPI3REF: Generate A Patchset From A Session Object
10977** METHOD: sqlite3_session
10978**
10979** The differences between a patchset and a changeset are that:
10980**
10981** <ul>
10982** <li> DELETE records consist of the primary key fields only. The
10983** original values of other fields are omitted.
10984** <li> The original values of any modified fields are omitted from
10985** UPDATE records.
10986** </ul>
10987**
10988** A patchset blob may be used with up to date versions of all
10989** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
10990** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
10991** attempting to use a patchset blob with old versions of the
10992** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
10993**
10994** Because the non-primary key "old.*" fields are omitted, no
10995** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
10996** is passed to the sqlite3changeset_apply() API. Other conflict types work
10997** in the same way as for changesets.
10998**
10999** Changes within a patchset are ordered in the same way as for changesets
11000** generated by the sqlite3session_changeset() function (i.e. all changes for
11001** a single table are grouped together, tables appear in the order in which
11002** they were attached to the session object).
11003*/
11004SQLITE_API int sqlite3session_patchset(
11005 sqlite3_session *pSession, /* Session object */
11006 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11007 void **ppPatchset /* OUT: Buffer containing patchset */
11008);
11009
11010/*
11011** CAPI3REF: Test if a changeset has recorded any changes.
11012**
11013** Return non-zero if no changes to attached tables have been recorded by
11014** the session object passed as the first argument. Otherwise, if one or
11015** more changes have been recorded, return zero.
11016**
11017** Even if this function returns zero, it is possible that calling
11018** [sqlite3session_changeset()] on the session handle may still return a
11019** changeset that contains no changes. This can happen when a row in
11020** an attached table is modified and then later on the original values
11021** are restored. However, if this function returns non-zero, then it is
11022** guaranteed that a call to sqlite3session_changeset() will return a
11023** changeset containing zero changes.
11024*/
11025SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11026
11027/*
11028** CAPI3REF: Query for the amount of heap memory used by a session object.
11029**
11030** This API returns the total amount of heap memory in bytes currently
11031** used by the session object passed as the only argument.
11032*/
11033SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11034
11035/*
11036** CAPI3REF: Create An Iterator To Traverse A Changeset
11037** CONSTRUCTOR: sqlite3_changeset_iter
11038**
11039** Create an iterator used to iterate through the contents of a changeset.
11040** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11041** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11042** SQLite error code is returned.
11043**
11044** The following functions can be used to advance and query a changeset
11045** iterator created by this function:
11046**
11047** <ul>
11048** <li> [sqlite3changeset_next()]
11049** <li> [sqlite3changeset_op()]
11050** <li> [sqlite3changeset_new()]
11051** <li> [sqlite3changeset_old()]
11052** </ul>
11053**
11054** It is the responsibility of the caller to eventually destroy the iterator
11055** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11056** changeset (pChangeset) must remain valid until after the iterator is
11057** destroyed.
11058**
11059** Assuming the changeset blob was created by one of the
11060** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11061** [sqlite3changeset_invert()] functions, all changes within the changeset
11062** that apply to a single table are grouped together. This means that when
11063** an application iterates through a changeset using an iterator created by
11064** this function, all changes that relate to a single table are visited
11065** consecutively. There is no chance that the iterator will visit a change
11066** the applies to table X, then one for table Y, and then later on visit
11067** another change for table X.
11068**
11069** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11070** may be modified by passing a combination of
11071** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11072**
11073** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11074** and therefore subject to change.
11075*/
11076SQLITE_API int sqlite3changeset_start(
11077 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11078 int nChangeset, /* Size of changeset blob in bytes */
11079 void *pChangeset /* Pointer to blob containing changeset */
11080);
11081SQLITE_API int sqlite3changeset_start_v2(
11082 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11083 int nChangeset, /* Size of changeset blob in bytes */
11084 void *pChangeset, /* Pointer to blob containing changeset */
11085 int flags /* SESSION_CHANGESETSTART_* flags */
11086);
11087
11088/*
11089** CAPI3REF: Flags for sqlite3changeset_start_v2
11090**
11091** The following flags may passed via the 4th parameter to
11092** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11093**
11094** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11095** Invert the changeset while iterating through it. This is equivalent to
11096** inverting a changeset using sqlite3changeset_invert() before applying it.
11097** It is an error to specify this flag with a patchset.
11098*/
11099#define SQLITE_CHANGESETSTART_INVERT 0x0002
11100
11101
11102/*
11103** CAPI3REF: Advance A Changeset Iterator
11104** METHOD: sqlite3_changeset_iter
11105**
11106** This function may only be used with iterators created by the function
11107** [sqlite3changeset_start()]. If it is called on an iterator passed to
11108** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11109** is returned and the call has no effect.
11110**
11111** Immediately after an iterator is created by sqlite3changeset_start(), it
11112** does not point to any change in the changeset. Assuming the changeset
11113** is not empty, the first call to this function advances the iterator to
11114** point to the first change in the changeset. Each subsequent call advances
11115** the iterator to point to the next change in the changeset (if any). If
11116** no error occurs and the iterator points to a valid change after a call
11117** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11118** Otherwise, if all changes in the changeset have already been visited,
11119** SQLITE_DONE is returned.
11120**
11121** If an error occurs, an SQLite error code is returned. Possible error
11122** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11123** SQLITE_NOMEM.
11124*/
11125SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11126
11127/*
11128** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11129** METHOD: sqlite3_changeset_iter
11130**
11131** The pIter argument passed to this function may either be an iterator
11132** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11133** created by [sqlite3changeset_start()]. In the latter case, the most recent
11134** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11135** is not the case, this function returns [SQLITE_MISUSE].
11136**
11137** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11138** outputs are set through these pointers:
11139**
11140** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11141** depending on the type of change that the iterator currently points to;
11142**
11143** *pnCol is set to the number of columns in the table affected by the change; and
11144**
11145** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11146** the name of the table affected by the current change. The buffer remains
11147** valid until either sqlite3changeset_next() is called on the iterator
11148** or until the conflict-handler function returns.
11149**
11150** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11151** is an indirect change, or false (0) otherwise. See the documentation for
11152** [sqlite3session_indirect()] for a description of direct and indirect
11153** changes.
11154**
11155** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11156** SQLite error code is returned. The values of the output variables may not
11157** be trusted in this case.
11158*/
11159SQLITE_API int sqlite3changeset_op(
11160 sqlite3_changeset_iter *pIter, /* Iterator object */
11161 const char **pzTab, /* OUT: Pointer to table name */
11162 int *pnCol, /* OUT: Number of columns in table */
11163 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11164 int *pbIndirect /* OUT: True for an 'indirect' change */
11165);
11166
11167/*
11168** CAPI3REF: Obtain The Primary Key Definition Of A Table
11169** METHOD: sqlite3_changeset_iter
11170**
11171** For each modified table, a changeset includes the following:
11172**
11173** <ul>
11174** <li> The number of columns in the table, and
11175** <li> Which of those columns make up the tables PRIMARY KEY.
11176** </ul>
11177**
11178** This function is used to find which columns comprise the PRIMARY KEY of
11179** the table modified by the change that iterator pIter currently points to.
11180** If successful, *pabPK is set to point to an array of nCol entries, where
11181** nCol is the number of columns in the table. Elements of *pabPK are set to
11182** 0x01 if the corresponding column is part of the tables primary key, or
11183** 0x00 if it is not.
11184**
11185** If argument pnCol is not NULL, then *pnCol is set to the number of columns
11186** in the table.
11187**
11188** If this function is called when the iterator does not point to a valid
11189** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
11190** SQLITE_OK is returned and the output variables populated as described
11191** above.
11192*/
11193SQLITE_API int sqlite3changeset_pk(
11194 sqlite3_changeset_iter *pIter, /* Iterator object */
11195 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
11196 int *pnCol /* OUT: Number of entries in output array */
11197);
11198
11199/*
11200** CAPI3REF: Obtain old.* Values From A Changeset Iterator
11201** METHOD: sqlite3_changeset_iter
11202**
11203** The pIter argument passed to this function may either be an iterator
11204** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11205** created by [sqlite3changeset_start()]. In the latter case, the most recent
11206** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11207** Furthermore, it may only be called if the type of change that the iterator
11208** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
11209** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11210**
11211** Argument iVal must be greater than or equal to 0, and less than the number
11212** of columns in the table affected by the current change. Otherwise,
11213** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11214**
11215** If successful, this function sets *ppValue to point to a protected
11216** sqlite3_value object containing the iVal'th value from the vector of
11217** original row values stored as part of the UPDATE or DELETE change and
11218** returns SQLITE_OK. The name of the function comes from the fact that this
11219** is similar to the "old.*" columns available to update or delete triggers.
11220**
11221** If some other error occurs (e.g. an OOM condition), an SQLite error code
11222** is returned and *ppValue is set to NULL.
