· 8 years ago · Dec 30, 2017, 02:10 AM
1/*
2** 2001 September 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** Provide the ability to override linkage features of the interface.
47*/
48#ifndef SQLITE_EXTERN
49# define SQLITE_EXTERN extern
50#endif
51#ifndef SQLITE_API
52# define SQLITE_API
53#endif
54#ifndef SQLITE_CDECL
55# define SQLITE_CDECL
56#endif
57#ifndef SQLITE_STDCALL
58# define SQLITE_STDCALL
59#endif
60
61/*
62** These no-op macros are used in front of interfaces to mark those
63** interfaces as either deprecated or experimental. New applications
64** should not use deprecated interfaces - they are supported for backwards
65** compatibility only. Application writers should be aware that
66** experimental interfaces are subject to change in point releases.
67**
68** These macros used to resolve to various kinds of compiler magic that
69** would generate warning messages when they were used. But that
70** compiler magic ended up generating such a flurry of bug reports
71** that we have taken it all out and gone back to using simple
72** noop macros.
73*/
74#define SQLITE_DEPRECATED
75#define SQLITE_EXPERIMENTAL
76
77/*
78** Ensure these symbols were not defined by some previous header file.
79*/
80#ifdef SQLITE_VERSION
81# undef SQLITE_VERSION
82#endif
83#ifdef SQLITE_VERSION_NUMBER
84# undef SQLITE_VERSION_NUMBER
85#endif
86
87/*
88** CAPI3REF: Compile-Time Library Version Numbers
89**
90** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
91** evaluates to a string literal that is the SQLite version in the
92** format "X.Y.Z" where X is the major version number (always 3 for
93** SQLite3) and Y is the minor version number and Z is the release number.)^
94** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
95** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
96** numbers used in [SQLITE_VERSION].)^
97** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
98** be larger than the release from which it is derived. Either Y will
99** be held constant and Z will be incremented or else Y will be incremented
100** and Z will be reset to zero.
101**
102** Since version 3.6.18, SQLite source code has been stored in the
103** <a href="http://www.fossil-scm.org/">Fossil configuration management
104** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
105** a string which identifies a particular check-in of SQLite
106** within its configuration management system. ^The SQLITE_SOURCE_ID
107** string contains the date and time of the check-in (UTC) and an SHA1
108** hash of the entire source tree.
109**
110** See also: [sqlite3_libversion()],
111** [sqlite3_libversion_number()], [sqlite3_sourceid()],
112** [sqlite_version()] and [sqlite_source_id()].
113*/
114#define SQLITE_VERSION "3.13.0"
115#define SQLITE_VERSION_NUMBER 3013000
116#define SQLITE_SOURCE_ID "2016-05-18 10:57:30 fc49f556e48970561d7ab6a2f24fdd7d9eb81ff2"
117
118/*
119** CAPI3REF: Run-Time Library Version Numbers
120** KEYWORDS: sqlite3_version, sqlite3_sourceid
121**
122** These interfaces provide the same information as the [SQLITE_VERSION],
123** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
124** but are associated with the library instead of the header file. ^(Cautious
125** programmers might include assert() statements in their application to
126** verify that values returned by these interfaces match the macros in
127** the header, and thus ensure that the application is
128** compiled with matching library and header files.
129**
130** <blockquote><pre>
131** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
132** assert( strcmp(sqlite3_sourceid(),SQLITE_SOURCE_ID)==0 );
133** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
134** </pre></blockquote>)^
135**
136** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
137** macro. ^The sqlite3_libversion() function returns a pointer to the
138** to the sqlite3_version[] string constant. The sqlite3_libversion()
139** function is provided for use in DLLs since DLL users usually do not have
140** direct access to string constants within the DLL. ^The
141** sqlite3_libversion_number() function returns an integer equal to
142** [SQLITE_VERSION_NUMBER]. ^The sqlite3_sourceid() function returns
143** a pointer to a string constant whose value is the same as the
144** [SQLITE_SOURCE_ID] C preprocessor macro.
145**
146** See also: [sqlite_version()] and [sqlite_source_id()].
147*/
148SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
149SQLITE_API const char *SQLITE_STDCALL sqlite3_libversion(void);
150SQLITE_API const char *SQLITE_STDCALL sqlite3_sourceid(void);
151SQLITE_API int SQLITE_STDCALL sqlite3_libversion_number(void);
152
153/*
154** CAPI3REF: Run-Time Library Compilation Options Diagnostics
155**
156** ^The sqlite3_compileoption_used() function returns 0 or 1
157** indicating whether the specified option was defined at
158** compile time. ^The SQLITE_ prefix may be omitted from the
159** option name passed to sqlite3_compileoption_used().
160**
161** ^The sqlite3_compileoption_get() function allows iterating
162** over the list of options that were defined at compile time by
163** returning the N-th compile time option string. ^If N is out of range,
164** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
165** prefix is omitted from any strings returned by
166** sqlite3_compileoption_get().
167**
168** ^Support for the diagnostic functions sqlite3_compileoption_used()
169** and sqlite3_compileoption_get() may be omitted by specifying the
170** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
171**
172** See also: SQL functions [sqlite_compileoption_used()] and
173** [sqlite_compileoption_get()] and the [compile_options pragma].
174*/
175#ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
176SQLITE_API int SQLITE_STDCALL sqlite3_compileoption_used(const char *zOptName);
177SQLITE_API const char *SQLITE_STDCALL sqlite3_compileoption_get(int N);
178#endif
179
180/*
181** CAPI3REF: Test To See If The Library Is Threadsafe
182**
183** ^The sqlite3_threadsafe() function returns zero if and only if
184** SQLite was compiled with mutexing code omitted due to the
185** [SQLITE_THREADSAFE] compile-time option being set to 0.
186**
187** SQLite can be compiled with or without mutexes. When
188** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
189** are enabled and SQLite is threadsafe. When the
190** [SQLITE_THREADSAFE] macro is 0,
191** the mutexes are omitted. Without the mutexes, it is not safe
192** to use SQLite concurrently from more than one thread.
193**
194** Enabling mutexes incurs a measurable performance penalty.
195** So if speed is of utmost importance, it makes sense to disable
196** the mutexes. But for maximum safety, mutexes should be enabled.
197** ^The default behavior is for mutexes to be enabled.
198**
199** This interface can be used by an application to make sure that the
200** version of SQLite that it is linking against was compiled with
201** the desired setting of the [SQLITE_THREADSAFE] macro.
202**
203** This interface only reports on the compile-time mutex setting
204** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
205** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
206** can be fully or partially disabled using a call to [sqlite3_config()]
207** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
208** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
209** sqlite3_threadsafe() function shows only the compile-time setting of
210** thread safety, not any run-time changes to that setting made by
211** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
212** is unchanged by calls to sqlite3_config().)^
213**
214** See the [threading mode] documentation for additional information.
215*/
216SQLITE_API int SQLITE_STDCALL sqlite3_threadsafe(void);
217
218/*
219** CAPI3REF: Database Connection Handle
220** KEYWORDS: {database connection} {database connections}
221**
222** Each open SQLite database is represented by a pointer to an instance of
223** the opaque structure named "sqlite3". It is useful to think of an sqlite3
224** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
225** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
226** and [sqlite3_close_v2()] are its destructors. There are many other
227** interfaces (such as
228** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
229** [sqlite3_busy_timeout()] to name but three) that are methods on an
230** sqlite3 object.
231*/
232typedef struct sqlite3 sqlite3;
233
234/*
235** CAPI3REF: 64-Bit Integer Types
236** KEYWORDS: sqlite_int64 sqlite_uint64
237**
238** Because there is no cross-platform way to specify 64-bit integer types
239** SQLite includes typedefs for 64-bit signed and unsigned integers.
240**
241** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
242** The sqlite_int64 and sqlite_uint64 types are supported for backwards
243** compatibility only.
244**
245** ^The sqlite3_int64 and sqlite_int64 types can store integer values
246** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
247** sqlite3_uint64 and sqlite_uint64 types can store integer values
248** between 0 and +18446744073709551615 inclusive.
249*/
250#ifdef SQLITE_INT64_TYPE
251 typedef SQLITE_INT64_TYPE sqlite_int64;
252 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
253#elif defined(_MSC_VER) || defined(__BORLANDC__)
254 typedef __int64 sqlite_int64;
255 typedef unsigned __int64 sqlite_uint64;
256#else
257 typedef long long int sqlite_int64;
258 typedef unsigned long long int sqlite_uint64;
259#endif
260typedef sqlite_int64 sqlite3_int64;
261typedef sqlite_uint64 sqlite3_uint64;
262
263/*
264** If compiling for a processor that lacks floating point support,
265** substitute integer for floating-point.
266*/
267#ifdef SQLITE_OMIT_FLOATING_POINT
268# define double sqlite3_int64
269#endif
270
271/*
272** CAPI3REF: Closing A Database Connection
273** DESTRUCTOR: sqlite3
274**
275** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
276** for the [sqlite3] object.
277** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
278** the [sqlite3] object is successfully destroyed and all associated
279** resources are deallocated.
280**
281** ^If the database connection is associated with unfinalized prepared
282** statements or unfinished sqlite3_backup objects then sqlite3_close()
283** will leave the database connection open and return [SQLITE_BUSY].
284** ^If sqlite3_close_v2() is called with unfinalized prepared statements
285** and/or unfinished sqlite3_backups, then the database connection becomes
286** an unusable "zombie" which will automatically be deallocated when the
287** last prepared statement is finalized or the last sqlite3_backup is
288** finished. The sqlite3_close_v2() interface is intended for use with
289** host languages that are garbage collected, and where the order in which
290** destructors are called is arbitrary.
291**
292** Applications should [sqlite3_finalize | finalize] all [prepared statements],
293** [sqlite3_blob_close | close] all [BLOB handles], and
294** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
295** with the [sqlite3] object prior to attempting to close the object. ^If
296** sqlite3_close_v2() is called on a [database connection] that still has
297** outstanding [prepared statements], [BLOB handles], and/or
298** [sqlite3_backup] objects then it returns [SQLITE_OK] and the deallocation
299** of resources is deferred until all [prepared statements], [BLOB handles],
300** and [sqlite3_backup] objects are also destroyed.
301**
302** ^If an [sqlite3] object is destroyed while a transaction is open,
303** the transaction is automatically rolled back.
304**
305** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
306** must be either a NULL
307** pointer or an [sqlite3] object pointer obtained
308** from [sqlite3_open()], [sqlite3_open16()], or
309** [sqlite3_open_v2()], and not previously closed.
310** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
311** argument is a harmless no-op.
312*/
313SQLITE_API int SQLITE_STDCALL sqlite3_close(sqlite3*);
314SQLITE_API int SQLITE_STDCALL sqlite3_close_v2(sqlite3*);
315
316/*
317** The type for a callback function.
318** This is legacy and deprecated. It is included for historical
319** compatibility and is not documented.
320*/
321typedef int (*sqlite3_callback)(void*,int,char**, char**);
322
323/*
324** CAPI3REF: One-Step Query Execution Interface
325** METHOD: sqlite3
326**
327** The sqlite3_exec() interface is a convenience wrapper around
328** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
329** that allows an application to run multiple statements of SQL
330** without having to use a lot of C code.
331**
332** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
333** semicolon-separate SQL statements passed into its 2nd argument,
334** in the context of the [database connection] passed in as its 1st
335** argument. ^If the callback function of the 3rd argument to
336** sqlite3_exec() is not NULL, then it is invoked for each result row
337** coming out of the evaluated SQL statements. ^The 4th argument to
338** sqlite3_exec() is relayed through to the 1st argument of each
339** callback invocation. ^If the callback pointer to sqlite3_exec()
340** is NULL, then no callback is ever invoked and result rows are
341** ignored.
342**
343** ^If an error occurs while evaluating the SQL statements passed into
344** sqlite3_exec(), then execution of the current statement stops and
345** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
346** is not NULL then any error message is written into memory obtained
347** from [sqlite3_malloc()] and passed back through the 5th parameter.
348** To avoid memory leaks, the application should invoke [sqlite3_free()]
349** on error message strings returned through the 5th parameter of
350** sqlite3_exec() after the error message string is no longer needed.
351** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
352** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
353** NULL before returning.
354**
355** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
356** routine returns SQLITE_ABORT without invoking the callback again and
357** without running any subsequent SQL statements.
358**
359** ^The 2nd argument to the sqlite3_exec() callback function is the
360** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
361** callback is an array of pointers to strings obtained as if from
362** [sqlite3_column_text()], one for each column. ^If an element of a
363** result row is NULL then the corresponding string pointer for the
364** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
365** sqlite3_exec() callback is an array of pointers to strings where each
366** entry represents the name of corresponding result column as obtained
367** from [sqlite3_column_name()].
368**
369** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
370** to an empty string, or a pointer that contains only whitespace and/or
371** SQL comments, then no SQL statements are evaluated and the database
372** is not changed.