11223*/
11224SQLITE_API int sqlite3changeset_old(
11225 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11226 int iVal, /* Column number */
11227 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
11228);
11229
11230/*
11231** CAPI3REF: Obtain new.* Values From A Changeset Iterator
11232** METHOD: sqlite3_changeset_iter
11233**
11234** The pIter argument passed to this function may either be an iterator
11235** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11236** created by [sqlite3changeset_start()]. In the latter case, the most recent
11237** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11238** Furthermore, it may only be called if the type of change that the iterator
11239** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
11240** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11241**
11242** Argument iVal must be greater than or equal to 0, and less than the number
11243** of columns in the table affected by the current change. Otherwise,
11244** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11245**
11246** If successful, this function sets *ppValue to point to a protected
11247** sqlite3_value object containing the iVal'th value from the vector of
11248** new row values stored as part of the UPDATE or INSERT change and
11249** returns SQLITE_OK. If the change is an UPDATE and does not include
11250** a new value for the requested column, *ppValue is set to NULL and
11251** SQLITE_OK returned. The name of the function comes from the fact that
11252** this is similar to the "new.*" columns available to update or delete
11253** triggers.
11254**
11255** If some other error occurs (e.g. an OOM condition), an SQLite error code
11256** is returned and *ppValue is set to NULL.
11257*/
11258SQLITE_API int sqlite3changeset_new(
11259 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11260 int iVal, /* Column number */
11261 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
11262);
11263
11264/*
11265** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
11266** METHOD: sqlite3_changeset_iter
11267**
11268** This function should only be used with iterator objects passed to a
11269** conflict-handler callback by [sqlite3changeset_apply()] with either
11270** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
11271** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
11272** is set to NULL.
11273**
11274** Argument iVal must be greater than or equal to 0, and less than the number
11275** of columns in the table affected by the current change. Otherwise,
11276** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11277**
11278** If successful, this function sets *ppValue to point to a protected
11279** sqlite3_value object containing the iVal'th value from the
11280** "conflicting row" associated with the current conflict-handler callback
11281** and returns SQLITE_OK.
11282**
11283** If some other error occurs (e.g. an OOM condition), an SQLite error code
11284** is returned and *ppValue is set to NULL.
11285*/
11286SQLITE_API int sqlite3changeset_conflict(
11287 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11288 int iVal, /* Column number */
11289 sqlite3_value **ppValue /* OUT: Value from conflicting row */
11290);
11291
11292/*
11293** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
11294** METHOD: sqlite3_changeset_iter
11295**
11296** This function may only be called with an iterator passed to an
11297** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
11298** it sets the output variable to the total number of known foreign key
11299** violations in the destination database and returns SQLITE_OK.
11300**
11301** In all other cases this function returns SQLITE_MISUSE.
11302*/
11303SQLITE_API int sqlite3changeset_fk_conflicts(
11304 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11305 int *pnOut /* OUT: Number of FK violations */
11306);
11307
11308
11309/*
11310** CAPI3REF: Finalize A Changeset Iterator
11311** METHOD: sqlite3_changeset_iter
11312**
11313** This function is used to finalize an iterator allocated with
11314** [sqlite3changeset_start()].
11315**
11316** This function should only be called on iterators created using the
11317** [sqlite3changeset_start()] function. If an application calls this
11318** function with an iterator passed to a conflict-handler by
11319** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
11320** call has no effect.
11321**
11322** If an error was encountered within a call to an sqlite3changeset_xxx()
11323** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
11324** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
11325** to that error is returned by this function. Otherwise, SQLITE_OK is
11326** returned. This is to allow the following pattern (pseudo-code):
11327**
11328** <pre>
11329** sqlite3changeset_start();
11330** while( SQLITE_ROW==sqlite3changeset_next() ){
11331** // Do something with change.
11332** }
11333** rc = sqlite3changeset_finalize();
11334** if( rc!=SQLITE_OK ){
11335** // An error has occurred
11336** }
11337** </pre>
11338*/
11339SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
11340
11341/*
11342** CAPI3REF: Invert A Changeset
11343**
11344** This function is used to "invert" a changeset object. Applying an inverted
11345** changeset to a database reverses the effects of applying the uninverted
11346** changeset. Specifically:
11347**
11348** <ul>
11349** <li> Each DELETE change is changed to an INSERT, and
11350** <li> Each INSERT change is changed to a DELETE, and
11351** <li> For each UPDATE change, the old.* and new.* values are exchanged.
11352** </ul>
11353**
11354** This function does not change the order in which changes appear within
11355** the changeset. It merely reverses the sense of each individual change.
11356**
11357** If successful, a pointer to a buffer containing the inverted changeset
11358** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
11359** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
11360** zeroed and an SQLite error code returned.
11361**
11362** It is the responsibility of the caller to eventually call sqlite3_free()
11363** on the *ppOut pointer to free the buffer allocation following a successful
11364** call to this function.
11365**
11366** WARNING/TODO: This function currently assumes that the input is a valid
11367** changeset. If it is not, the results are undefined.
11368*/
11369SQLITE_API int sqlite3changeset_invert(
11370 int nIn, const void *pIn, /* Input changeset */
11371 int *pnOut, void **ppOut /* OUT: Inverse of input */
11372);
11373
11374/*
11375** CAPI3REF: Concatenate Two Changeset Objects
11376**
11377** This function is used to concatenate two changesets, A and B, into a
11378** single changeset. The result is a changeset equivalent to applying
11379** changeset A followed by changeset B.
11380**
11381** This function combines the two input changesets using an
11382** sqlite3_changegroup object. Calling it produces similar results as the
11383** following code fragment:
11384**
11385** <pre>
11386** sqlite3_changegroup *pGrp;
11387** rc = sqlite3_changegroup_new(&pGrp);
11388** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
11389** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
11390** if( rc==SQLITE_OK ){
11391** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
11392** }else{
11393** *ppOut = 0;
11394** *pnOut = 0;
11395** }
11396** </pre>
11397**
11398** Refer to the sqlite3_changegroup documentation below for details.
11399*/
11400SQLITE_API int sqlite3changeset_concat(
11401 int nA, /* Number of bytes in buffer pA */
11402 void *pA, /* Pointer to buffer containing changeset A */
11403 int nB, /* Number of bytes in buffer pB */
11404 void *pB, /* Pointer to buffer containing changeset B */
11405 int *pnOut, /* OUT: Number of bytes in output changeset */
11406 void **ppOut /* OUT: Buffer containing output changeset */
11407);
11408
11409
11410/*
11411** CAPI3REF: Changegroup Handle
11412**
11413** A changegroup is an object used to combine two or more
11414** [changesets] or [patchsets]
11415*/
11416typedef struct sqlite3_changegroup sqlite3_changegroup;
11417
11418/*
11419** CAPI3REF: Create A New Changegroup Object
11420** CONSTRUCTOR: sqlite3_changegroup
11421**
11422** An sqlite3_changegroup object is used to combine two or more changesets
11423** (or patchsets) into a single changeset (or patchset). A single changegroup
11424** object may combine changesets or patchsets, but not both. The output is
11425** always in the same format as the input.
11426**
11427** If successful, this function returns SQLITE_OK and populates (*pp) with
11428** a pointer to a new sqlite3_changegroup object before returning. The caller
11429** should eventually free the returned object using a call to
11430** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
11431** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
11432**
11433** The usual usage pattern for an sqlite3_changegroup object is as follows:
11434**
11435** <ul>
11436** <li> It is created using a call to sqlite3changegroup_new().
11437**
11438** <li> Zero or more changesets (or patchsets) are added to the object
11439** by calling sqlite3changegroup_add().
11440**
11441** <li> The result of combining all input changesets together is obtained
11442** by the application via a call to sqlite3changegroup_output().
11443**
11444** <li> The object is deleted using a call to sqlite3changegroup_delete().
11445** </ul>
11446**
11447** Any number of calls to add() and output() may be made between the calls to
11448** new() and delete(), and in any order.
11449**
11450** As well as the regular sqlite3changegroup_add() and
11451** sqlite3changegroup_output() functions, also available are the streaming
11452** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
11453*/
11454SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
11455
11456/*
11457** CAPI3REF: Add A Changeset To A Changegroup
11458** METHOD: sqlite3_changegroup
11459**
11460** Add all changes within the changeset (or patchset) in buffer pData (size
11461** nData bytes) to the changegroup.
11462**
11463** If the buffer contains a patchset, then all prior calls to this function
11464** on the same changegroup object must also have specified patchsets. Or, if
11465** the buffer contains a changeset, so must have the earlier calls to this
11466** function. Otherwise, SQLITE_ERROR is returned and no changes are added
11467** to the changegroup.
11468**
11469** Rows within the changeset and changegroup are identified by the values in
11470** their PRIMARY KEY columns. A change in the changeset is considered to
11471** apply to the same row as a change already present in the changegroup if
11472** the two rows have the same primary key.