373**
374** Restrictions:
375**
376** <ul>
377** <li> The application must ensure that the 1st parameter to sqlite3_exec()
378** is a valid and open [database connection].
379** <li> The application must not close the [database connection] specified by
380** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
381** <li> The application must not modify the SQL statement text passed into
382** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
383** </ul>
384*/
385SQLITE_API int SQLITE_STDCALL sqlite3_exec(
386 sqlite3*, /* An open database */
387 const char *sql, /* SQL to be evaluated */
388 int (*callback)(void*,int,char**,char**), /* Callback function */
389 void *, /* 1st argument to callback */
390 char **errmsg /* Error msg written here */
391);
392
393/*
394** CAPI3REF: Result Codes
395** KEYWORDS: {result code definitions}
396**
397** Many SQLite functions return an integer result code from the set shown
398** here in order to indicate success or failure.
399**
400** New error codes may be added in future versions of SQLite.
401**
402** See also: [extended result code definitions]
403*/
404#define SQLITE_OK 0 /* Successful result */
405/* beginning-of-error-codes */
406#define SQLITE_ERROR 1 /* SQL error or missing database */
407#define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
408#define SQLITE_PERM 3 /* Access permission denied */
409#define SQLITE_ABORT 4 /* Callback routine requested an abort */
410#define SQLITE_BUSY 5 /* The database file is locked */
411#define SQLITE_LOCKED 6 /* A table in the database is locked */
412#define SQLITE_NOMEM 7 /* A malloc() failed */
413#define SQLITE_READONLY 8 /* Attempt to write a readonly database */
414#define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
415#define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
416#define SQLITE_CORRUPT 11 /* The database disk image is malformed */
417#define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
418#define SQLITE_FULL 13 /* Insertion failed because database is full */
419#define SQLITE_CANTOPEN 14 /* Unable to open the database file */
420#define SQLITE_PROTOCOL 15 /* Database lock protocol error */
421#define SQLITE_EMPTY 16 /* Database is empty */
422#define SQLITE_SCHEMA 17 /* The database schema changed */
423#define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
424#define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
425#define SQLITE_MISMATCH 20 /* Data type mismatch */
426#define SQLITE_MISUSE 21 /* Library used incorrectly */
427#define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
428#define SQLITE_AUTH 23 /* Authorization denied */
429#define SQLITE_FORMAT 24 /* Auxiliary database format error */
430#define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
431#define SQLITE_NOTADB 26 /* File opened that is not a database file */
432#define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
433#define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
434#define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
435#define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
436/* end-of-error-codes */
437
438/*
439** CAPI3REF: Extended Result Codes
440** KEYWORDS: {extended result code definitions}
441**
442** In its default configuration, SQLite API routines return one of 30 integer
443** [result codes]. However, experience has shown that many of
444** these result codes are too coarse-grained. They do not provide as
445** much information about problems as programmers might like. In an effort to
446** address this, newer versions of SQLite (version 3.3.8 and later) include
447** support for additional result codes that provide more detailed information
448** about errors. These [extended result codes] are enabled or disabled
449** on a per database connection basis using the
450** [sqlite3_extended_result_codes()] API. Or, the extended code for
451** the most recent error can be obtained using
452** [sqlite3_extended_errcode()].
453*/
454#define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
455#define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
456#define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
457#define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
458#define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
459#define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
460#define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
461#define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
462#define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
463#define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
464#define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
465#define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
466#define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
467#define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
468#define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
469#define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
470#define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
471#define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
472#define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
473#define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
474#define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
475#define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
476#define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
477#define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
478#define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
479#define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
480#define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
481#define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
482#define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
483#define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
484#define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
485#define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
486#define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
487#define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
488#define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
489#define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
490#define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
491#define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
492#define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
493#define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
494#define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
495#define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
496#define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
497#define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
498#define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
499#define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
500#define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
501#define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
502#define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
503#define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
504#define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
505#define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
506#define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
507#define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
508#define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
509
510/*
511** CAPI3REF: Flags For File Open Operations
512**
513** These bit values are intended for use in the
514** 3rd parameter to the [sqlite3_open_v2()] interface and
515** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
516*/
517#define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
518#define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
519#define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
520#define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
521#define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
522#define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
523#define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
524#define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
525#define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
526#define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
527#define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
528#define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
529#define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
530#define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
531#define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
532#define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
533#define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
534#define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
535#define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
536#define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
537
538/* Reserved: 0x00F00000 */
539
540/*
541** CAPI3REF: Device Characteristics
542**
543** The xDeviceCharacteristics method of the [sqlite3_io_methods]
544** object returns an integer which is a vector of these
545** bit values expressing I/O characteristics of the mass storage
546** device that holds the file that the [sqlite3_io_methods]
547** refers to.
548**
549** The SQLITE_IOCAP_ATOMIC property means that all writes of
550** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
551** mean that writes of blocks that are nnn bytes in size and
552** are aligned to an address which is an integer multiple of
553** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
554** that when data is appended to a file, the data is appended
555** first then the size of the file is extended, never the other
556** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
557** information is written to disk in the same order as calls
558** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
559** after reboot following a crash or power loss, the only bytes in a
560** file that were written at the application level might have changed
561** and that adjacent bytes, even bytes within the same sector are
562** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
563** flag indicate that a file cannot be deleted when open. The
564** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
565** read-only media and cannot be changed even by processes with
566** elevated privileges.
567*/
568#define SQLITE_IOCAP_ATOMIC 0x00000001
569#define SQLITE_IOCAP_ATOMIC512 0x00000002
570#define SQLITE_IOCAP_ATOMIC1K 0x00000004
571#define SQLITE_IOCAP_ATOMIC2K 0x00000008
572#define SQLITE_IOCAP_ATOMIC4K 0x00000010
573#define SQLITE_IOCAP_ATOMIC8K 0x00000020
574#define SQLITE_IOCAP_ATOMIC16K 0x00000040
575#define SQLITE_IOCAP_ATOMIC32K 0x00000080
576#define SQLITE_IOCAP_ATOMIC64K 0x00000100
577#define SQLITE_IOCAP_SAFE_APPEND 0x00000200
578#define SQLITE_IOCAP_SEQUENTIAL 0x00000400
579#define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
580#define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
581#define SQLITE_IOCAP_IMMUTABLE 0x00002000
582
583/*
584** CAPI3REF: File Locking Levels
585**
586** SQLite uses one of these integer values as the second
587** argument to calls it makes to the xLock() and xUnlock() methods
588** of an [sqlite3_io_methods] object.
589*/
590#define SQLITE_LOCK_NONE 0
591#define SQLITE_LOCK_SHARED 1
592#define SQLITE_LOCK_RESERVED 2
593#define SQLITE_LOCK_PENDING 3
594#define SQLITE_LOCK_EXCLUSIVE 4
595
596/*
597** CAPI3REF: Synchronization Type Flags
598**
599** When SQLite invokes the xSync() method of an
600** [sqlite3_io_methods] object it uses a combination of
601** these integer values as the second argument.
602**
603** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
604** sync operation only needs to flush data to mass storage. Inode
605** information need not be flushed. If the lower four bits of the flag
606** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
607** If the lower four bits equal SQLITE_SYNC_FULL, that means
608** to use Mac OS X style fullsync instead of fsync().
609**
610** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
611** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
612** settings. The [synchronous pragma] determines when calls to the
613** xSync VFS method occur and applies uniformly across all platforms.
614** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
615** energetic or rigorous or forceful the sync operations are and
616** only make a difference on Mac OSX for the default SQLite code.
617** (Third-party VFS implementations might also make the distinction
618** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
619** operating systems natively supported by SQLite, only Mac OSX
620** cares about the difference.)
621*/
622#define SQLITE_SYNC_NORMAL 0x00002
623#define SQLITE_SYNC_FULL 0x00003
624#define SQLITE_SYNC_DATAONLY 0x00010
625
626/*
627** CAPI3REF: OS Interface Open File Handle
628**
629** An [sqlite3_file] object represents an open file in the
630** [sqlite3_vfs | OS interface layer]. Individual OS interface
631** implementations will
632** want to subclass this object by appending additional fields
633** for their own use. The pMethods entry is a pointer to an
634** [sqlite3_io_methods] object that defines methods for performing
635** I/O operations on the open file.
636*/
637typedef struct sqlite3_file sqlite3_file;
638struct sqlite3_file {
639 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
640};
641
642/*
643** CAPI3REF: OS Interface File Virtual Methods Object
644**
645** Every file opened by the [sqlite3_vfs.xOpen] method populates an
646** [sqlite3_file] object (or, more commonly, a subclass of the
647** [sqlite3_file] object) with a pointer to an instance of this object.
648** This object defines the methods used to perform various operations
649** against the open file represented by the [sqlite3_file] object.
650**
651** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
652** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
653** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
654** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
655** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
656** to NULL.
657**
658** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
659** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
660** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
661** flag may be ORed in to indicate that only the data of the file
662** and not its inode needs to be synced.
663**
664** The integer values to xLock() and xUnlock() are one of
665** <ul>
666** <li> [SQLITE_LOCK_NONE],
667** <li> [SQLITE_LOCK_SHARED],
668** <li> [SQLITE_LOCK_RESERVED],
669** <li> [SQLITE_LOCK_PENDING], or
670** <li> [SQLITE_LOCK_EXCLUSIVE].
671** </ul>
672** xLock() increases the lock. xUnlock() decreases the lock.
673** The xCheckReservedLock() method checks whether any database connection,
674** either in this process or in some other process, is holding a RESERVED,
675** PENDING, or EXCLUSIVE lock on the file. It returns true
676** if such a lock exists and false otherwise.
677**
678** The xFileControl() method is a generic interface that allows custom
679** VFS implementations to directly control an open file using the
680** [sqlite3_file_control()] interface. The second "op" argument is an
681** integer opcode. The third argument is a generic pointer intended to
682** point to a structure that may contain arguments or space in which to
683** write return values. Potential uses for xFileControl() might be
684** functions to enable blocking locks with timeouts, to change the
685** locking strategy (for example to use dot-file locks), to inquire
686** about the status of a lock, or to break stale locks. The SQLite
687** core reserves all opcodes less than 100 for its own use.
688** A [file control opcodes | list of opcodes] less than 100 is available.
689** Applications that define a custom xFileControl method should use opcodes
690** greater than 100 to avoid conflicts. VFS implementations should
691** return [SQLITE_NOTFOUND] for file control opcodes that they do not
692** recognize.
693**
694** The xSectorSize() method returns the sector size of the
695** device that underlies the file. The sector size is the
696** minimum write that can be performed without disturbing
697** other bytes in the file. The xDeviceCharacteristics()
698** method returns a bit vector describing behaviors of the
699** underlying device:
700**
701** <ul>
702** <li> [SQLITE_IOCAP_ATOMIC]
703** <li> [SQLITE_IOCAP_ATOMIC512]
704** <li> [SQLITE_IOCAP_ATOMIC1K]
705** <li> [SQLITE_IOCAP_ATOMIC2K]
706** <li> [SQLITE_IOCAP_ATOMIC4K]
707** <li> [SQLITE_IOCAP_ATOMIC8K]
708** <li> [SQLITE_IOCAP_ATOMIC16K]
709** <li> [SQLITE_IOCAP_ATOMIC32K]
710** <li> [SQLITE_IOCAP_ATOMIC64K]
711** <li> [SQLITE_IOCAP_SAFE_APPEND]
712** <li> [SQLITE_IOCAP_SEQUENTIAL]
713** </ul>
714**
715** The SQLITE_IOCAP_ATOMIC property means that all writes of
716** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
717** mean that writes of blocks that are nnn bytes in size and
718** are aligned to an address which is an integer multiple of
719** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
720** that when data is appended to a file, the data is appended
721** first then the size of the file is extended, never the other
722** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
723** information is written to disk in the same order as calls
724** to xWrite().
725**
726** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
727** in the unread portions of the buffer with zeros. A VFS that
728** fails to zero-fill short reads might seem to work. However,
729** failure to zero-fill short reads will eventually lead to
730** database corruption.
731*/
732typedef struct sqlite3_io_methods sqlite3_io_methods;
733struct sqlite3_io_methods {
734 int iVersion;
735 int (*xClose)(sqlite3_file*);
736 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
737 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
738 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
739 int (*xSync)(sqlite3_file*, int flags);
740 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
741 int (*xLock)(sqlite3_file*, int);
742 int (*xUnlock)(sqlite3_file*, int);
743 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
744 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
745 int (*xSectorSize)(sqlite3_file*);
746 int (*xDeviceCharacteristics)(sqlite3_file*);
747 /* Methods above are valid for version 1 */
748 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
749 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
750 void (*xShmBarrier)(sqlite3_file*);
751 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
752 /* Methods above are valid for version 2 */
753 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
754 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
755 /* Methods above are valid for version 3 */
756 /* Additional methods may be added in future releases */
757};
758
759/*
760** CAPI3REF: Standard File Control Opcodes
761** KEYWORDS: {file control opcodes} {file control opcode}
762**
763** These integer constants are opcodes for the xFileControl method
764** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
765** interface.
766**
767** <ul>
768** <li>[[SQLITE_FCNTL_LOCKSTATE]]
769** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
770** opcode causes the xFileControl method to write the current state of
771** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
772** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
773** into an integer that the pArg argument points to. This capability
774** is used during testing and is only available when the SQLITE_TEST
775** compile-time option is used.
776**
777** <li>[[SQLITE_FCNTL_SIZE_HINT]]
778** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
779** layer a hint of how large the database file will grow to be during the
780** current transaction. This hint is not guaranteed to be accurate but it
781** is often close. The underlying VFS might choose to preallocate database
782** file space based on this hint in order to help writes to the database
783** file run faster.
784**
785** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
786** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
787** extends and truncates the database file in chunks of a size specified
788** by the user. The fourth argument to [sqlite3_file_control()] should
789** point to an integer (type int) containing the new chunk-size to use
790** for the nominated database. Allocating database file space in large
791** chunks (say 1MB at a time), may reduce file-system fragmentation and
792** improve performance on some systems.
793**
794** <li>[[SQLITE_FCNTL_FILE_POINTER]]
795** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
796** to the [sqlite3_file] object associated with a particular database
797** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
798**
799** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
800** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
801** to the [sqlite3_file] object associated with the journal file (either
802** the [rollback journal] or the [write-ahead log]) for a particular database
803** connection. See also [SQLITE_FCNTL_FILE_POINTER].
804**
805** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
806** No longer in use.
807**
808** <li>[[SQLITE_FCNTL_SYNC]]
809** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
810** sent to the VFS immediately before the xSync method is invoked on a
811** database file descriptor. Or, if the xSync method is not invoked
812** because the user has configured SQLite with
813** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
814** of the xSync method. In most cases, the pointer argument passed with
815** this file-control is NULL. However, if the database file is being synced
816** as part of a multi-database commit, the argument points to a nul-terminated
817** string containing the transactions master-journal file name. VFSes that
818** do not need this signal should silently ignore this opcode. Applications
819** should not call [sqlite3_file_control()] with this opcode as doing so may
820** disrupt the operation of the specialized VFSes that do require it.
821**
822** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
823** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
824** and sent to the VFS after a transaction has been committed immediately
825** but before the database is unlocked. VFSes that do not need this signal
826** should silently ignore this opcode. Applications should not call
827** [sqlite3_file_control()] with this opcode as doing so may disrupt the
828** operation of the specialized VFSes that do require it.
829**
830** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
831** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
832** retry counts and intervals for certain disk I/O operations for the
833** windows [VFS] in order to provide robustness in the presence of
834** anti-virus programs. By default, the windows VFS will retry file read,
835** file write, and file delete operations up to 10 times, with a delay
836** of 25 milliseconds before the first retry and with the delay increasing
837** by an additional 25 milliseconds with each subsequent retry. This
838** opcode allows these two values (10 retries and 25 milliseconds of delay)
839** to be adjusted. The values are changed for all database connections
840** within the same process. The argument is a pointer to an array of two
841** integers where the first integer i the new retry count and the second
842** integer is the delay. If either integer is negative, then the setting
843** is not changed but instead the prior value of that setting is written
844** into the array entry, allowing the current retry settings to be
845** interrogated. The zDbName parameter is ignored.
846**
847** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
848** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
849** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
850** write ahead log and shared memory files used for transaction control
851** are automatically deleted when the latest connection to the database
852** closes. Setting persistent WAL mode causes those files to persist after
853** close. Persisting the files is useful when other processes that do not
854** have write permission on the directory containing the database file want
855** to read the database file, as the WAL and shared memory files must exist
856** in order for the database to be readable. The fourth parameter to
857** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
858** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
859** WAL mode. If the integer is -1, then it is overwritten with the current
860** WAL persistence setting.
861**
862** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
863** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
864** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
865** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
866** xDeviceCharacteristics methods. The fourth parameter to
867** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
868** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
869** mode. If the integer is -1, then it is overwritten with the current
870** zero-damage mode setting.
871**
872** <li>[[SQLITE_FCNTL_OVERWRITE]]
873** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
874** a write transaction to indicate that, unless it is rolled back for some
875** reason, the entire database file will be overwritten by the current
876** transaction. This is used by VACUUM operations.
877**
878** <li>[[SQLITE_FCNTL_VFSNAME]]
879** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
880** all [VFSes] in the VFS stack. The names are of all VFS shims and the
881** final bottom-level VFS are written into memory obtained from
882** [sqlite3_malloc()] and the result is stored in the char* variable
883** that the fourth parameter of [sqlite3_file_control()] points to.
884** The caller is responsible for freeing the memory when done. As with
885** all file-control actions, there is no guarantee that this will actually
886** do anything. Callers should initialize the char* variable to a NULL
887** pointer in case this file-control is not implemented. This file-control
888** is intended for diagnostic use only.
889**
890** <li>[[SQLITE_FCNTL_VFS_POINTER]]
891** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
892** [VFSes] currently in use. ^(The argument X in
893** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
894** of type "[sqlite3_vfs] **". This opcodes will set *X
895** to a pointer to the top-level VFS.)^
896** ^When there are multiple VFS shims in the stack, this opcode finds the
897** upper-most shim only.
898**
899** <li>[[SQLITE_FCNTL_PRAGMA]]
900** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
901** file control is sent to the open [sqlite3_file] object corresponding
902** to the database file to which the pragma statement refers. ^The argument
903** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
904** pointers to strings (char**) in which the second element of the array
905** is the name of the pragma and the third element is the argument to the
906** pragma or NULL if the pragma has no argument. ^The handler for an
907** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
908** of the char** argument point to a string obtained from [sqlite3_mprintf()]
909** or the equivalent and that string will become the result of the pragma or
910** the error message if the pragma fails. ^If the
911** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
912** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
913** file control returns [SQLITE_OK], then the parser assumes that the
914** VFS has handled the PRAGMA itself and the parser generates a no-op
915** prepared statement if result string is NULL, or that returns a copy
916** of the result string if the string is non-NULL.
917** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
918** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
919** that the VFS encountered an error while handling the [PRAGMA] and the
920** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
921** file control occurs at the beginning of pragma statement analysis and so
922** it is able to override built-in [PRAGMA] statements.
923**
924** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
925** ^The [SQLITE_FCNTL_BUSYHANDLER]
926** file-control may be invoked by SQLite on the database file handle
927** shortly after it is opened in order to provide a custom VFS with access
928** to the connections busy-handler callback. The argument is of type (void **)
929** - an array of two (void *) values. The first (void *) actually points
930** to a function of type (int (*)(void *)). In order to invoke the connections
931** busy-handler, this function should be invoked with the second (void *) in
932** the array as the only argument. If it returns non-zero, then the operation
933** should be retried. If it returns zero, the custom VFS should abandon the
934** current operation.
935**
936** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
937** ^Application can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
938** to have SQLite generate a
939** temporary filename using the same algorithm that is followed to generate
940** temporary filenames for TEMP tables and other internal uses. The
941** argument should be a char** which will be filled with the filename
942** written into memory obtained from [sqlite3_malloc()]. The caller should
943** invoke [sqlite3_free()] on the result to avoid a memory leak.
944**
945** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
946** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
947** maximum number of bytes that will be used for memory-mapped I/O.
948** The argument is a pointer to a value of type sqlite3_int64 that
949** is an advisory maximum number of bytes in the file to memory map. The
950** pointer is overwritten with the old value. The limit is not changed if
951** the value originally pointed to is negative, and so the current limit
952** can be queried by passing in a pointer to a negative number. This
953** file-control is used internally to implement [PRAGMA mmap_size].
954**
955** <li>[[SQLITE_FCNTL_TRACE]]
956** The [SQLITE_FCNTL_TRACE] file control provides advisory information
957** to the VFS about what the higher layers of the SQLite stack are doing.
958** This file control is used by some VFS activity tracing [shims].
959** The argument is a zero-terminated string. Higher layers in the
960** SQLite stack may generate instances of this file control if
961** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
962**
963** <li>[[SQLITE_FCNTL_HAS_MOVED]]
964** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
965** pointer to an integer and it writes a boolean into that integer depending
966** on whether or not the file has been renamed, moved, or deleted since it
967** was first opened.
968**
969** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
970** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
971** opcode causes the xFileControl method to swap the file handle with the one
972** pointed to by the pArg argument. This capability is used during testing
973** and only needs to be supported when SQLITE_TEST is defined.
974**
975** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
976** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
977** be advantageous to block on the next WAL lock if the lock is not immediately
978** available. The WAL subsystem issues this signal during rare
979** circumstances in order to fix a problem with priority inversion.
980** Applications should <em>not</em> use this file-control.
981**
982** <li>[[SQLITE_FCNTL_ZIPVFS]]
983** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
984** VFS should return SQLITE_NOTFOUND for this opcode.
985**
986** <li>[[SQLITE_FCNTL_RBU]]
987** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
988** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
989** this opcode.
990** </ul>
991*/
992#define SQLITE_FCNTL_LOCKSTATE 1
993#define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
994#define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
995#define SQLITE_FCNTL_LAST_ERRNO 4
996#define SQLITE_FCNTL_SIZE_HINT 5
997#define SQLITE_FCNTL_CHUNK_SIZE 6
998#define SQLITE_FCNTL_FILE_POINTER 7
999#define SQLITE_FCNTL_SYNC_OMITTED 8
1000#define SQLITE_FCNTL_WIN32_AV_RETRY 9
1001#define SQLITE_FCNTL_PERSIST_WAL 10
1002#define SQLITE_FCNTL_OVERWRITE 11
1003#define SQLITE_FCNTL_VFSNAME 12
1004#define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1005#define SQLITE_FCNTL_PRAGMA 14
1006#define SQLITE_FCNTL_BUSYHANDLER 15
1007#define SQLITE_FCNTL_TEMPFILENAME 16
1008#define SQLITE_FCNTL_MMAP_SIZE 18
1009#define SQLITE_FCNTL_TRACE 19
1010#define SQLITE_FCNTL_HAS_MOVED 20
1011#define SQLITE_FCNTL_SYNC 21
1012#define SQLITE_FCNTL_COMMIT_PHASETWO 22
1013#define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1014#define SQLITE_FCNTL_WAL_BLOCK 24
1015#define SQLITE_FCNTL_ZIPVFS 25
1016#define SQLITE_FCNTL_RBU 26
1017#define SQLITE_FCNTL_VFS_POINTER 27
1018#define SQLITE_FCNTL_JOURNAL_POINTER 28
1019
1020/* deprecated names */
1021#define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1022#define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1023#define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1024
1025
1026/*
1027** CAPI3REF: Mutex Handle
1028**
1029** The mutex module within SQLite defines [sqlite3_mutex] to be an
1030** abstract type for a mutex object. The SQLite core never looks
1031** at the internal representation of an [sqlite3_mutex]. It only
1032** deals with pointers to the [sqlite3_mutex] object.
1033**
1034** Mutexes are created using [sqlite3_mutex_alloc()].
1035*/
1036typedef struct sqlite3_mutex sqlite3_mutex;
1037
1038/*
1039** CAPI3REF: OS Interface Object
1040**
1041** An instance of the sqlite3_vfs object defines the interface between
1042** the SQLite core and the underlying operating system. The "vfs"
1043** in the name of the object stands for "virtual file system". See
1044** the [VFS | VFS documentation] for further information.
1045**
1046** The value of the iVersion field is initially 1 but may be larger in
1047** future versions of SQLite. Additional fields may be appended to this
1048** object when the iVersion value is increased. Note that the structure
1049** of the sqlite3_vfs object changes in the transaction between
1050** SQLite version 3.5.9 and 3.6.0 and yet the iVersion field was not
1051** modified.
1052**
1053** The szOsFile field is the size of the subclassed [sqlite3_file]
1054** structure used by this VFS. mxPathname is the maximum length of
1055** a pathname in this VFS.
1056**
1057** Registered sqlite3_vfs objects are kept on a linked list formed by
1058** the pNext pointer. The [sqlite3_vfs_register()]
1059** and [sqlite3_vfs_unregister()] interfaces manage this list
1060** in a thread-safe way. The [sqlite3_vfs_find()] interface
1061** searches the list. Neither the application code nor the VFS
1062** implementation should use the pNext pointer.
1063**
1064** The pNext field is the only field in the sqlite3_vfs
1065** structure that SQLite will ever modify. SQLite will only access
1066** or modify this field while holding a particular static mutex.
1067** The application should never modify anything within the sqlite3_vfs
1068** object once the object has been registered.
1069**
1070** The zName field holds the name of the VFS module. The name must
1071** be unique across all VFS modules.
1072**
1073** [[sqlite3_vfs.xOpen]]
1074** ^SQLite guarantees that the zFilename parameter to xOpen
1075** is either a NULL pointer or string obtained
1076** from xFullPathname() with an optional suffix added.