11473**
11474** Changes to rows that do not already appear in the changegroup are
11475** simply copied into it. Or, if both the new changeset and the changegroup
11476** contain changes that apply to a single row, the final contents of the
11477** changegroup depends on the type of each change, as follows:
11478**
11479** <table border=1 style="margin-left:8ex;margin-right:8ex">
11480** <tr><th style="white-space:pre">Existing Change </th>
11481** <th style="white-space:pre">New Change </th>
11482** <th>Output Change
11483** <tr><td>INSERT <td>INSERT <td>
11484** The new change is ignored. This case does not occur if the new
11485** changeset was recorded immediately after the changesets already
11486** added to the changegroup.
11487** <tr><td>INSERT <td>UPDATE <td>
11488** The INSERT change remains in the changegroup. The values in the
11489** INSERT change are modified as if the row was inserted by the
11490** existing change and then updated according to the new change.
11491** <tr><td>INSERT <td>DELETE <td>
11492** The existing INSERT is removed from the changegroup. The DELETE is
11493** not added.
11494** <tr><td>UPDATE <td>INSERT <td>
11495** The new change is ignored. This case does not occur if the new
11496** changeset was recorded immediately after the changesets already
11497** added to the changegroup.
11498** <tr><td>UPDATE <td>UPDATE <td>
11499** The existing UPDATE remains within the changegroup. It is amended
11500** so that the accompanying values are as if the row was updated once
11501** by the existing change and then again by the new change.
11502** <tr><td>UPDATE <td>DELETE <td>
11503** The existing UPDATE is replaced by the new DELETE within the
11504** changegroup.
11505** <tr><td>DELETE <td>INSERT <td>
11506** If one or more of the column values in the row inserted by the
11507** new change differ from those in the row deleted by the existing
11508** change, the existing DELETE is replaced by an UPDATE within the
11509** changegroup. Otherwise, if the inserted row is exactly the same
11510** as the deleted row, the existing DELETE is simply discarded.
11511** <tr><td>DELETE <td>UPDATE <td>
11512** The new change is ignored. This case does not occur if the new
11513** changeset was recorded immediately after the changesets already
11514** added to the changegroup.
11515** <tr><td>DELETE <td>DELETE <td>
11516** The new change is ignored. This case does not occur if the new
11517** changeset was recorded immediately after the changesets already
11518** added to the changegroup.
11519** </table>
11520**
11521** If the new changeset contains changes to a table that is already present
11522** in the changegroup, then the number of columns and the position of the
11523** primary key columns for the table must be consistent. If this is not the
11524** case, this function fails with SQLITE_SCHEMA. If the input changeset
11525** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
11526** returned. Or, if an out-of-memory condition occurs during processing, this
11527** function returns SQLITE_NOMEM. In all cases, if an error occurs the state
11528** of the final contents of the changegroup is undefined.
11529**
11530** If no error occurs, SQLITE_OK is returned.
11531*/
11532SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
11533
11534/*
11535** CAPI3REF: Obtain A Composite Changeset From A Changegroup
11536** METHOD: sqlite3_changegroup
11537**
11538** Obtain a buffer containing a changeset (or patchset) representing the
11539** current contents of the changegroup. If the inputs to the changegroup
11540** were themselves changesets, the output is a changeset. Or, if the
11541** inputs were patchsets, the output is also a patchset.
11542**
11543** As with the output of the sqlite3session_changeset() and
11544** sqlite3session_patchset() functions, all changes related to a single
11545** table are grouped together in the output of this function. Tables appear
11546** in the same order as for the very first changeset added to the changegroup.
11547** If the second or subsequent changesets added to the changegroup contain
11548** changes for tables that do not appear in the first changeset, they are
11549** appended onto the end of the output changeset, again in the order in
11550** which they are first encountered.
11551**
11552** If an error occurs, an SQLite error code is returned and the output
11553** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
11554** is returned and the output variables are set to the size of and a
11555** pointer to the output buffer, respectively. In this case it is the
11556** responsibility of the caller to eventually free the buffer using a
11557** call to sqlite3_free().
11558*/
11559SQLITE_API int sqlite3changegroup_output(
11560 sqlite3_changegroup*,
11561 int *pnData, /* OUT: Size of output buffer in bytes */
11562 void **ppData /* OUT: Pointer to output buffer */
11563);
11564
11565/*
11566** CAPI3REF: Delete A Changegroup Object
11567** DESTRUCTOR: sqlite3_changegroup
11568*/
11569SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
11570
11571/*
11572** CAPI3REF: Apply A Changeset To A Database
11573**
11574** Apply a changeset or patchset to a database. These functions attempt to
11575** update the "main" database attached to handle db with the changes found in
11576** the changeset passed via the second and third arguments.
11577**
11578** The fourth argument (xFilter) passed to these functions is the "filter
11579** callback". If it is not NULL, then for each table affected by at least one
11580** change in the changeset, the filter callback is invoked with
11581** the table name as the second argument, and a copy of the context pointer
11582** passed as the sixth argument as the first. If the "filter callback"
11583** returns zero, then no attempt is made to apply any changes to the table.
11584** Otherwise, if the return value is non-zero or the xFilter argument to
11585** is NULL, all changes related to the table are attempted.
11586**
11587** For each table that is not excluded by the filter callback, this function
11588** tests that the target database contains a compatible table. A table is
11589** considered compatible if all of the following are true:
11590**
11591** <ul>
11592** <li> The table has the same name as the name recorded in the
11593** changeset, and
11594** <li> The table has at least as many columns as recorded in the
11595** changeset, and
11596** <li> The table has primary key columns in the same position as
11597** recorded in the changeset.
11598** </ul>
11599**
11600** If there is no compatible table, it is not an error, but none of the
11601** changes associated with the table are applied. A warning message is issued
11602** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
11603** one such warning is issued for each table in the changeset.
11604**
11605** For each change for which there is a compatible table, an attempt is made
11606** to modify the table contents according to the UPDATE, INSERT or DELETE
11607** change. If a change cannot be applied cleanly, the conflict handler
11608** function passed as the fifth argument to sqlite3changeset_apply() may be
11609** invoked. A description of exactly when the conflict handler is invoked for
11610** each type of change is below.
11611**
11612** Unlike the xFilter argument, xConflict may not be passed NULL. The results
11613** of passing anything other than a valid function pointer as the xConflict
11614** argument are undefined.
11615**
11616** Each time the conflict handler function is invoked, it must return one
11617** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
11618** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
11619** if the second argument passed to the conflict handler is either
11620** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
11621** returns an illegal value, any changes already made are rolled back and
11622** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
11623** actions are taken by sqlite3changeset_apply() depending on the value
11624** returned by each invocation of the conflict-handler function. Refer to
11625** the documentation for the three
11626** [SQLITE_CHANGESET_OMIT|available return values] for details.
11627**
11628** <dl>
11629** <dt>DELETE Changes<dd>
11630** For each DELETE change, the function checks if the target database
11631** contains a row with the same primary key value (or values) as the
11632** original row values stored in the changeset. If it does, and the values
11633** stored in all non-primary key columns also match the values stored in
11634** the changeset the row is deleted from the target database.
11635**
11636** If a row with matching primary key values is found, but one or more of
11637** the non-primary key fields contains a value different from the original
11638** row value stored in the changeset, the conflict-handler function is
11639** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
11640** database table has more columns than are recorded in the changeset,
11641** only the values of those non-primary key fields are compared against
11642** the current database contents - any trailing database table columns
11643** are ignored.
11644**
11645** If no row with matching primary key values is found in the database,
11646** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11647** passed as the second argument.
11648**
11649** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
11650** (which can only happen if a foreign key constraint is violated), the
11651** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
11652** passed as the second argument. This includes the case where the DELETE
11653** operation is attempted because an earlier call to the conflict handler
11654** function returned [SQLITE_CHANGESET_REPLACE].
11655**
11656** <dt>INSERT Changes<dd>
11657** For each INSERT change, an attempt is made to insert the new row into
11658** the database. If the changeset row contains fewer fields than the
11659** database table, the trailing fields are populated with their default
11660** values.
11661**
11662** If the attempt to insert the row fails because the database already
11663** contains a row with the same primary key values, the conflict handler
11664** function is invoked with the second argument set to
11665** [SQLITE_CHANGESET_CONFLICT].
11666**
11667** If the attempt to insert the row fails because of some other constraint
11668** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
11669** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
11670** This includes the case where the INSERT operation is re-attempted because
11671** an earlier call to the conflict handler function returned
11672** [SQLITE_CHANGESET_REPLACE].
11673**
11674** <dt>UPDATE Changes<dd>
11675** For each UPDATE change, the function checks if the target database
11676** contains a row with the same primary key value (or values) as the
11677** original row values stored in the changeset. If it does, and the values
11678** stored in all modified non-primary key columns also match the values
11679** stored in the changeset the row is updated within the target database.