1077** ^If a suffix is added to the zFilename parameter, it will
1078** consist of a single "-" character followed by no more than
1079** 11 alphanumeric and/or "-" characters.
1080** ^SQLite further guarantees that
1081** the string will be valid and unchanged until xClose() is
1082** called. Because of the previous sentence,
1083** the [sqlite3_file] can safely store a pointer to the
1084** filename if it needs to remember the filename for some reason.
1085** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1086** must invent its own temporary name for the file. ^Whenever the
1087** xFilename parameter is NULL it will also be the case that the
1088** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1089**
1090** The flags argument to xOpen() includes all bits set in
1091** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1092** or [sqlite3_open16()] is used, then flags includes at least
1093** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1094** If xOpen() opens a file read-only then it sets *pOutFlags to
1095** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1096**
1097** ^(SQLite will also add one of the following flags to the xOpen()
1098** call, depending on the object being opened:
1099**
1100** <ul>
1101** <li> [SQLITE_OPEN_MAIN_DB]
1102** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1103** <li> [SQLITE_OPEN_TEMP_DB]
1104** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1105** <li> [SQLITE_OPEN_TRANSIENT_DB]
1106** <li> [SQLITE_OPEN_SUBJOURNAL]
1107** <li> [SQLITE_OPEN_MASTER_JOURNAL]
1108** <li> [SQLITE_OPEN_WAL]
1109** </ul>)^
1110**
1111** The file I/O implementation can use the object type flags to
1112** change the way it deals with files. For example, an application
1113** that does not care about crash recovery or rollback might make
1114** the open of a journal file a no-op. Writes to this journal would
1115** also be no-ops, and any attempt to read the journal would return
1116** SQLITE_IOERR. Or the implementation might recognize that a database
1117** file will be doing page-aligned sector reads and writes in a random
1118** order and set up its I/O subsystem accordingly.
1119**
1120** SQLite might also add one of the following flags to the xOpen method:
1121**
1122** <ul>
1123** <li> [SQLITE_OPEN_DELETEONCLOSE]
1124** <li> [SQLITE_OPEN_EXCLUSIVE]
1125** </ul>
1126**
1127** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1128** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1129** will be set for TEMP databases and their journals, transient
1130** databases, and subjournals.
1131**
1132** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1133** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1134** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1135** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1136** SQLITE_OPEN_CREATE, is used to indicate that file should always
1137** be created, and that it is an error if it already exists.
1138** It is <i>not</i> used to indicate the file should be opened
1139** for exclusive access.
1140**
1141** ^At least szOsFile bytes of memory are allocated by SQLite
1142** to hold the [sqlite3_file] structure passed as the third
1143** argument to xOpen. The xOpen method does not have to
1144** allocate the structure; it should just fill it in. Note that
1145** the xOpen method must set the sqlite3_file.pMethods to either
1146** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1147** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1148** element will be valid after xOpen returns regardless of the success
1149** or failure of the xOpen call.
1150**
1151** [[sqlite3_vfs.xAccess]]
1152** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1153** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1154** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1155** to test whether a file is at least readable. The file can be a
1156** directory.
1157**
1158** ^SQLite will always allocate at least mxPathname+1 bytes for the
1159** output buffer xFullPathname. The exact size of the output buffer
1160** is also passed as a parameter to both methods. If the output buffer
1161** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1162** handled as a fatal error by SQLite, vfs implementations should endeavor
1163** to prevent this by setting mxPathname to a sufficiently large value.
1164**
1165** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1166** interfaces are not strictly a part of the filesystem, but they are
1167** included in the VFS structure for completeness.
1168** The xRandomness() function attempts to return nBytes bytes
1169** of good-quality randomness into zOut. The return value is
1170** the actual number of bytes of randomness obtained.
1171** The xSleep() method causes the calling thread to sleep for at
1172** least the number of microseconds given. ^The xCurrentTime()
1173** method returns a Julian Day Number for the current date and time as
1174** a floating point value.
1175** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1176** Day Number multiplied by 86400000 (the number of milliseconds in
1177** a 24-hour day).
1178** ^SQLite will use the xCurrentTimeInt64() method to get the current
1179** date and time if that method is available (if iVersion is 2 or
1180** greater and the function pointer is not NULL) and will fall back
1181** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1182**
1183** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1184** are not used by the SQLite core. These optional interfaces are provided
1185** by some VFSes to facilitate testing of the VFS code. By overriding
1186** system calls with functions under its control, a test program can
1187** simulate faults and error conditions that would otherwise be difficult
1188** or impossible to induce. The set of system calls that can be overridden
1189** varies from one VFS to another, and from one version of the same VFS to the
1190** next. Applications that use these interfaces must be prepared for any
1191** or all of these interfaces to be NULL or for their behavior to change
1192** from one release to the next. Applications must not attempt to access
1193** any of these methods if the iVersion of the VFS is less than 3.
1194*/
1195typedef struct sqlite3_vfs sqlite3_vfs;
1196typedef void (*sqlite3_syscall_ptr)(void);
1197struct sqlite3_vfs {
1198 int iVersion; /* Structure version number (currently 3) */
1199 int szOsFile; /* Size of subclassed sqlite3_file */
1200 int mxPathname; /* Maximum file pathname length */
1201 sqlite3_vfs *pNext; /* Next registered VFS */
1202 const char *zName; /* Name of this virtual file system */
1203 void *pAppData; /* Pointer to application-specific data */
1204 int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
1205 int flags, int *pOutFlags);
1206 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1207 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1208 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1209 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1210 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1211 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1212 void (*xDlClose)(sqlite3_vfs*, void*);
1213 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1214 int (*xSleep)(sqlite3_vfs*, int microseconds);
1215 int (*xCurrentTime)(sqlite3_vfs*, double*);
1216 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1217 /*
1218 ** The methods above are in version 1 of the sqlite_vfs object
1219 ** definition. Those that follow are added in version 2 or later
1220 */
1221 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1222 /*
1223 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1224 ** Those below are for version 3 and greater.
1225 */
1226 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1227 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1228 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1229 /*
1230 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1231 ** New fields may be appended in future versions. The iVersion
1232 ** value will increment whenever this happens.
1233 */
1234};
1235
1236/*
1237** CAPI3REF: Flags for the xAccess VFS method
1238**
1239** These integer constants can be used as the third parameter to
1240** the xAccess method of an [sqlite3_vfs] object. They determine
1241** what kind of permissions the xAccess method is looking for.
1242** With SQLITE_ACCESS_EXISTS, the xAccess method
1243** simply checks whether the file exists.
1244** With SQLITE_ACCESS_READWRITE, the xAccess method
1245** checks whether the named directory is both readable and writable
1246** (in other words, if files can be added, removed, and renamed within
1247** the directory).
1248** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1249** [temp_store_directory pragma], though this could change in a future
1250** release of SQLite.
1251** With SQLITE_ACCESS_READ, the xAccess method
1252** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1253** currently unused, though it might be used in a future release of
1254** SQLite.
1255*/
1256#define SQLITE_ACCESS_EXISTS 0
1257#define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1258#define SQLITE_ACCESS_READ 2 /* Unused */
1259
1260/*
1261** CAPI3REF: Flags for the xShmLock VFS method
1262**
1263** These integer constants define the various locking operations
1264** allowed by the xShmLock method of [sqlite3_io_methods]. The
1265** following are the only legal combinations of flags to the
1266** xShmLock method:
1267**
1268** <ul>
1269** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1270** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1271** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1272** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1273** </ul>
1274**
1275** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1276** was given on the corresponding lock.
1277**
1278** The xShmLock method can transition between unlocked and SHARED or
1279** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1280** and EXCLUSIVE.
1281*/
1282#define SQLITE_SHM_UNLOCK 1
1283#define SQLITE_SHM_LOCK 2
1284#define SQLITE_SHM_SHARED 4
1285#define SQLITE_SHM_EXCLUSIVE 8
1286
1287/*
1288** CAPI3REF: Maximum xShmLock index
1289**
1290** The xShmLock method on [sqlite3_io_methods] may use values
1291** between 0 and this upper bound as its "offset" argument.
1292** The SQLite core will never attempt to acquire or release a
1293** lock outside of this range
1294*/
1295#define SQLITE_SHM_NLOCK 8
1296
1297
1298/*
1299** CAPI3REF: Initialize The SQLite Library
1300**
1301** ^The sqlite3_initialize() routine initializes the
1302** SQLite library. ^The sqlite3_shutdown() routine
1303** deallocates any resources that were allocated by sqlite3_initialize().
1304** These routines are designed to aid in process initialization and
1305** shutdown on embedded systems. Workstation applications using
1306** SQLite normally do not need to invoke either of these routines.
1307**
1308** A call to sqlite3_initialize() is an "effective" call if it is
1309** the first time sqlite3_initialize() is invoked during the lifetime of
1310** the process, or if it is the first time sqlite3_initialize() is invoked
1311** following a call to sqlite3_shutdown(). ^(Only an effective call
1312** of sqlite3_initialize() does any initialization. All other calls
1313** are harmless no-ops.)^
1314**
1315** A call to sqlite3_shutdown() is an "effective" call if it is the first
1316** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1317** an effective call to sqlite3_shutdown() does any deinitialization.
1318** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1319**
1320** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1321** is not. The sqlite3_shutdown() interface must only be called from a
1322** single thread. All open [database connections] must be closed and all
1323** other SQLite resources must be deallocated prior to invoking
1324** sqlite3_shutdown().
1325**
1326** Among other things, ^sqlite3_initialize() will invoke
1327** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1328** will invoke sqlite3_os_end().
1329**
1330** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1331** ^If for some reason, sqlite3_initialize() is unable to initialize
1332** the library (perhaps it is unable to allocate a needed resource such
1333** as a mutex) it returns an [error code] other than [SQLITE_OK].
1334**
1335** ^The sqlite3_initialize() routine is called internally by many other
1336** SQLite interfaces so that an application usually does not need to
1337** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1338** calls sqlite3_initialize() so the SQLite library will be automatically
1339** initialized when [sqlite3_open()] is called if it has not be initialized
1340** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1341** compile-time option, then the automatic calls to sqlite3_initialize()
1342** are omitted and the application must call sqlite3_initialize() directly
1343** prior to using any other SQLite interface. For maximum portability,
1344** it is recommended that applications always invoke sqlite3_initialize()
1345** directly prior to using any other SQLite interface. Future releases
1346** of SQLite may require this. In other words, the behavior exhibited
1347** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1348** default behavior in some future release of SQLite.
1349**
1350** The sqlite3_os_init() routine does operating-system specific
1351** initialization of the SQLite library. The sqlite3_os_end()
1352** routine undoes the effect of sqlite3_os_init(). Typical tasks
1353** performed by these routines include allocation or deallocation
1354** of static resources, initialization of global variables,
1355** setting up a default [sqlite3_vfs] module, or setting up
1356** a default configuration using [sqlite3_config()].
1357**
1358** The application should never invoke either sqlite3_os_init()
1359** or sqlite3_os_end() directly. The application should only invoke
1360** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1361** interface is called automatically by sqlite3_initialize() and
1362** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1363** implementations for sqlite3_os_init() and sqlite3_os_end()
1364** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1365** When [custom builds | built for other platforms]
1366** (using the [SQLITE_OS_OTHER=1] compile-time
1367** option) the application must supply a suitable implementation for
1368** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1369** implementation of sqlite3_os_init() or sqlite3_os_end()
1370** must return [SQLITE_OK] on success and some other [error code] upon
1371** failure.
1372*/
1373SQLITE_API int SQLITE_STDCALL sqlite3_initialize(void);
1374SQLITE_API int SQLITE_STDCALL sqlite3_shutdown(void);
1375SQLITE_API int SQLITE_STDCALL sqlite3_os_init(void);
1376SQLITE_API int SQLITE_STDCALL sqlite3_os_end(void);
1377
1378/*
1379** CAPI3REF: Configuring The SQLite Library
1380**
1381** The sqlite3_config() interface is used to make global configuration
1382** changes to SQLite in order to tune SQLite to the specific needs of
1383** the application. The default configuration is recommended for most
1384** applications and so this routine is usually not necessary. It is
1385** provided to support rare applications with unusual needs.
1386**
1387** <b>The sqlite3_config() interface is not threadsafe. The application
1388** must ensure that no other SQLite interfaces are invoked by other
1389** threads while sqlite3_config() is running.</b>
1390**
1391** The sqlite3_config() interface
1392** may only be invoked prior to library initialization using
1393** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1394** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1395** [sqlite3_shutdown()] then it will return SQLITE_MISUSE.
1396** Note, however, that ^sqlite3_config() can be called as part of the
1397** implementation of an application-defined [sqlite3_os_init()].
1398**
1399** The first argument to sqlite3_config() is an integer
1400** [configuration option] that determines
1401** what property of SQLite is to be configured. Subsequent arguments
1402** vary depending on the [configuration option]
1403** in the first argument.
1404**
1405** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1406** ^If the option is unknown or SQLite is unable to set the option
1407** then this routine returns a non-zero [error code].
1408*/
1409SQLITE_API int SQLITE_CDECL sqlite3_config(int, ...);
1410
1411/*
1412** CAPI3REF: Configure database connections
1413** METHOD: sqlite3
1414**
1415** The sqlite3_db_config() interface is used to make configuration
1416** changes to a [database connection]. The interface is similar to
1417** [sqlite3_config()] except that the changes apply to a single
1418** [database connection] (specified in the first argument).
1419**
1420** The second argument to sqlite3_db_config(D,V,...) is the
1421** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1422** that indicates what aspect of the [database connection] is being configured.
1423** Subsequent arguments vary depending on the configuration verb.
1424**
1425** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1426** the call is considered successful.
1427*/
1428SQLITE_API int SQLITE_CDECL sqlite3_db_config(sqlite3*, int op, ...);
1429
1430/*
1431** CAPI3REF: Memory Allocation Routines
1432**
1433** An instance of this object defines the interface between SQLite
1434** and low-level memory allocation routines.
1435**
1436** This object is used in only one place in the SQLite interface.
1437** A pointer to an instance of this object is the argument to
1438** [sqlite3_config()] when the configuration option is
1439** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1440** By creating an instance of this object
1441** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1442** during configuration, an application can specify an alternative
1443** memory allocation subsystem for SQLite to use for all of its
1444** dynamic memory needs.
1445**
1446** Note that SQLite comes with several [built-in memory allocators]
1447** that are perfectly adequate for the overwhelming majority of applications
1448** and that this object is only useful to a tiny minority of applications
1449** with specialized memory allocation requirements. This object is
1450** also used during testing of SQLite in order to specify an alternative
1451** memory allocator that simulates memory out-of-memory conditions in
1452** order to verify that SQLite recovers gracefully from such
1453** conditions.
1454**
1455** The xMalloc, xRealloc, and xFree methods must work like the
1456** malloc(), realloc() and free() functions from the standard C library.
1457** ^SQLite guarantees that the second argument to
1458** xRealloc is always a value returned by a prior call to xRoundup.
1459**
1460** xSize should return the allocated size of a memory allocation
1461** previously obtained from xMalloc or xRealloc. The allocated size
1462** is always at least as big as the requested size but may be larger.
1463**
1464** The xRoundup method returns what would be the allocated size of
1465** a memory allocation given a particular requested size. Most memory
1466** allocators round up memory allocations at least to the next multiple
1467** of 8. Some allocators round up to a larger multiple or to a power of 2.
1468** Every memory allocation request coming in through [sqlite3_malloc()]
1469** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1470** that causes the corresponding memory allocation to fail.
1471**
1472** The xInit method initializes the memory allocator. For example,
1473** it might allocate any require mutexes or initialize internal data
1474** structures. The xShutdown method is invoked (indirectly) by
1475** [sqlite3_shutdown()] and should deallocate any resources acquired
1476** by xInit. The pAppData pointer is used as the only parameter to
1477** xInit and xShutdown.
1478**
1479** SQLite holds the [SQLITE_MUTEX_STATIC_MASTER] mutex when it invokes
1480** the xInit method, so the xInit method need not be threadsafe. The
1481** xShutdown method is only called from [sqlite3_shutdown()] so it does
1482** not need to be threadsafe either. For all other methods, SQLite
1483** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1484** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1485** it is by default) and so the methods are automatically serialized.
1486** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1487** methods must be threadsafe or else make their own arrangements for
1488** serialization.
1489**
1490** SQLite will never invoke xInit() more than once without an intervening
1491** call to xShutdown().
1492*/
1493typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1494struct sqlite3_mem_methods {
1495 void *(*xMalloc)(int); /* Memory allocation function */
1496 void (*xFree)(void*); /* Free a prior allocation */
1497 void *(*xRealloc)(void*,int); /* Resize an allocation */
1498 int (*xSize)(void*); /* Return the size of an allocation */
1499 int (*xRoundup)(int); /* Round up request size to allocation size */
1500 int (*xInit)(void*); /* Initialize the memory allocator */
1501 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1502 void *pAppData; /* Argument to xInit() and xShutdown() */
1503};
1504
1505/*
1506** CAPI3REF: Configuration Options
1507** KEYWORDS: {configuration option}
1508**
1509** These constants are the available integer configuration options that
1510** can be passed as the first argument to the [sqlite3_config()] interface.
1511**
1512** New configuration options may be added in future releases of SQLite.
1513** Existing configuration options might be discontinued. Applications
1514** should check the return code from [sqlite3_config()] to make sure that
1515** the call worked. The [sqlite3_config()] interface will return a
1516** non-zero [error code] if a discontinued or unsupported configuration option
1517** is invoked.
1518**
1519** <dl>
1520** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1521** <dd>There are no arguments to this option. ^This option sets the
1522** [threading mode] to Single-thread. In other words, it disables
1523** all mutexing and puts SQLite into a mode where it can only be used
1524** by a single thread. ^If SQLite is compiled with
1525** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1526** it is not possible to change the [threading mode] from its default
1527** value of Single-thread and so [sqlite3_config()] will return
1528** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1529** configuration option.</dd>
1530**
1531** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1532** <dd>There are no arguments to this option. ^This option sets the
1533** [threading mode] to Multi-thread. In other words, it disables
1534** mutexing on [database connection] and [prepared statement] objects.
1535** The application is responsible for serializing access to
1536** [database connections] and [prepared statements]. But other mutexes
1537** are enabled so that SQLite will be safe to use in a multi-threaded
1538** environment as long as no two threads attempt to use the same
1539** [database connection] at the same time. ^If SQLite is compiled with
1540** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1541** it is not possible to set the Multi-thread [threading mode] and
1542** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1543** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1544**
1545** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1546** <dd>There are no arguments to this option. ^This option sets the
1547** [threading mode] to Serialized. In other words, this option enables
1548** all mutexes including the recursive
1549** mutexes on [database connection] and [prepared statement] objects.
1550** In this mode (which is the default when SQLite is compiled with
1551** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1552** to [database connections] and [prepared statements] so that the
1553** application is free to use the same [database connection] or the
1554** same [prepared statement] in different threads at the same time.
1555** ^If SQLite is compiled with
1556** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1557** it is not possible to set the Serialized [threading mode] and
1558** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1559** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1560**
1561** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1562** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1563** a pointer to an instance of the [sqlite3_mem_methods] structure.
1564** The argument specifies
1565** alternative low-level memory allocation routines to be used in place of
1566** the memory allocation routines built into SQLite.)^ ^SQLite makes
1567** its own private copy of the content of the [sqlite3_mem_methods] structure
1568** before the [sqlite3_config()] call returns.</dd>
1569**
1570** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1571** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1572** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1573** The [sqlite3_mem_methods]
1574** structure is filled with the currently defined memory allocation routines.)^
1575** This option can be used to overload the default memory allocation
1576** routines with a wrapper that simulations memory allocation failure or
1577** tracks memory usage, for example. </dd>
1578**
1579** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1580** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1581** interpreted as a boolean, which enables or disables the collection of
1582** memory allocation statistics. ^(When memory allocation statistics are
1583** disabled, the following SQLite interfaces become non-operational:
1584** <ul>
1585** <li> [sqlite3_memory_used()]
1586** <li> [sqlite3_memory_highwater()]
1587** <li> [sqlite3_soft_heap_limit64()]
1588** <li> [sqlite3_status64()]
1589** </ul>)^
1590** ^Memory allocation statistics are enabled by default unless SQLite is
1591** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1592** allocation statistics are disabled by default.
1593** </dd>
1594**
1595** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1596** <dd> ^The SQLITE_CONFIG_SCRATCH option specifies a static memory buffer
1597** that SQLite can use for scratch memory. ^(There are three arguments
1598** to SQLITE_CONFIG_SCRATCH: A pointer an 8-byte
1599** aligned memory buffer from which the scratch allocations will be
1600** drawn, the size of each scratch allocation (sz),
1601** and the maximum number of scratch allocations (N).)^
1602** The first argument must be a pointer to an 8-byte aligned buffer
1603** of at least sz*N bytes of memory.
1604** ^SQLite will not use more than one scratch buffers per thread.
1605** ^SQLite will never request a scratch buffer that is more than 6
1606** times the database page size.
1607** ^If SQLite needs needs additional
1608** scratch memory beyond what is provided by this configuration option, then
1609** [sqlite3_malloc()] will be used to obtain the memory needed.<p>
1610** ^When the application provides any amount of scratch memory using
1611** SQLITE_CONFIG_SCRATCH, SQLite avoids unnecessary large
1612** [sqlite3_malloc|heap allocations].
1613** This can help [Robson proof|prevent memory allocation failures] due to heap
1614** fragmentation in low-memory embedded systems.
1615** </dd>
1616**
1617** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1618** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1619** that SQLite can use for the database page cache with the default page
1620** cache implementation.
1621** This configuration option is a no-op if an application-define page
1622** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1623** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1624** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1625** and the number of cache lines (N).
1626** The sz argument should be the size of the largest database page
1627** (a power of two between 512 and 65536) plus some extra bytes for each
1628** page header. ^The number of extra bytes needed by the page header
1629** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1630** ^It is harmless, apart from the wasted memory,
1631** for the sz parameter to be larger than necessary. The pMem
1632** argument must be either a NULL pointer or a pointer to an 8-byte
1633** aligned block of memory of at least sz*N bytes, otherwise
1634** subsequent behavior is undefined.
1635** ^When pMem is not NULL, SQLite will strive to use the memory provided
1636** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1637** a page cache line is larger than sz bytes or if all of the pMem buffer
1638** is exhausted.
1639** ^If pMem is NULL and N is non-zero, then each database connection
1640** does an initial bulk allocation for page cache memory
1641** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1642** of -1024*N bytes if N is negative, . ^If additional
1643** page cache memory is needed beyond what is provided by the initial
1644** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1645** additional cache line. </dd>
1646**
1647** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1648** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1649** that SQLite will use for all of its dynamic memory allocation needs
1650** beyond those provided for by [SQLITE_CONFIG_SCRATCH] and
1651** [SQLITE_CONFIG_PAGECACHE].
1652** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1653** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1654** [SQLITE_ERROR] if invoked otherwise.
1655** ^There are three arguments to SQLITE_CONFIG_HEAP:
1656** An 8-byte aligned pointer to the memory,
1657** the number of bytes in the memory buffer, and the minimum allocation size.
1658** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1659** to using its default memory allocator (the system malloc() implementation),
1660** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1661** memory pointer is not NULL then the alternative memory
1662** allocator is engaged to handle all of SQLites memory allocation needs.
1663** The first pointer (the memory pointer) must be aligned to an 8-byte
1664** boundary or subsequent behavior of SQLite will be undefined.
1665** The minimum allocation size is capped at 2**12. Reasonable values
1666** for the minimum allocation size are 2**5 through 2**8.</dd>
1667**
1668** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1669** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1670** pointer to an instance of the [sqlite3_mutex_methods] structure.
1671** The argument specifies alternative low-level mutex routines to be used
1672** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1673** the content of the [sqlite3_mutex_methods] structure before the call to
1674** [sqlite3_config()] returns. ^If SQLite is compiled with
1675** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1676** the entire mutexing subsystem is omitted from the build and hence calls to
1677** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1678** return [SQLITE_ERROR].</dd>
1679**
1680** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1681** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1682** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1683** [sqlite3_mutex_methods]
1684** structure is filled with the currently defined mutex routines.)^
1685** This option can be used to overload the default mutex allocation
1686** routines with a wrapper used to track mutex usage for performance
1687** profiling or testing, for example. ^If SQLite is compiled with
1688** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1689** the entire mutexing subsystem is omitted from the build and hence calls to
1690** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1691** return [SQLITE_ERROR].</dd>
1692**
1693** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1694** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1695** the default size of lookaside memory on each [database connection].
1696** The first argument is the
1697** size of each lookaside buffer slot and the second is the number of
1698** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1699** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1700** option to [sqlite3_db_config()] can be used to change the lookaside
1701** configuration on individual connections.)^ </dd>
1702**
1703** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1704** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1705** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1706** the interface to a custom page cache implementation.)^
1707** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1708**
1709** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1710** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1711** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1712** the current page cache implementation into that object.)^ </dd>
1713**
1714** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1715** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1716** global [error log].
1717** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
1718** function with a call signature of void(*)(void*,int,const char*),
1719** and a pointer to void. ^If the function pointer is not NULL, it is
1720** invoked by [sqlite3_log()] to process each logging event. ^If the
1721** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
1722** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
1723** passed through as the first parameter to the application-defined logger
1724** function whenever that function is invoked. ^The second parameter to
1725** the logger function is a copy of the first parameter to the corresponding
1726** [sqlite3_log()] call and is intended to be a [result code] or an
1727** [extended result code]. ^The third parameter passed to the logger is
1728** log message after formatting via [sqlite3_snprintf()].
1729** The SQLite logging interface is not reentrant; the logger function
1730** supplied by the application must not invoke any SQLite interface.