11680**
11681** If a row with matching primary key values is found, but one or more of
11682** the modified non-primary key fields contains a value different from an
11683** original row value stored in the changeset, the conflict-handler function
11684** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
11685** UPDATE changes only contain values for non-primary key fields that are
11686** to be modified, only those fields need to match the original values to
11687** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
11688**
11689** If no row with matching primary key values is found in the database,
11690** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
11691** passed as the second argument.
11692**
11693** If the UPDATE operation is attempted, but SQLite returns
11694** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
11695** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
11696** This includes the case where the UPDATE operation is attempted after
11697** an earlier call to the conflict handler function returned
11698** [SQLITE_CHANGESET_REPLACE].
11699** </dl>
11700**
11701** It is safe to execute SQL statements, including those that write to the
11702** table that the callback related to, from within the xConflict callback.
11703** This can be used to further customize the application's conflict
11704** resolution strategy.
11705**
11706** All changes made by these functions are enclosed in a savepoint transaction.
11707** If any other error (aside from a constraint failure when attempting to
11708** write to the target database) occurs, then the savepoint transaction is
11709** rolled back, restoring the target database to its original state, and an
11710** SQLite error code returned.
11711**
11712** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
11713** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
11714** may set (*ppRebase) to point to a "rebase" that may be used with the
11715** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
11716** is set to the size of the buffer in bytes. It is the responsibility of the
11717** caller to eventually free any such buffer using sqlite3_free(). The buffer
11718** is only allocated and populated if one or more conflicts were encountered
11719** while applying the patchset. See comments surrounding the sqlite3_rebaser
11720** APIs for further details.
11721**
11722** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
11723** may be modified by passing a combination of
11724** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
11725**
11726** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
11727** and therefore subject to change.
11728*/
11729SQLITE_API int sqlite3changeset_apply(
11730 sqlite3 *db, /* Apply change to "main" db of this handle */
11731 int nChangeset, /* Size of changeset in bytes */
11732 void *pChangeset, /* Changeset blob */
11733 int(*xFilter)(
11734 void *pCtx, /* Copy of sixth arg to _apply() */
11735 const char *zTab /* Table name */
11736 ),
11737 int(*xConflict)(
11738 void *pCtx, /* Copy of sixth arg to _apply() */
11739 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11740 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11741 ),
11742 void *pCtx /* First argument passed to xConflict */
11743);
11744SQLITE_API int sqlite3changeset_apply_v2(
11745 sqlite3 *db, /* Apply change to "main" db of this handle */
11746 int nChangeset, /* Size of changeset in bytes */
11747 void *pChangeset, /* Changeset blob */
11748 int(*xFilter)(
11749 void *pCtx, /* Copy of sixth arg to _apply() */
11750 const char *zTab /* Table name */
11751 ),
11752 int(*xConflict)(
11753 void *pCtx, /* Copy of sixth arg to _apply() */
11754 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
11755 sqlite3_changeset_iter *p /* Handle describing change and conflict */
11756 ),
11757 void *pCtx, /* First argument passed to xConflict */
11758 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
11759 int flags /* SESSION_CHANGESETAPPLY_* flags */
11760);
11761
11762/*
11763** CAPI3REF: Flags for sqlite3changeset_apply_v2
11764**
11765** The following flags may passed via the 9th parameter to
11766** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
11767**
11768** <dl>
11769** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
11770** Usually, the sessions module encloses all operations performed by
11771** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
11772** SAVEPOINT is committed if the changeset or patchset is successfully
11773** applied, or rolled back if an error occurs. Specifying this flag
11774** causes the sessions module to omit this savepoint. In this case, if the
11775** caller has an open transaction or savepoint when apply_v2() is called,
11776** it may revert the partially applied changeset by rolling it back.
11777**
11778** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11779** Invert the changeset before applying it. This is equivalent to inverting
11780** a changeset using sqlite3changeset_invert() before applying it. It is
11781** an error to specify this flag with a patchset.
11782*/
11783#define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
11784#define SQLITE_CHANGESETAPPLY_INVERT 0x0002
11785
11786/*
11787** CAPI3REF: Constants Passed To The Conflict Handler
11788**
11789** Values that may be passed as the second argument to a conflict-handler.
11790**
11791** <dl>
11792** <dt>SQLITE_CHANGESET_DATA<dd>
11793** The conflict handler is invoked with CHANGESET_DATA as the second argument
11794** when processing a DELETE or UPDATE change if a row with the required
11795** PRIMARY KEY fields is present in the database, but one or more other
11796** (non primary-key) fields modified by the update do not contain the
11797** expected "before" values.
11798**
11799** The conflicting row, in this case, is the database row with the matching
11800** primary key.
11801**
11802** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
11803** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
11804** argument when processing a DELETE or UPDATE change if a row with the
11805** required PRIMARY KEY fields is not present in the database.
11806**
11807** There is no conflicting row in this case. The results of invoking the
11808** sqlite3changeset_conflict() API are undefined.
11809**
11810** <dt>SQLITE_CHANGESET_CONFLICT<dd>
11811** CHANGESET_CONFLICT is passed as the second argument to the conflict
11812** handler while processing an INSERT change if the operation would result
11813** in duplicate primary key values.
11814**
11815** The conflicting row in this case is the database row with the matching
11816** primary key.
11817**
11818** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
11819** If foreign key handling is enabled, and applying a changeset leaves the
11820** database in a state containing foreign key violations, the conflict
11821** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
11822** exactly once before the changeset is committed. If the conflict handler
11823** returns CHANGESET_OMIT, the changes, including those that caused the
11824** foreign key constraint violation, are committed. Or, if it returns
11825** CHANGESET_ABORT, the changeset is rolled back.
11826**
11827** No current or conflicting row information is provided. The only function
11828** it is possible to call on the supplied sqlite3_changeset_iter handle
11829** is sqlite3changeset_fk_conflicts().
11830**
11831** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
11832** If any other constraint violation occurs while applying a change (i.e.
11833** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
11834** invoked with CHANGESET_CONSTRAINT as the second argument.
11835**
11836** There is no conflicting row in this case. The results of invoking the
11837** sqlite3changeset_conflict() API are undefined.
11838**
11839** </dl>
11840*/
11841#define SQLITE_CHANGESET_DATA 1
11842#define SQLITE_CHANGESET_NOTFOUND 2
11843#define SQLITE_CHANGESET_CONFLICT 3
11844#define SQLITE_CHANGESET_CONSTRAINT 4
11845#define SQLITE_CHANGESET_FOREIGN_KEY 5
11846
11847/*
11848** CAPI3REF: Constants Returned By The Conflict Handler
11849**
11850** A conflict handler callback must return one of the following three values.
11851**
11852** <dl>
11853** <dt>SQLITE_CHANGESET_OMIT<dd>
11854** If a conflict handler returns this value no special action is taken. The
11855** change that caused the conflict is not applied. The session module
11856** continues to the next change in the changeset.
11857**
11858** <dt>SQLITE_CHANGESET_REPLACE<dd>
11859** This value may only be returned if the second argument to the conflict
11860** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
11861** is not the case, any changes applied so far are rolled back and the
11862** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
11863**
11864** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
11865** handler, then the conflicting row is either updated or deleted, depending
11866** on the type of change.
11867**
11868** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
11869** handler, then the conflicting row is removed from the database and a
11870** second attempt to apply the change is made. If this second attempt fails,
11871** the original row is restored to the database before continuing.
11872**
11873** <dt>SQLITE_CHANGESET_ABORT<dd>
11874** If this value is returned, any changes applied so far are rolled back
11875** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
11876** </dl>
11877*/
11878#define SQLITE_CHANGESET_OMIT 0
11879#define SQLITE_CHANGESET_REPLACE 1
11880#define SQLITE_CHANGESET_ABORT 2
11881
11882/*
11883** CAPI3REF: Rebasing changesets
11884** EXPERIMENTAL
11885**
11886** Suppose there is a site hosting a database in state S0. And that
11887** modifications are made that move that database to state S1 and a
11888** changeset recorded (the "local" changeset). Then, a changeset based
11889** on S0 is received from another site (the "remote" changeset) and
11890** applied to the database. The database is then in state
11891** (S1+"remote"), where the exact state depends on any conflict
11892** resolution decisions (OMIT or REPLACE) made while applying "remote".
11893** Rebasing a changeset is to update it to take those conflict
11894** resolution decisions into account, so that the same conflicts
11895** do not have to be resolved elsewhere in the network.
11896**
11897** For example, if both the local and remote changesets contain an
11898** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
11899**
11900** local: INSERT INTO t1 VALUES(1, 'v1');
11901** remote: INSERT INTO t1 VALUES(1, 'v2');
11902**
11903** and the conflict resolution is REPLACE, then the INSERT change is
11904** removed from the local changeset (it was overridden). Or, if the
11905** conflict resolution was "OMIT", then the local changeset is modified
11906** to instead contain:
11907**
11908** UPDATE t1 SET b = 'v2' WHERE a=1;
11909**
11910** Changes within the local changeset are rebased as follows:
11911**
11912** <dl>
11913** <dt>Local INSERT<dd>
11914** This may only conflict with a remote INSERT. If the conflict
11915** resolution was OMIT, then add an UPDATE change to the rebased
11916** changeset. Or, if the conflict resolution was REPLACE, add
11917** nothing to the rebased changeset.