1731** In a multi-threaded application, the application-defined logger
1732** function must be threadsafe. </dd>
1733**
1734** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
1735** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
1736** If non-zero, then URI handling is globally enabled. If the parameter is zero,
1737** then URI handling is globally disabled.)^ ^If URI handling is globally
1738** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
1739** [sqlite3_open16()] or
1740** specified as part of [ATTACH] commands are interpreted as URIs, regardless
1741** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
1742** connection is opened. ^If it is globally disabled, filenames are
1743** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
1744** database connection is opened. ^(By default, URI handling is globally
1745** disabled. The default value may be changed by compiling with the
1746** [SQLITE_USE_URI] symbol defined.)^
1747**
1748** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
1749** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
1750** argument which is interpreted as a boolean in order to enable or disable
1751** the use of covering indices for full table scans in the query optimizer.
1752** ^The default setting is determined
1753** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
1754** if that compile-time option is omitted.
1755** The ability to disable the use of covering indices for full table scans
1756** is because some incorrectly coded legacy applications might malfunction
1757** when the optimization is enabled. Providing the ability to
1758** disable the optimization allows the older, buggy application code to work
1759** without change even with newer versions of SQLite.
1760**
1761** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
1762** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
1763** <dd> These options are obsolete and should not be used by new code.
1764** They are retained for backwards compatibility but are now no-ops.
1765** </dd>
1766**
1767** [[SQLITE_CONFIG_SQLLOG]]
1768** <dt>SQLITE_CONFIG_SQLLOG
1769** <dd>This option is only available if sqlite is compiled with the
1770** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
1771** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
1772** The second should be of type (void*). The callback is invoked by the library
1773** in three separate circumstances, identified by the value passed as the
1774** fourth parameter. If the fourth parameter is 0, then the database connection
1775** passed as the second argument has just been opened. The third argument
1776** points to a buffer containing the name of the main database file. If the
1777** fourth parameter is 1, then the SQL statement that the third parameter
1778** points to has just been executed. Or, if the fourth parameter is 2, then
1779** the connection being passed as the second parameter is being closed. The
1780** third parameter is passed NULL In this case. An example of using this
1781** configuration option can be seen in the "test_sqllog.c" source file in
1782** the canonical SQLite source tree.</dd>
1783**
1784** [[SQLITE_CONFIG_MMAP_SIZE]]
1785** <dt>SQLITE_CONFIG_MMAP_SIZE
1786** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
1787** that are the default mmap size limit (the default setting for
1788** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
1789** ^The default setting can be overridden by each database connection using
1790** either the [PRAGMA mmap_size] command, or by using the
1791** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
1792** will be silently truncated if necessary so that it does not exceed the
1793** compile-time maximum mmap size set by the
1794** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
1795** ^If either argument to this option is negative, then that argument is
1796** changed to its compile-time default.
1797**
1798** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
1799** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
1800** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
1801** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
1802** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
1803** that specifies the maximum size of the created heap.
1804**
1805** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
1806** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
1807** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
1808** is a pointer to an integer and writes into that integer the number of extra
1809** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
1810** The amount of extra space required can change depending on the compiler,
1811** target platform, and SQLite version.
1812**
1813** [[SQLITE_CONFIG_PMASZ]]
1814** <dt>SQLITE_CONFIG_PMASZ
1815** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
1816** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
1817** sorter to that integer. The default minimum PMA Size is set by the
1818** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
1819** to help with sort operations when multithreaded sorting
1820** is enabled (using the [PRAGMA threads] command) and the amount of content
1821** to be sorted exceeds the page size times the minimum of the
1822** [PRAGMA cache_size] setting and this value.
1823**
1824** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
1825** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
1826** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
1827** becomes the [statement journal] spill-to-disk threshold.
1828** [Statement journals] are held in memory until their size (in bytes)
1829** exceeds this threshold, at which point they are written to disk.
1830** Or if the threshold is -1, statement journals are always held
1831** exclusively in memory.
1832** Since many statement journals never become large, setting the spill
1833** threshold to a value such as 64KiB can greatly reduce the amount of
1834** I/O required to support statement rollback.
1835** The default value for this setting is controlled by the
1836** [SQLITE_STMTJRNL_SPILL] compile-time option.
1837** </dl>
1838*/
1839#define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
1840#define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
1841#define SQLITE_CONFIG_SERIALIZED 3 /* nil */
1842#define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
1843#define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
1844#define SQLITE_CONFIG_SCRATCH 6 /* void*, int sz, int N */
1845#define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
1846#define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
1847#define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
1848#define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
1849#define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
1850/* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
1851#define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
1852#define SQLITE_CONFIG_PCACHE 14 /* no-op */
1853#define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
1854#define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
1855#define SQLITE_CONFIG_URI 17 /* int */
1856#define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
1857#define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
1858#define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
1859#define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
1860#define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
1861#define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
1862#define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
1863#define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
1864#define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
1865
1866/*
1867** CAPI3REF: Database Connection Configuration Options
1868**
1869** These constants are the available integer configuration options that
1870** can be passed as the second argument to the [sqlite3_db_config()] interface.
1871**
1872** New configuration options may be added in future releases of SQLite.
1873** Existing configuration options might be discontinued. Applications
1874** should check the return code from [sqlite3_db_config()] to make sure that
1875** the call worked. ^The [sqlite3_db_config()] interface will return a
1876** non-zero [error code] if a discontinued or unsupported configuration option
1877** is invoked.
1878**
1879** <dl>
1880** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
1881** <dd> ^This option takes three additional arguments that determine the
1882** [lookaside memory allocator] configuration for the [database connection].
1883** ^The first argument (the third parameter to [sqlite3_db_config()] is a
1884** pointer to a memory buffer to use for lookaside memory.
1885** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
1886** may be NULL in which case SQLite will allocate the
1887** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
1888** size of each lookaside buffer slot. ^The third argument is the number of
1889** slots. The size of the buffer in the first argument must be greater than
1890** or equal to the product of the second and third arguments. The buffer
1891** must be aligned to an 8-byte boundary. ^If the second argument to
1892** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
1893** rounded down to the next smaller multiple of 8. ^(The lookaside memory
1894** configuration for a database connection can only be changed when that
1895** connection is not currently using lookaside memory, or in other words
1896** when the "current value" returned by
1897** [sqlite3_db_status](D,[SQLITE_CONFIG_LOOKASIDE],...) is zero.
1898** Any attempt to change the lookaside memory configuration when lookaside
1899** memory is in use leaves the configuration unchanged and returns
1900** [SQLITE_BUSY].)^</dd>
1901**
1902** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
1903** <dd> ^This option is used to enable or disable the enforcement of
1904** [foreign key constraints]. There should be two additional arguments.
1905** The first argument is an integer which is 0 to disable FK enforcement,
1906** positive to enable FK enforcement or negative to leave FK enforcement
1907** unchanged. The second parameter is a pointer to an integer into which
1908** is written 0 or 1 to indicate whether FK enforcement is off or on
1909** following this call. The second parameter may be a NULL pointer, in
1910** which case the FK enforcement setting is not reported back. </dd>
1911**
1912** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
1913** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
1914** There should be two additional arguments.
1915** The first argument is an integer which is 0 to disable triggers,
1916** positive to enable triggers or negative to leave the setting unchanged.
1917** The second parameter is a pointer to an integer into which
1918** is written 0 or 1 to indicate whether triggers are disabled or enabled
1919** following this call. The second parameter may be a NULL pointer, in
1920** which case the trigger setting is not reported back. </dd>
1921**
1922** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
1923** <dd> ^This option is used to enable or disable the two-argument
1924** version of the [fts3_tokenizer()] function which is part of the
1925** [FTS3] full-text search engine extension.
1926** There should be two additional arguments.
1927** The first argument is an integer which is 0 to disable fts3_tokenizer() or
1928** positive to enable fts3_tokenizer() or negative to leave the setting
1929** unchanged.
1930** The second parameter is a pointer to an integer into which
1931** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
1932** following this call. The second parameter may be a NULL pointer, in
1933** which case the new setting is not reported back. </dd>
1934**
1935** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
1936** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
1937** interface independently of the [load_extension()] SQL function.
1938** The [sqlite3_enable_load_extension()] API enables or disables both the
1939** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
1940** There should be two additional arguments.
1941** When the first argument to this interface is 1, then only the C-API is
1942** enabled and the SQL function remains disabled. If the first argment to
1943** this interface is 0, then both the C-API and the SQL function are disabled.
1944** If the first argument is -1, then no changes are made to state of either the
1945** C-API or the SQL function.
1946** The second parameter is a pointer to an integer into which
1947** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
1948** is disabled or enabled following this call. The second parameter may
1949** be a NULL pointer, in which case the new setting is not reported back.
1950** </dd>
1951**
1952** </dl>
1953*/
1954#define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
1955#define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
1956#define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
1957#define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
1958#define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
1959
1960
1961/*
1962** CAPI3REF: Enable Or Disable Extended Result Codes
1963** METHOD: sqlite3
1964**
1965** ^The sqlite3_extended_result_codes() routine enables or disables the
1966** [extended result codes] feature of SQLite. ^The extended result
1967** codes are disabled by default for historical compatibility.
1968*/
1969SQLITE_API int SQLITE_STDCALL sqlite3_extended_result_codes(sqlite3*, int onoff);
1970
1971/*
1972** CAPI3REF: Last Insert Rowid
1973** METHOD: sqlite3
1974**
1975** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
1976** has a unique 64-bit signed
1977** integer key called the [ROWID | "rowid"]. ^The rowid is always available
1978** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
1979** names are not also used by explicitly declared columns. ^If
1980** the table has a column of type [INTEGER PRIMARY KEY] then that column
1981** is another alias for the rowid.
1982**
1983** ^The sqlite3_last_insert_rowid(D) interface returns the [rowid] of the
1984** most recent successful [INSERT] into a rowid table or [virtual table]
1985** on database connection D.
1986** ^Inserts into [WITHOUT ROWID] tables are not recorded.
1987** ^If no successful [INSERT]s into rowid tables
1988** have ever occurred on the database connection D,
1989** then sqlite3_last_insert_rowid(D) returns zero.
1990**
1991** ^(If an [INSERT] occurs within a trigger or within a [virtual table]
1992** method, then this routine will return the [rowid] of the inserted
1993** row as long as the trigger or virtual table method is running.
1994** But once the trigger or virtual table method ends, the value returned
1995** by this routine reverts to what it was before the trigger or virtual
1996** table method began.)^
1997**
1998** ^An [INSERT] that fails due to a constraint violation is not a
1999** successful [INSERT] and does not change the value returned by this
2000** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2001** and INSERT OR ABORT make no changes to the return value of this
2002** routine when their insertion fails. ^(When INSERT OR REPLACE
2003** encounters a constraint violation, it does not fail. The
2004** INSERT continues to completion after deleting rows that caused
2005** the constraint problem so INSERT OR REPLACE will always change
2006** the return value of this interface.)^
2007**
2008** ^For the purposes of this routine, an [INSERT] is considered to
2009** be successful even if it is subsequently rolled back.
2010**
2011** This function is accessible to SQL statements via the
2012** [last_insert_rowid() SQL function].
2013**
2014** If a separate thread performs a new [INSERT] on the same
2015** database connection while the [sqlite3_last_insert_rowid()]
2016** function is running and thus changes the last insert [rowid],
2017** then the value returned by [sqlite3_last_insert_rowid()] is
2018** unpredictable and might not equal either the old or the new
2019** last insert [rowid].
2020*/
2021SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_last_insert_rowid(sqlite3*);
2022
2023/*
2024** CAPI3REF: Count The Number Of Rows Modified
2025** METHOD: sqlite3
2026**
2027** ^This function returns the number of rows modified, inserted or
2028** deleted by the most recently completed INSERT, UPDATE or DELETE
2029** statement on the database connection specified by the only parameter.
2030** ^Executing any other type of SQL statement does not modify the value
2031** returned by this function.
2032**
2033** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2034** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2035** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2036**
2037** Changes to a view that are intercepted by
2038** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2039** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2040** DELETE statement run on a view is always zero. Only changes made to real
2041** tables are counted.
2042**
2043** Things are more complicated if the sqlite3_changes() function is
2044** executed while a trigger program is running. This may happen if the
2045** program uses the [changes() SQL function], or if some other callback
2046** function invokes sqlite3_changes() directly. Essentially:
2047**
2048** <ul>
2049** <li> ^(Before entering a trigger program the value returned by
2050** sqlite3_changes() function is saved. After the trigger program
2051** has finished, the original value is restored.)^
2052**
2053** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2054** statement sets the value returned by sqlite3_changes()
2055** upon completion as normal. Of course, this value will not include
2056** any changes performed by sub-triggers, as the sqlite3_changes()
2057** value will be saved and restored after each sub-trigger has run.)^
2058** </ul>
2059**
2060** ^This means that if the changes() SQL function (or similar) is used
2061** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2062** returns the value as set when the calling statement began executing.