11918**
11919** <dt>Local DELETE<dd>
11920** This may conflict with a remote UPDATE or DELETE. In both cases the
11921** only possible resolution is OMIT. If the remote operation was a
11922** DELETE, then add no change to the rebased changeset. If the remote
11923** operation was an UPDATE, then the old.* fields of change are updated
11924** to reflect the new.* values in the UPDATE.
11925**
11926** <dt>Local UPDATE<dd>
11927** This may conflict with a remote UPDATE or DELETE. If it conflicts
11928** with a DELETE, and the conflict resolution was OMIT, then the update
11929** is changed into an INSERT. Any undefined values in the new.* record
11930** from the update change are filled in using the old.* values from
11931** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
11932** the UPDATE change is simply omitted from the rebased changeset.
11933**
11934** If conflict is with a remote UPDATE and the resolution is OMIT, then
11935** the old.* values are rebased using the new.* values in the remote
11936** change. Or, if the resolution is REPLACE, then the change is copied
11937** into the rebased changeset with updates to columns also updated by
11938** the conflicting remote UPDATE removed. If this means no columns would
11939** be updated, the change is omitted.
11940** </dl>
11941**
11942** A local change may be rebased against multiple remote changes
11943** simultaneously. If a single key is modified by multiple remote
11944** changesets, they are combined as follows before the local changeset
11945** is rebased:
11946**
11947** <ul>
11948** <li> If there has been one or more REPLACE resolutions on a
11949** key, it is rebased according to a REPLACE.
11950**
11951** <li> If there have been no REPLACE resolutions on a key, then
11952** the local changeset is rebased according to the most recent
11953** of the OMIT resolutions.
11954** </ul>
11955**
11956** Note that conflict resolutions from multiple remote changesets are
11957** combined on a per-field basis, not per-row. This means that in the
11958** case of multiple remote UPDATE operations, some fields of a single
11959** local change may be rebased for REPLACE while others are rebased for
11960** OMIT.
11961**
11962** In order to rebase a local changeset, the remote changeset must first
11963** be applied to the local database using sqlite3changeset_apply_v2() and
11964** the buffer of rebase information captured. Then:
11965**
11966** <ol>
11967** <li> An sqlite3_rebaser object is created by calling
11968** sqlite3rebaser_create().
11969** <li> The new object is configured with the rebase buffer obtained from
11970** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
11971** If the local changeset is to be rebased against multiple remote
11972** changesets, then sqlite3rebaser_configure() should be called
11973** multiple times, in the same order that the multiple
11974** sqlite3changeset_apply_v2() calls were made.
11975** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
11976** <li> The sqlite3_rebaser object is deleted by calling
11977** sqlite3rebaser_delete().
11978** </ol>
11979*/
11980typedef struct sqlite3_rebaser sqlite3_rebaser;
11981
11982/*
11983** CAPI3REF: Create a changeset rebaser object.
11984** EXPERIMENTAL
11985**
11986** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
11987** point to the new object and return SQLITE_OK. Otherwise, if an error
11988** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
11989** to NULL.
11990*/
11991SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
11992
11993/*
11994** CAPI3REF: Configure a changeset rebaser object.
11995** EXPERIMENTAL
11996**
11997** Configure the changeset rebaser object to rebase changesets according
11998** to the conflict resolutions described by buffer pRebase (size nRebase
11999** bytes), which must have been obtained from a previous call to
12000** sqlite3changeset_apply_v2().
12001*/
12002SQLITE_API int sqlite3rebaser_configure(
12003 sqlite3_rebaser*,
12004 int nRebase, const void *pRebase
12005);
12006
12007/*
12008** CAPI3REF: Rebase a changeset
12009** EXPERIMENTAL
12010**
12011** Argument pIn must point to a buffer containing a changeset nIn bytes
12012** in size. This function allocates and populates a buffer with a copy
12013** of the changeset rebased according to the configuration of the
12014** rebaser object passed as the first argument. If successful, (*ppOut)
12015** is set to point to the new buffer containing the rebased changeset and
12016** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12017** responsibility of the caller to eventually free the new buffer using
12018** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12019** are set to zero and an SQLite error code returned.
12020*/
12021SQLITE_API int sqlite3rebaser_rebase(
12022 sqlite3_rebaser*,
12023 int nIn, const void *pIn,
12024 int *pnOut, void **ppOut
12025);
12026
12027/*
12028** CAPI3REF: Delete a changeset rebaser object.
12029** EXPERIMENTAL
12030**
12031** Delete the changeset rebaser object and all associated resources. There
12032** should be one call to this function for each successful invocation
12033** of sqlite3rebaser_create().
12034*/
12035SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12036
12037/*
12038** CAPI3REF: Streaming Versions of API functions.
12039**
12040** The six streaming API xxx_strm() functions serve similar purposes to the
12041** corresponding non-streaming API functions:
12042**
12043** <table border=1 style="margin-left:8ex;margin-right:8ex">
12044** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12045** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12046** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12047** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12048** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12049** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12050** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12051** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12052** </table>
12053**
12054** Non-streaming functions that accept changesets (or patchsets) as input
12055** require that the entire changeset be stored in a single buffer in memory.
12056** Similarly, those that return a changeset or patchset do so by returning
12057** a pointer to a single large buffer allocated using sqlite3_malloc().
12058** Normally this is convenient. However, if an application running in a
12059** low-memory environment is required to handle very large changesets, the
12060** large contiguous memory allocations required can become onerous.
12061**
12062** In order to avoid this problem, instead of a single large buffer, input
12063** is passed to a streaming API functions by way of a callback function that
12064** the sessions module invokes to incrementally request input data as it is
12065** required. In all cases, a pair of API function parameters such as
12066**
12067** <pre>
12068** &nbsp; int nChangeset,
12069** &nbsp; void *pChangeset,
12070** </pre>
12071**
12072** Is replaced by:
12073**
12074** <pre>
12075** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
12076** &nbsp; void *pIn,
12077** </pre>
12078**
12079** Each time the xInput callback is invoked by the sessions module, the first
12080** argument passed is a copy of the supplied pIn context pointer. The second
12081** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
12082** error occurs the xInput method should copy up to (*pnData) bytes of data
12083** into the buffer and set (*pnData) to the actual number of bytes copied
12084** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
12085** should be set to zero to indicate this. Or, if an error occurs, an SQLite
12086** error code should be returned. In all cases, if an xInput callback returns
12087** an error, all processing is abandoned and the streaming API function
12088** returns a copy of the error code to the caller.
12089**
12090** In the case of sqlite3changeset_start_strm(), the xInput callback may be
12091** invoked by the sessions module at any point during the lifetime of the
12092** iterator. If such an xInput callback returns an error, the iterator enters
12093** an error state, whereby all subsequent calls to iterator functions
12094** immediately fail with the same error code as returned by xInput.
12095**
12096** Similarly, streaming API functions that return changesets (or patchsets)
12097** return them in chunks by way of a callback function instead of via a
12098** pointer to a single large buffer. In this case, a pair of parameters such
12099** as:
12100**
12101** <pre>
12102** &nbsp; int *pnChangeset,
12103** &nbsp; void **ppChangeset,
12104** </pre>
12105**
12106** Is replaced by:
12107**
12108** <pre>
12109** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
12110** &nbsp; void *pOut
12111** </pre>
12112**
12113** The xOutput callback is invoked zero or more times to return data to
12114** the application. The first parameter passed to each call is a copy of the
12115** pOut pointer supplied by the application. The second parameter, pData,
12116** points to a buffer nData bytes in size containing the chunk of output
12117** data being returned. If the xOutput callback successfully processes the
12118** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
12119** it should return some other SQLite error code. In this case processing
12120** is immediately abandoned and the streaming API function returns a copy
12121** of the xOutput error code to the application.
12122**
12123** The sessions module never invokes an xOutput callback with the third
12124** parameter set to a value less than or equal to zero. Other than this,
12125** no guarantees are made as to the size of the chunks of data returned.