2063** ^If it is used by the second or subsequent such statement within a trigger
2064** program, the value returned reflects the number of rows modified by the
2065** previous INSERT, UPDATE or DELETE statement within the same trigger.
2066**
2067** See also the [sqlite3_total_changes()] interface, the
2068** [count_changes pragma], and the [changes() SQL function].
2069**
2070** If a separate thread makes changes on the same database connection
2071** while [sqlite3_changes()] is running then the value returned
2072** is unpredictable and not meaningful.
2073*/
2074SQLITE_API int SQLITE_STDCALL sqlite3_changes(sqlite3*);
2075
2076/*
2077** CAPI3REF: Total Number Of Rows Modified
2078** METHOD: sqlite3
2079**
2080** ^This function returns the total number of rows inserted, modified or
2081** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2082** since the database connection was opened, including those executed as
2083** part of trigger programs. ^Executing any other type of SQL statement
2084** does not affect the value returned by sqlite3_total_changes().
2085**
2086** ^Changes made as part of [foreign key actions] are included in the
2087** count, but those made as part of REPLACE constraint resolution are
2088** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2089** are not counted.
2090**
2091** See also the [sqlite3_changes()] interface, the
2092** [count_changes pragma], and the [total_changes() SQL function].
2093**
2094** If a separate thread makes changes on the same database connection
2095** while [sqlite3_total_changes()] is running then the value
2096** returned is unpredictable and not meaningful.
2097*/
2098SQLITE_API int SQLITE_STDCALL sqlite3_total_changes(sqlite3*);
2099
2100/*
2101** CAPI3REF: Interrupt A Long-Running Query
2102** METHOD: sqlite3
2103**
2104** ^This function causes any pending database operation to abort and
2105** return at its earliest opportunity. This routine is typically
2106** called in response to a user action such as pressing "Cancel"
2107** or Ctrl-C where the user wants a long query operation to halt
2108** immediately.
2109**
2110** ^It is safe to call this routine from a thread different from the
2111** thread that is currently running the database operation. But it
2112** is not safe to call this routine with a [database connection] that
2113** is closed or might close before sqlite3_interrupt() returns.
2114**
2115** ^If an SQL operation is very nearly finished at the time when
2116** sqlite3_interrupt() is called, then it might not have an opportunity
2117** to be interrupted and might continue to completion.
2118**
2119** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2120** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2121** that is inside an explicit transaction, then the entire transaction
2122** will be rolled back automatically.
2123**
2124** ^The sqlite3_interrupt(D) call is in effect until all currently running
2125** SQL statements on [database connection] D complete. ^Any new SQL statements
2126** that are started after the sqlite3_interrupt() call and before the
2127** running statements reaches zero are interrupted as if they had been
2128** running prior to the sqlite3_interrupt() call. ^New SQL statements
2129** that are started after the running statement count reaches zero are
2130** not effected by the sqlite3_interrupt().
2131** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2132** SQL statements is a no-op and has no effect on SQL statements
2133** that are started after the sqlite3_interrupt() call returns.
2134**
2135** If the database connection closes while [sqlite3_interrupt()]
2136** is running then bad things will likely happen.
2137*/
2138SQLITE_API void SQLITE_STDCALL sqlite3_interrupt(sqlite3*);
2139
2140/*
2141** CAPI3REF: Determine If An SQL Statement Is Complete
2142**
2143** These routines are useful during command-line input to determine if the
2144** currently entered text seems to form a complete SQL statement or
2145** if additional input is needed before sending the text into
2146** SQLite for parsing. ^These routines return 1 if the input string
2147** appears to be a complete SQL statement. ^A statement is judged to be
2148** complete if it ends with a semicolon token and is not a prefix of a
2149** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2150** string literals or quoted identifier names or comments are not
2151** independent tokens (they are part of the token in which they are
2152** embedded) and thus do not count as a statement terminator. ^Whitespace
2153** and comments that follow the final semicolon are ignored.
2154**
2155** ^These routines return 0 if the statement is incomplete. ^If a
2156** memory allocation fails, then SQLITE_NOMEM is returned.
2157**
2158** ^These routines do not parse the SQL statements thus
2159** will not detect syntactically incorrect SQL.
2160**
2161** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2162** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2163** automatically by sqlite3_complete16(). If that initialization fails,
2164** then the return value from sqlite3_complete16() will be non-zero
2165** regardless of whether or not the input SQL is complete.)^
2166**
2167** The input to [sqlite3_complete()] must be a zero-terminated
2168** UTF-8 string.
2169**
2170** The input to [sqlite3_complete16()] must be a zero-terminated
2171** UTF-16 string in native byte order.
2172*/
2173SQLITE_API int SQLITE_STDCALL sqlite3_complete(const char *sql);
2174SQLITE_API int SQLITE_STDCALL sqlite3_complete16(const void *sql);
2175
2176/*
2177** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2178** KEYWORDS: {busy-handler callback} {busy handler}
2179** METHOD: sqlite3
2180**
2181** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2182** that might be invoked with argument P whenever
2183** an attempt is made to access a database table associated with
2184** [database connection] D when another thread
2185** or process has the table locked.
2186** The sqlite3_busy_handler() interface is used to implement
2187** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2188**
2189** ^If the busy callback is NULL, then [SQLITE_BUSY]
2190** is returned immediately upon encountering the lock. ^If the busy callback
2191** is not NULL, then the callback might be invoked with two arguments.
2192**
2193** ^The first argument to the busy handler is a copy of the void* pointer which
2194** is the third argument to sqlite3_busy_handler(). ^The second argument to
2195** the busy handler callback is the number of times that the busy handler has
2196** been invoked previously for the same locking event. ^If the
2197** busy callback returns 0, then no additional attempts are made to
2198** access the database and [SQLITE_BUSY] is returned
2199** to the application.
2200** ^If the callback returns non-zero, then another attempt
2201** is made to access the database and the cycle repeats.
2202**
2203** The presence of a busy handler does not guarantee that it will be invoked
2204** when there is lock contention. ^If SQLite determines that invoking the busy
2205** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2206** to the application instead of invoking the
2207** busy handler.
2208** Consider a scenario where one process is holding a read lock that
2209** it is trying to promote to a reserved lock and
2210** a second process is holding a reserved lock that it is trying
2211** to promote to an exclusive lock. The first process cannot proceed
2212** because it is blocked by the second and the second process cannot
2213** proceed because it is blocked by the first. If both processes
2214** invoke the busy handlers, neither will make any progress. Therefore,
2215** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2216** will induce the first process to release its read lock and allow
2217** the second process to proceed.
2218**
2219** ^The default busy callback is NULL.
2220**
2221** ^(There can only be a single busy handler defined for each
2222** [database connection]. Setting a new busy handler clears any
2223** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2224** or evaluating [PRAGMA busy_timeout=N] will change the
2225** busy handler and thus clear any previously set busy handler.
2226**
2227** The busy callback should not take any actions which modify the
2228** database connection that invoked the busy handler. In other words,
2229** the busy handler is not reentrant. Any such actions
2230** result in undefined behavior.
2231**
2232** A busy handler must not close the database connection
2233** or [prepared statement] that invoked the busy handler.
2234*/
2235SQLITE_API int SQLITE_STDCALL sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
2236
2237/*
2238** CAPI3REF: Set A Busy Timeout
2239** METHOD: sqlite3
2240**
2241** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2242** for a specified amount of time when a table is locked. ^The handler
2243** will sleep multiple times until at least "ms" milliseconds of sleeping
2244** have accumulated. ^After at least "ms" milliseconds of sleeping,
2245** the handler returns 0 which causes [sqlite3_step()] to return
2246** [SQLITE_BUSY].
2247**
2248** ^Calling this routine with an argument less than or equal to zero
2249** turns off all busy handlers.
2250**
2251** ^(There can only be a single busy handler for a particular
2252** [database connection] at any given moment. If another busy handler
2253** was defined (using [sqlite3_busy_handler()]) prior to calling
2254** this routine, that other busy handler is cleared.)^
2255**
2256** See also: [PRAGMA busy_timeout]
2257*/
2258SQLITE_API int SQLITE_STDCALL sqlite3_busy_timeout(sqlite3*, int ms);
2259
2260/*
2261** CAPI3REF: Convenience Routines For Running Queries
2262** METHOD: sqlite3
2263**
2264** This is a legacy interface that is preserved for backwards compatibility.
2265** Use of this interface is not recommended.
2266**
2267** Definition: A <b>result table</b> is memory data structure created by the
2268** [sqlite3_get_table()] interface. A result table records the
2269** complete query results from one or more queries.
2270**
2271** The table conceptually has a number of rows and columns. But
2272** these numbers are not part of the result table itself. These
2273** numbers are obtained separately. Let N be the number of rows
2274** and M be the number of columns.
2275**
2276** A result table is an array of pointers to zero-terminated UTF-8 strings.
2277** There are (N+1)*M elements in the array. The first M pointers point
2278** to zero-terminated strings that contain the names of the columns.
2279** The remaining entries all point to query results. NULL values result
2280** in NULL pointers. All other values are in their UTF-8 zero-terminated
2281** string representation as returned by [sqlite3_column_text()].
2282**
2283** A result table might consist of one or more memory allocations.
2284** It is not safe to pass a result table directly to [sqlite3_free()].
2285** A result table should be deallocated using [sqlite3_free_table()].
2286**
2287** ^(As an example of the result table format, suppose a query result
2288** is as follows:
2289**
2290** <blockquote><pre>
2291** Name | Age
2292** -----------------------
2293** Alice | 43
2294** Bob | 28
2295** Cindy | 21
2296** </pre></blockquote>
2297**
2298** There are two column (M==2) and three rows (N==3). Thus the
2299** result table has 8 entries. Suppose the result table is stored
2300** in an array names azResult. Then azResult holds this content:
2301**
2302** <blockquote><pre>
2303** azResult[0] = "Name";
2304** azResult[1] = "Age";
2305** azResult[2] = "Alice";
2306** azResult[3] = "43";
2307** azResult[4] = "Bob";
2308** azResult[5] = "28";
2309** azResult[6] = "Cindy";
2310** azResult[7] = "21";
2311** </pre></blockquote>)^
2312**
2313** ^The sqlite3_get_table() function evaluates one or more
2314** semicolon-separated SQL statements in the zero-terminated UTF-8
2315** string of its 2nd parameter and returns a result table to the
2316** pointer given in its 3rd parameter.
2317**
2318** After the application has finished with the result from sqlite3_get_table(),
2319** it must pass the result table pointer to sqlite3_free_table() in order to
2320** release the memory that was malloced. Because of the way the
2321** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2322** function must not try to call [sqlite3_free()] directly. Only
2323** [sqlite3_free_table()] is able to release the memory properly and safely.
2324**
2325** The sqlite3_get_table() interface is implemented as a wrapper around
2326** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2327** to any internal data structures of SQLite. It uses only the public
2328** interface defined here. As a consequence, errors that occur in the
2329** wrapper layer outside of the internal [sqlite3_exec()] call are not
2330** reflected in subsequent calls to [sqlite3_errcode()] or
2331** [sqlite3_errmsg()].
2332*/
2333SQLITE_API int SQLITE_STDCALL sqlite3_get_table(
2334 sqlite3 *db, /* An open database */
2335 const char *zSql, /* SQL to be evaluated */
2336 char ***pazResult, /* Results of the query */
2337 int *pnRow, /* Number of result rows written here */
2338 int *pnColumn, /* Number of result columns written here */
2339 char **pzErrmsg /* Error msg written here */
2340);
2341SQLITE_API void SQLITE_STDCALL sqlite3_free_table(char **result);
2342
2343/*
2344** CAPI3REF: Formatted String Printing Functions
2345**
2346** These routines are work-alikes of the "printf()" family of functions
2347** from the standard C library.
2348** These routines understand most of the common K&R formatting options,
2349** plus some additional non-standard formats, detailed below.
2350** Note that some of the more obscure formatting options from recent
2351** C-library standards are omitted from this implementation.
2352**
2353** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2354** results into memory obtained from [sqlite3_malloc()].
2355** The strings returned by these two routines should be
2356** released by [sqlite3_free()]. ^Both routines return a
2357** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
2358** memory to hold the resulting string.
2359**
2360** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2361** the standard C library. The result is written into the
2362** buffer supplied as the second parameter whose size is given by
2363** the first parameter. Note that the order of the
2364** first two parameters is reversed from snprintf().)^ This is an
2365** historical accident that cannot be fixed without breaking
2366** backwards compatibility. ^(Note also that sqlite3_snprintf()
2367** returns a pointer to its buffer instead of the number of
2368** characters actually written into the buffer.)^ We admit that
2369** the number of characters written would be a more useful return
2370** value but we cannot change the implementation of sqlite3_snprintf()
2371** now without breaking compatibility.
2372**
2373** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2374** guarantees that the buffer is always zero-terminated. ^The first
2375** parameter "n" is the total size of the buffer, including space for
2376** the zero terminator. So the longest string that can be completely
2377** written will be n-1 characters.