12126*/
12127SQLITE_API int sqlite3changeset_apply_strm(
12128 sqlite3 *db, /* Apply change to "main" db of this handle */
12129 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12130 void *pIn, /* First arg for xInput */
12131 int(*xFilter)(
12132 void *pCtx, /* Copy of sixth arg to _apply() */
12133 const char *zTab /* Table name */
12134 ),
12135 int(*xConflict)(
12136 void *pCtx, /* Copy of sixth arg to _apply() */
12137 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12138 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12139 ),
12140 void *pCtx /* First argument passed to xConflict */
12141);
12142SQLITE_API int sqlite3changeset_apply_v2_strm(
12143 sqlite3 *db, /* Apply change to "main" db of this handle */
12144 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12145 void *pIn, /* First arg for xInput */
12146 int(*xFilter)(
12147 void *pCtx, /* Copy of sixth arg to _apply() */
12148 const char *zTab /* Table name */
12149 ),
12150 int(*xConflict)(
12151 void *pCtx, /* Copy of sixth arg to _apply() */
12152 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12153 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12154 ),
12155 void *pCtx, /* First argument passed to xConflict */
12156 void **ppRebase, int *pnRebase,
12157 int flags
12158);
12159SQLITE_API int sqlite3changeset_concat_strm(
12160 int (*xInputA)(void *pIn, void *pData, int *pnData),
12161 void *pInA,
12162 int (*xInputB)(void *pIn, void *pData, int *pnData),
12163 void *pInB,
12164 int (*xOutput)(void *pOut, const void *pData, int nData),
12165 void *pOut
12166);
12167SQLITE_API int sqlite3changeset_invert_strm(
12168 int (*xInput)(void *pIn, void *pData, int *pnData),
12169 void *pIn,
12170 int (*xOutput)(void *pOut, const void *pData, int nData),
12171 void *pOut
12172);
12173SQLITE_API int sqlite3changeset_start_strm(
12174 sqlite3_changeset_iter **pp,
12175 int (*xInput)(void *pIn, void *pData, int *pnData),
12176 void *pIn
12177);
12178SQLITE_API int sqlite3changeset_start_v2_strm(
12179 sqlite3_changeset_iter **pp,
12180 int (*xInput)(void *pIn, void *pData, int *pnData),
12181 void *pIn,
12182 int flags
12183);
12184SQLITE_API int sqlite3session_changeset_strm(
12185 sqlite3_session *pSession,
12186 int (*xOutput)(void *pOut, const void *pData, int nData),
12187 void *pOut
12188);
12189SQLITE_API int sqlite3session_patchset_strm(
12190 sqlite3_session *pSession,
12191 int (*xOutput)(void *pOut, const void *pData, int nData),
12192 void *pOut
12193);
12194SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
12195 int (*xInput)(void *pIn, void *pData, int *pnData),
12196 void *pIn
12197);
12198SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
12199 int (*xOutput)(void *pOut, const void *pData, int nData),
12200 void *pOut
12201);
12202SQLITE_API int sqlite3rebaser_rebase_strm(
12203 sqlite3_rebaser *pRebaser,
12204 int (*xInput)(void *pIn, void *pData, int *pnData),
12205 void *pIn,
12206 int (*xOutput)(void *pOut, const void *pData, int nData),
12207 void *pOut
12208);
12209
12210/*
12211** CAPI3REF: Configure global parameters
12212**
12213** The sqlite3session_config() interface is used to make global configuration
12214** changes to the sessions module in order to tune it to the specific needs
12215** of the application.
12216**
12217** The sqlite3session_config() interface is not threadsafe. If it is invoked
12218** while any other thread is inside any other sessions method then the
12219** results are undefined. Furthermore, if it is invoked after any sessions
12220** related objects have been created, the results are also undefined.
12221**
12222** The first argument to the sqlite3session_config() function must be one
12223** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
12224** interpretation of the (void*) value passed as the second parameter and
12225** the effect of calling this function depends on the value of the first
12226** parameter.
12227**
12228** <dl>
12229** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
12230** By default, the sessions module streaming interfaces attempt to input
12231** and output data in approximately 1 KiB chunks. This operand may be used
12232** to set and query the value of this configuration setting. The pointer
12233** passed as the second argument must point to a value of type (int).
12234** If this value is greater than 0, it is used as the new streaming data
12235** chunk size for both input and output. Before returning, the (int) value
12236** pointed to by pArg is set to the final value of the streaming interface
12237** chunk size.
12238** </dl>
12239**
12240** This function returns SQLITE_OK if successful, or an SQLite error code
12241** otherwise.
12242*/
12243SQLITE_API int sqlite3session_config(int op, void *pArg);
12244
12245/*
12246** CAPI3REF: Values for sqlite3session_config().
12247*/
12248#define SQLITE_SESSION_CONFIG_STRMSIZE 1
12249
12250/*
12251** Make sure we can call this stuff from C++.
12252*/
12253#ifdef __cplusplus
12254}
12255#endif
12256
12257#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
12258
12259/******** End of sqlite3session.h *********/
12260/******** Begin file fts5.h *********/
12261/*
12262** 2014 May 31
12263**
12264** The author disclaims copyright to this source code. In place of
12265** a legal notice, here is a blessing:
12266**
12267** May you do good and not evil.
12268** May you find forgiveness for yourself and forgive others.
12269** May you share freely, never taking more than you give.
12270**
12271******************************************************************************
12272**
12273** Interfaces to extend FTS5. Using the interfaces defined in this file,
12274** FTS5 may be extended with:
12275**
12276** * custom tokenizers, and
12277** * custom auxiliary functions.
12278*/
12279
12280
12281#ifndef _FTS5_H
12282#define _FTS5_H
12283
12284
12285#ifdef __cplusplus
12286extern "C" {
12287#endif
12288
12289/*************************************************************************
12290** CUSTOM AUXILIARY FUNCTIONS
12291**
12292** Virtual table implementations may overload SQL functions by implementing
12293** the sqlite3_module.xFindFunction() method.
12294*/
12295
12296typedef struct Fts5ExtensionApi Fts5ExtensionApi;
12297typedef struct Fts5Context Fts5Context;
12298typedef struct Fts5PhraseIter Fts5PhraseIter;
12299
12300typedef void (*fts5_extension_function)(
12301 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
12302 Fts5Context *pFts, /* First arg to pass to pApi functions */
12303 sqlite3_context *pCtx, /* Context for returning result/error */
12304 int nVal, /* Number of values in apVal[] array */
12305 sqlite3_value **apVal /* Array of trailing arguments */
12306);
12307
12308struct Fts5PhraseIter {
12309 const unsigned char *a;
12310 const unsigned char *b;
12311};
12312
12313/*
12314** EXTENSION API FUNCTIONS
12315**
12316** xUserData(pFts):
12317** Return a copy of the context pointer the extension function was
12318** registered with.
12319**
12320** xColumnTotalSize(pFts, iCol, pnToken):
12321** If parameter iCol is less than zero, set output variable *pnToken
12322** to the total number of tokens in the FTS5 table. Or, if iCol is
12323** non-negative but less than the number of columns in the table, return
12324** the total number of tokens in column iCol, considering all rows in
12325** the FTS5 table.
12326**
12327** If parameter iCol is greater than or equal to the number of columns
12328** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12329** an OOM condition or IO error), an appropriate SQLite error code is
12330** returned.
12331**
12332** xColumnCount(pFts):
12333** Return the number of columns in the table.
12334**
12335** xColumnSize(pFts, iCol, pnToken):
12336** If parameter iCol is less than zero, set output variable *pnToken
12337** to the total number of tokens in the current row. Or, if iCol is
12338** non-negative but less than the number of columns in the table, set
12339** *pnToken to the number of tokens in column iCol of the current row.
12340**
12341** If parameter iCol is greater than or equal to the number of columns
12342** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12343** an OOM condition or IO error), an appropriate SQLite error code is
12344** returned.
12345**
12346** This function may be quite inefficient if used with an FTS5 table
12347** created with the "columnsize=0" option.
12348**
12349** xColumnText:
12350** This function attempts to retrieve the text of column iCol of the
12351** current document. If successful, (*pz) is set to point to a buffer
12352** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
12353** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
12354** if an error occurs, an SQLite error code is returned and the final values
12355** of (*pz) and (*pn) are undefined.
12356**
12357** xPhraseCount:
12358** Returns the number of phrases in the current query expression.
12359**
12360** xPhraseSize:
12361** Returns the number of tokens in phrase iPhrase of the query. Phrases
12362** are numbered starting from zero.
12363**
12364** xInstCount:
12365** Set *pnInst to the total number of occurrences of all phrases within
12366** the query within the current row. Return SQLITE_OK if successful, or
12367** an error code (i.e. SQLITE_NOMEM) if an error occurs.
12368**
12369** This API can be quite slow if used with an FTS5 table created with the
12370** "detail=none" or "detail=column" option. If the FTS5 table is created
12371** with either "detail=none" or "detail=column" and "content=" option
12372** (i.e. if it is a contentless table), then this API always returns 0.
12373**
12374** xInst:
12375** Query for the details of phrase match iIdx within the current row.
12376** Phrase matches are numbered starting from zero, so the iIdx argument
12377** should be greater than or equal to zero and smaller than the value
12378** output by xInstCount().
12379**
12380** Usually, output parameter *piPhrase is set to the phrase number, *piCol
12381** to the column in which it occurs and *piOff the token offset of the
12382** first token of the phrase. Returns SQLITE_OK if successful, or an error
12383** code (i.e. SQLITE_NOMEM) if an error occurs.
12384**
12385** This API can be quite slow if used with an FTS5 table created with the
12386** "detail=none" or "detail=column" option.
12387**
12388** xRowid:
12389** Returns the rowid of the current row.
12390**
12391** xTokenize:
12392** Tokenize text using the tokenizer belonging to the FTS5 table.
12393**
12394** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
12395** This API function is used to query the FTS table for phrase iPhrase
12396** of the current query. Specifically, a query equivalent to:
12397**
12398** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
12399**
12400** with $p set to a phrase equivalent to the phrase iPhrase of the
12401** current query is executed. Any column filter that applies to
12402** phrase iPhrase of the current query is included in $p. For each
12403** row visited, the callback function passed as the fourth argument
12404** is invoked. The context and API objects passed to the callback
12405** function may be used to access the properties of each matched row.
12406** Invoking Api.xUserData() returns a copy of the pointer passed as
12407** the third argument to pUserData.
12408**
12409** If the callback function returns any value other than SQLITE_OK, the
12410** query is abandoned and the xQueryPhrase function returns immediately.
12411** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
12412** Otherwise, the error code is propagated upwards.
12413**
12414** If the query runs to completion without incident, SQLITE_OK is returned.
12415** Or, if some error occurs before the query completes or is aborted by
12416** the callback, an SQLite error code is returned.
12417**
12418**
12419** xSetAuxdata(pFts5, pAux, xDelete)
12420**
12421** Save the pointer passed as the second argument as the extension function's
12422** "auxiliary data". The pointer may then be retrieved by the current or any
12423** future invocation of the same fts5 extension function made as part of
12424** the same MATCH query using the xGetAuxdata() API.
12425**
12426** Each extension function is allocated a single auxiliary data slot for
12427** each FTS query (MATCH expression). If the extension function is invoked
12428** more than once for a single FTS query, then all invocations share a
12429** single auxiliary data context.
12430**
12431** If there is already an auxiliary data pointer when this function is
12432** invoked, then it is replaced by the new pointer. If an xDelete callback
12433** was specified along with the original pointer, it is invoked at this
12434** point.
12435**
12436** The xDelete callback, if one is specified, is also invoked on the
12437** auxiliary data pointer after the FTS5 query has finished.
12438**
12439** If an error (e.g. an OOM condition) occurs within this function,
12440** the auxiliary data is set to NULL and an error code returned. If the
12441** xDelete parameter was not NULL, it is invoked on the auxiliary data
12442** pointer before returning.
12443**
12444**
12445** xGetAuxdata(pFts5, bClear)
12446**
12447** Returns the current auxiliary data pointer for the fts5 extension
12448** function. See the xSetAuxdata() method for details.
12449**
12450** If the bClear argument is non-zero, then the auxiliary data is cleared
12451** (set to NULL) before this function returns. In this case the xDelete,
12452** if any, is not invoked.
12453**
12454**
12455** xRowCount(pFts5, pnRow)
12456**
12457** This function is used to retrieve the total number of rows in the table.
12458** In other words, the same value that would be returned by:
12459**
12460** SELECT count(*) FROM ftstable;
12461**
12462** xPhraseFirst()
12463** This function is used, along with type Fts5PhraseIter and the xPhraseNext
12464** method, to iterate through all instances of a single query phrase within
12465** the current row. This is the same information as is accessible via the
12466** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
12467** to use, this API may be faster under some circumstances. To iterate
12468** through instances of phrase iPhrase, use the following code:
12469**
12470** Fts5PhraseIter iter;
12471** int iCol, iOff;
12472** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
12473** iCol>=0;
12474** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
12475** ){
12476** // An instance of phrase iPhrase at offset iOff of column iCol
12477** }
12478**
12479** The Fts5PhraseIter structure is defined above. Applications should not
12480** modify this structure directly - it should only be used as shown above
12481** with the xPhraseFirst() and xPhraseNext() API methods (and by
12482** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
12483**
12484** This API can be quite slow if used with an FTS5 table created with the
12485** "detail=none" or "detail=column" option. If the FTS5 table is created
12486** with either "detail=none" or "detail=column" and "content=" option
12487** (i.e. if it is a contentless table), then this API always iterates
12488** through an empty set (all calls to xPhraseFirst() set iCol to -1).
12489**
12490** xPhraseNext()
12491** See xPhraseFirst above.
12492**
12493** xPhraseFirstColumn()
12494** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
12495** and xPhraseNext() APIs described above. The difference is that instead
12496** of iterating through all instances of a phrase in the current row, these
12497** APIs are used to iterate through the set of columns in the current row
12498** that contain one or more instances of a specified phrase. For example:
12499**
12500** Fts5PhraseIter iter;
12501** int iCol;
12502** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
12503** iCol>=0;
12504** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
12505** ){
12506** // Column iCol contains at least one instance of phrase iPhrase
12507** }
12508**
12509** This API can be quite slow if used with an FTS5 table created with the
12510** "detail=none" option. If the FTS5 table is created with either
12511** "detail=none" "content=" option (i.e. if it is a contentless table),
12512** then this API always iterates through an empty set (all calls to
12513** xPhraseFirstColumn() set iCol to -1).
12514**
12515** The information accessed using this API and its companion
12516** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
12517** (or xInst/xInstCount). The chief advantage of this API is that it is
12518** significantly more efficient than those alternatives when used with
12519** "detail=column" tables.
12520**
12521** xPhraseNextColumn()
12522** See xPhraseFirstColumn above.
12523*/
12524struct Fts5ExtensionApi {
12525 int iVersion; /* Currently always set to 3 */
12526
12527 void *(*xUserData)(Fts5Context*);
12528
12529 int (*xColumnCount)(Fts5Context*);
12530 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
12531 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
12532
12533 int (*xTokenize)(Fts5Context*,
12534 const char *pText, int nText, /* Text to tokenize */
12535 void *pCtx, /* Context passed to xToken() */
12536 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
12537 );
12538
12539 int (*xPhraseCount)(Fts5Context*);
12540 int (*xPhraseSize)(Fts5Context*, int iPhrase);
12541
12542 int (*xInstCount)(Fts5Context*, int *pnInst);
12543 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
12544
12545 sqlite3_int64 (*xRowid)(Fts5Context*);
12546 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
12547 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
12548
12549 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
12550 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
12551 );
12552 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
12553 void *(*xGetAuxdata)(Fts5Context*, int bClear);
12554
12555 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
12556 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
12557
12558 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
12559 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
12560};
12561
12562/*
12563** CUSTOM AUXILIARY FUNCTIONS
12564*************************************************************************/
12565
12566/*************************************************************************
12567** CUSTOM TOKENIZERS
12568**
12569** Applications may also register custom tokenizer types. A tokenizer
12570** is registered by providing fts5 with a populated instance of the
12571** following structure. All structure methods must be defined, setting
12572** any member of the fts5_tokenizer struct to NULL leads to undefined
12573** behaviour. The structure methods are expected to function as follows:
12574**
12575** xCreate:
12576** This function is used to allocate and initialize a tokenizer instance.
12577** A tokenizer instance is required to actually tokenize text.
12578**
12579** The first argument passed to this function is a copy of the (void*)
12580** pointer provided by the application when the fts5_tokenizer object
12581** was registered with FTS5 (the third argument to xCreateTokenizer()).
12582** The second and third arguments are an array of nul-terminated strings
12583** containing the tokenizer arguments, if any, specified following the
12584** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
12585** to create the FTS5 table.
12586**
12587** The final argument is an output variable. If successful, (*ppOut)
12588** should be set to point to the new tokenizer handle and SQLITE_OK
12589** returned. If an error occurs, some value other than SQLITE_OK should
12590** be returned. In this case, fts5 assumes that the final value of *ppOut
12591** is undefined.
12592**
12593** xDelete:
12594** This function is invoked to delete a tokenizer handle previously
12595** allocated using xCreate(). Fts5 guarantees that this function will
12596** be invoked exactly once for each successful call to xCreate().
12597**
12598** xTokenize:
12599** This function is expected to tokenize the nText byte string indicated
12600** by argument pText. pText may or may not be nul-terminated. The first
12601** argument passed to this function is a pointer to an Fts5Tokenizer object
12602** returned by an earlier call to xCreate().
12603**
12604** The second argument indicates the reason that FTS5 is requesting
12605** tokenization of the supplied text. This is always one of the following
12606** four values:
12607**
12608** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
12609** or removed from the FTS table. The tokenizer is being invoked to
12610** determine the set of tokens to add to (or delete from) the
12611** FTS index.
12612**
12613** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
12614** against the FTS index. The tokenizer is being called to tokenize
12615** a bareword or quoted string specified as part of the query.
12616**
12617** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
12618** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
12619** followed by a "*" character, indicating that the last token
12620** returned by the tokenizer will be treated as a token prefix.
12621**
12622** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
12623** satisfy an fts5_api.xTokenize() request made by an auxiliary
12624** function. Or an fts5_api.xColumnSize() request made by the same
12625** on a columnsize=0 database.
12626** </ul>
12627**
12628** For each token in the input string, the supplied callback xToken() must
12629** be invoked. The first argument to it should be a copy of the pointer
12630** passed as the second argument to xTokenize(). The third and fourth
12631** arguments are a pointer to a buffer containing the token text, and the
12632** size of the token in bytes. The 4th and 5th arguments are the byte offsets
12633** of the first byte of and first byte immediately following the text from
12634** which the token is derived within the input.
12635**
12636** The second argument passed to the xToken() callback ("tflags") should
12637** normally be set to 0. The exception is if the tokenizer supports
12638** synonyms. In this case see the discussion below for details.
12639**
12640** FTS5 assumes the xToken() callback is invoked for each token in the
12641** order that they occur within the input text.
12642**
12643** If an xToken() callback returns any value other than SQLITE_OK, then
12644** the tokenization should be abandoned and the xTokenize() method should
12645** immediately return a copy of the xToken() return value. Or, if the
12646** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
12647** if an error occurs with the xTokenize() implementation itself, it
12648** may abandon the tokenization and return any error code other than
12649** SQLITE_OK or SQLITE_DONE.
12650**
12651** SYNONYM SUPPORT
12652**
12653** Custom tokenizers may also support synonyms. Consider a case in which a
12654** user wishes to query for a phrase such as "first place". Using the
12655** built-in tokenizers, the FTS5 query 'first + place' will match instances
12656** of "first place" within the document set, but not alternative forms
12657** such as "1st place". In some applications, it would be better to match
12658** all instances of "first place" or "1st place" regardless of which form
12659** the user specified in the MATCH query text.
12660**
12661** There are several ways to approach this in FTS5:
12662**
12663** <ol><li> By mapping all synonyms to a single token. In this case, using
12664** the above example, this means that the tokenizer returns the
12665** same token for inputs "first" and "1st". Say that token is in
12666** fact "first", so that when the user inserts the document "I won
12667** 1st place" entries are added to the index for tokens "i", "won",
12668** "first" and "place". If the user then queries for '1st + place',
12669** the tokenizer substitutes "first" for "1st" and the query works
12670** as expected.
12671**
12672** <li> By querying the index for all synonyms of each query term
12673** separately. In this case, when tokenizing query text, the
12674** tokenizer may provide multiple synonyms for a single term
12675** within the document. FTS5 then queries the index for each
12676** synonym individually. For example, faced with the query:
12677**
12678** <codeblock>
12679** ... MATCH 'first place'</codeblock>
12680**
12681** the tokenizer offers both "1st" and "first" as synonyms for the
12682** first token in the MATCH query and FTS5 effectively runs a query
12683** similar to:
12684**
12685** <codeblock>
12686** ... MATCH '(first OR 1st) place'</codeblock>
12687**
12688** except that, for the purposes of auxiliary functions, the query
12689** still appears to contain just two phrases - "(first OR 1st)"
12690** being treated as a single phrase.
12691**
12692** <li> By adding multiple synonyms for a single term to the FTS index.
12693** Using this method, when tokenizing document text, the tokenizer
12694** provides multiple synonyms for each token. So that when a
12695** document such as "I won first place" is tokenized, entries are
12696** added to the FTS index for "i", "won", "first", "1st" and
12697** "place".
12698**
12699** This way, even if the tokenizer does not provide synonyms
12700** when tokenizing query text (it should not - to do so would be
12701** inefficient), it doesn't matter if the user queries for
12702** 'first + place' or '1st + place', as there are entries in the
12703** FTS index corresponding to both forms of the first token.
12704** </ol>
12705**
12706** Whether it is parsing document or query text, any call to xToken that
12707** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
12708** is considered to supply a synonym for the previous token. For example,
12709** when parsing the document "I won first place", a tokenizer that supports
12710** synonyms would call xToken() 5 times, as follows:
12711**
12712** <codeblock>
12713** xToken(pCtx, 0, "i", 1, 0, 1);
12714** xToken(pCtx, 0, "won", 3, 2, 5);
12715** xToken(pCtx, 0, "first", 5, 6, 11);
12716** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
12717** xToken(pCtx, 0, "place", 5, 12, 17);
12718**</codeblock>
12719**
12720** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
12721** xToken() is called. Multiple synonyms may be specified for a single token
12722** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
12723** There is no limit to the number of synonyms that may be provided for a
12724** single token.
12725**
12726** In many cases, method (1) above is the best approach. It does not add
12727** extra data to the FTS index or require FTS5 to query for multiple terms,
12728** so it is efficient in terms of disk space and query speed. However, it
12729** does not support prefix queries very well. If, as suggested above, the
12730** token "first" is substituted for "1st" by the tokenizer, then the query:
12731**
12732** <codeblock>
12733** ... MATCH '1s*'</codeblock>
12734**
12735** will not match documents that contain the token "1st" (as the tokenizer
12736** will probably not map "1s" to any prefix of "first").
12737**
12738** For full prefix support, method (3) may be preferred. In this case,
12739** because the index contains entries for both "first" and "1st", prefix
12740** queries such as 'fi*' or '1s*' will match correctly. However, because
12741** extra entries are added to the FTS index, this method uses more space
12742** within the database.
12743**
12744** Method (2) offers a midpoint between (1) and (3). Using this method,
12745** a query such as '1s*' will match documents that contain the literal
12746** token "1st", but not "first" (assuming the tokenizer is not able to
12747** provide synonyms for prefixes). However, a non-prefix query like '1st'
12748** will match against "1st" and "first". This method does not require
12749** extra disk space, as no extra entries are added to the FTS index.
12750** On the other hand, it may require more CPU cycles to run MATCH queries,
12751** as separate queries of the FTS index are required for each synonym.
12752**
12753** When using methods (2) or (3), it is important that the tokenizer only
12754** provide synonyms when tokenizing document text (method (2)) or query
12755** text (method (3)), not both. Doing so will not cause any errors, but is
12756** inefficient.
12757*/
12758typedef struct Fts5Tokenizer Fts5Tokenizer;
12759typedef struct fts5_tokenizer fts5_tokenizer;
12760struct fts5_tokenizer {
12761 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
12762 void (*xDelete)(Fts5Tokenizer*);
12763 int (*xTokenize)(Fts5Tokenizer*,
12764 void *pCtx,
12765 int flags, /* Mask of FTS5_TOKENIZE_* flags */
12766 const char *pText, int nText,
12767 int (*xToken)(
12768 void *pCtx, /* Copy of 2nd argument to xTokenize() */
12769 int tflags, /* Mask of FTS5_TOKEN_* flags */
12770 const char *pToken, /* Pointer to buffer containing token */
12771 int nToken, /* Size of token in bytes */
12772 int iStart, /* Byte offset of token within input text */
12773 int iEnd /* Byte offset of end of token within input text */
12774 )
12775 );
12776};
12777
12778/* Flags that may be passed as the third argument to xTokenize() */
12779#define FTS5_TOKENIZE_QUERY 0x0001
12780#define FTS5_TOKENIZE_PREFIX 0x0002
12781#define FTS5_TOKENIZE_DOCUMENT 0x0004
12782#define FTS5_TOKENIZE_AUX 0x0008
12783
12784/* Flags that may be passed by the tokenizer implementation back to FTS5
12785** as the third argument to the supplied xToken callback. */
12786#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
12787
12788/*
12789** END OF CUSTOM TOKENIZERS
12790*************************************************************************/
12791
12792/*************************************************************************
12793** FTS5 EXTENSION REGISTRATION API
12794*/
12795typedef struct fts5_api fts5_api;
12796struct fts5_api {
12797 int iVersion; /* Currently always set to 2 */
12798
12799 /* Create a new tokenizer */
12800 int (*xCreateTokenizer)(
12801 fts5_api *pApi,
12802 const char *zName,
12803 void *pContext,
12804 fts5_tokenizer *pTokenizer,
12805 void (*xDestroy)(void*)
12806 );
12807
12808 /* Find an existing tokenizer */
12809 int (*xFindTokenizer)(
12810 fts5_api *pApi,
12811 const char *zName,
12812 void **ppContext,
12813 fts5_tokenizer *pTokenizer
12814 );
12815
12816 /* Create a new auxiliary function */
12817 int (*xCreateFunction)(
12818 fts5_api *pApi,
12819 const char *zName,
12820 void *pContext,
12821 fts5_extension_function xFunction,
12822 void (*xDestroy)(void*)
12823 );
12824};
12825
12826/*
12827** END OF REGISTRATION API
12828*************************************************************************/
12829
12830#ifdef __cplusplus
12831} /* end of the 'extern "C"' block */
12832#endif
12833
12834#endif /* _FTS5_H */
12835
12836/******** End of fts5.h *********/
12837