2378**
2379** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
2380**
2381** These routines all implement some additional formatting
2382** options that are useful for constructing SQL statements.
2383** All of the usual printf() formatting options apply. In addition, there
2384** is are "%q", "%Q", "%w" and "%z" options.
2385**
2386** ^(The %q option works like %s in that it substitutes a nul-terminated
2387** string from the argument list. But %q also doubles every '\'' character.
2388** %q is designed for use inside a string literal.)^ By doubling each '\''
2389** character it escapes that character and allows it to be inserted into
2390** the string.
2391**
2392** For example, assume the string variable zText contains text as follows:
2393**
2394** <blockquote><pre>
2395** char *zText = "It's a happy day!";
2396** </pre></blockquote>
2397**
2398** One can use this text in an SQL statement as follows:
2399**
2400** <blockquote><pre>
2401** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
2402** sqlite3_exec(db, zSQL, 0, 0, 0);
2403** sqlite3_free(zSQL);
2404** </pre></blockquote>
2405**
2406** Because the %q format string is used, the '\'' character in zText
2407** is escaped and the SQL generated is as follows:
2408**
2409** <blockquote><pre>
2410** INSERT INTO table1 VALUES('It''s a happy day!')
2411** </pre></blockquote>
2412**
2413** This is correct. Had we used %s instead of %q, the generated SQL
2414** would have looked like this:
2415**
2416** <blockquote><pre>
2417** INSERT INTO table1 VALUES('It's a happy day!');
2418** </pre></blockquote>
2419**
2420** This second example is an SQL syntax error. As a general rule you should
2421** always use %q instead of %s when inserting text into a string literal.
2422**
2423** ^(The %Q option works like %q except it also adds single quotes around
2424** the outside of the total string. Additionally, if the parameter in the
2425** argument list is a NULL pointer, %Q substitutes the text "NULL" (without
2426** single quotes).)^ So, for example, one could say:
2427**
2428** <blockquote><pre>
2429** char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
2430** sqlite3_exec(db, zSQL, 0, 0, 0);
2431** sqlite3_free(zSQL);
2432** </pre></blockquote>
2433**
2434** The code above will render a correct SQL statement in the zSQL
2435** variable even if the zText variable is a NULL pointer.
2436**
2437** ^(The "%w" formatting option is like "%q" except that it expects to
2438** be contained within double-quotes instead of single quotes, and it
2439** escapes the double-quote character instead of the single-quote
2440** character.)^ The "%w" formatting option is intended for safely inserting
2441** table and column names into a constructed SQL statement.
2442**
2443** ^(The "%z" formatting option works like "%s" but with the
2444** addition that after the string has been read and copied into
2445** the result, [sqlite3_free()] is called on the input string.)^
2446*/
2447SQLITE_API char *SQLITE_CDECL sqlite3_mprintf(const char*,...);
2448SQLITE_API char *SQLITE_STDCALL sqlite3_vmprintf(const char*, va_list);
2449SQLITE_API char *SQLITE_CDECL sqlite3_snprintf(int,char*,const char*, ...);
2450SQLITE_API char *SQLITE_STDCALL sqlite3_vsnprintf(int,char*,const char*, va_list);
2451
2452/*
2453** CAPI3REF: Memory Allocation Subsystem
2454**
2455** The SQLite core uses these three routines for all of its own
2456** internal memory allocation needs. "Core" in the previous sentence
2457** does not include operating-system specific VFS implementation. The
2458** Windows VFS uses native malloc() and free() for some operations.
2459**
2460** ^The sqlite3_malloc() routine returns a pointer to a block
2461** of memory at least N bytes in length, where N is the parameter.
2462** ^If sqlite3_malloc() is unable to obtain sufficient free
2463** memory, it returns a NULL pointer. ^If the parameter N to
2464** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
2465** a NULL pointer.
2466**
2467** ^The sqlite3_malloc64(N) routine works just like
2468** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
2469** of a signed 32-bit integer.
2470**
2471** ^Calling sqlite3_free() with a pointer previously returned
2472** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
2473** that it might be reused. ^The sqlite3_free() routine is
2474** a no-op if is called with a NULL pointer. Passing a NULL pointer
2475** to sqlite3_free() is harmless. After being freed, memory
2476** should neither be read nor written. Even reading previously freed
2477** memory might result in a segmentation fault or other severe error.
2478** Memory corruption, a segmentation fault, or other severe error
2479** might result if sqlite3_free() is called with a non-NULL pointer that
2480** was not obtained from sqlite3_malloc() or sqlite3_realloc().
2481**
2482** ^The sqlite3_realloc(X,N) interface attempts to resize a
2483** prior memory allocation X to be at least N bytes.
2484** ^If the X parameter to sqlite3_realloc(X,N)
2485** is a NULL pointer then its behavior is identical to calling
2486** sqlite3_malloc(N).
2487** ^If the N parameter to sqlite3_realloc(X,N) is zero or
2488** negative then the behavior is exactly the same as calling
2489** sqlite3_free(X).
2490** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
2491** of at least N bytes in size or NULL if insufficient memory is available.
2492** ^If M is the size of the prior allocation, then min(N,M) bytes
2493** of the prior allocation are copied into the beginning of buffer returned
2494** by sqlite3_realloc(X,N) and the prior allocation is freed.
2495** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
2496** prior allocation is not freed.
2497**
2498** ^The sqlite3_realloc64(X,N) interfaces works the same as
2499** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
2500** of a 32-bit signed integer.
2501**
2502** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
2503** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
2504** sqlite3_msize(X) returns the size of that memory allocation in bytes.
2505** ^The value returned by sqlite3_msize(X) might be larger than the number
2506** of bytes requested when X was allocated. ^If X is a NULL pointer then
2507** sqlite3_msize(X) returns zero. If X points to something that is not
2508** the beginning of memory allocation, or if it points to a formerly
2509** valid memory allocation that has now been freed, then the behavior
2510** of sqlite3_msize(X) is undefined and possibly harmful.
2511**
2512** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
2513** sqlite3_malloc64(), and sqlite3_realloc64()
2514** is always aligned to at least an 8 byte boundary, or to a
2515** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
2516** option is used.
2517**
2518** In SQLite version 3.5.0 and 3.5.1, it was possible to define
2519** the SQLITE_OMIT_MEMORY_ALLOCATION which would cause the built-in
2520** implementation of these routines to be omitted. That capability
2521** is no longer provided. Only built-in memory allocators can be used.
2522**
2523** Prior to SQLite version 3.7.10, the Windows OS interface layer called
2524** the system malloc() and free() directly when converting
2525** filenames between the UTF-8 encoding used by SQLite
2526** and whatever filename encoding is used by the particular Windows
2527** installation. Memory allocation errors were detected, but
2528** they were reported back as [SQLITE_CANTOPEN] or
2529** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
2530**
2531** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
2532** must be either NULL or else pointers obtained from a prior
2533** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
2534** not yet been released.
2535**
2536** The application must not read or write any part of
2537** a block of memory after it has been released using
2538** [sqlite3_free()] or [sqlite3_realloc()].
2539*/
2540SQLITE_API void *SQLITE_STDCALL sqlite3_malloc(int);
2541SQLITE_API void *SQLITE_STDCALL sqlite3_malloc64(sqlite3_uint64);
2542SQLITE_API void *SQLITE_STDCALL sqlite3_realloc(void*, int);
2543SQLITE_API void *SQLITE_STDCALL sqlite3_realloc64(void*, sqlite3_uint64);
2544SQLITE_API void SQLITE_STDCALL sqlite3_free(void*);
2545SQLITE_API sqlite3_uint64 SQLITE_STDCALL sqlite3_msize(void*);
2546
2547/*
2548** CAPI3REF: Memory Allocator Statistics
2549**
2550** SQLite provides these two interfaces for reporting on the status
2551** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
2552** routines, which form the built-in memory allocation subsystem.
2553**
2554** ^The [sqlite3_memory_used()] routine returns the number of bytes
2555** of memory currently outstanding (malloced but not freed).
2556** ^The [sqlite3_memory_highwater()] routine returns the maximum
2557** value of [sqlite3_memory_used()] since the high-water mark
2558** was last reset. ^The values returned by [sqlite3_memory_used()] and
2559** [sqlite3_memory_highwater()] include any overhead
2560** added by SQLite in its implementation of [sqlite3_malloc()],
2561** but not overhead added by the any underlying system library
2562** routines that [sqlite3_malloc()] may call.
2563**
2564** ^The memory high-water mark is reset to the current value of
2565** [sqlite3_memory_used()] if and only if the parameter to
2566** [sqlite3_memory_highwater()] is true. ^The value returned
2567** by [sqlite3_memory_highwater(1)] is the high-water mark
2568** prior to the reset.
2569*/
2570SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_used(void);
2571SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_memory_highwater(int resetFlag);
2572
2573/*
2574** CAPI3REF: Pseudo-Random Number Generator
2575**
2576** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
2577** select random [ROWID | ROWIDs] when inserting new records into a table that
2578** already uses the largest possible [ROWID]. The PRNG is also used for
2579** the build-in random() and randomblob() SQL functions. This interface allows
2580** applications to access the same PRNG for other purposes.
2581**
2582** ^A call to this routine stores N bytes of randomness into buffer P.
2583** ^The P parameter can be a NULL pointer.
2584**
2585** ^If this routine has not been previously called or if the previous
2586** call had N less than one or a NULL pointer for P, then the PRNG is
2587** seeded using randomness obtained from the xRandomness method of
2588** the default [sqlite3_vfs] object.
2589** ^If the previous call to this routine had an N of 1 or more and a
2590** non-NULL P then the pseudo-randomness is generated
2591** internally and without recourse to the [sqlite3_vfs] xRandomness
2592** method.
2593*/
2594SQLITE_API void SQLITE_STDCALL sqlite3_randomness(int N, void *P);
2595
2596/*
2597** CAPI3REF: Compile-Time Authorization Callbacks
2598** METHOD: sqlite3
2599**
2600** ^This routine registers an authorizer callback with a particular
2601** [database connection], supplied in the first argument.
2602** ^The authorizer callback is invoked as SQL statements are being compiled
2603** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
2604** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()]. ^At various
2605** points during the compilation process, as logic is being created
2606** to perform various actions, the authorizer callback is invoked to
2607** see if those actions are allowed. ^The authorizer callback should
2608** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
2609** specific action but allow the SQL statement to continue to be
2610** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
2611** rejected with an error. ^If the authorizer callback returns
2612** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
2613** then the [sqlite3_prepare_v2()] or equivalent call that triggered
2614** the authorizer will fail with an error message.
2615**
2616** When the callback returns [SQLITE_OK], that means the operation
2617** requested is ok. ^When the callback returns [SQLITE_DENY], the
2618** [sqlite3_prepare_v2()] or equivalent call that triggered the
2619** authorizer will fail with an error message explaining that
2620** access is denied.
2621**
2622** ^The first parameter to the authorizer callback is a copy of the third
2623** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
2624** to the callback is an integer [SQLITE_COPY | action code] that specifies
2625** the particular action to be authorized. ^The third through sixth parameters
2626** to the callback are zero-terminated strings that contain additional
2627** details about the action to be authorized.
2628**
2629** ^If the action code is [SQLITE_READ]
2630** and the callback returns [SQLITE_IGNORE] then the
2631** [prepared statement] statement is constructed to substitute
2632** a NULL value in place of the table column that would have
2633** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
2634** return can be used to deny an untrusted user access to individual
2635** columns of a table.
2636** ^If the action code is [SQLITE_DELETE] and the callback returns
2637** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
2638** [truncate optimization] is disabled and all rows are deleted individually.
2639**
2640** An authorizer is used when [sqlite3_prepare | preparing]
2641** SQL statements from an untrusted source, to ensure that the SQL statements
2642** do not try to access data they are not allowed to see, or that they do not
2643** try to execute malicious statements that damage the database. For
2644** example, an application may allow a user to enter arbitrary
2645** SQL queries for evaluation by a database. But the application does
2646** not want the user to be able to make arbitrary changes to the
2647** database. An authorizer could then be put in place while the
2648** user-entered SQL is being [sqlite3_prepare | prepared] that
2649** disallows everything except [SELECT] statements.
2650**
2651** Applications that need to process SQL from untrusted sources
2652** might also consider lowering resource limits using [sqlite3_limit()]
2653** and limiting database size using the [max_page_count] [PRAGMA]
2654** in addition to using an authorizer.
2655**
2656** ^(Only a single authorizer can be in place on a database connection
2657** at a time. Each call to sqlite3_set_authorizer overrides the
2658** previous call.)^ ^Disable the authorizer by installing a NULL callback.
2659** The authorizer is disabled by default.
2660**
2661** The authorizer callback must not do anything that will modify
2662** the database connection that invoked the authorizer callback.
2663** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2664** database connections for the meaning of "modify" in this paragraph.
2665**
2666** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
2667** statement might be re-prepared during [sqlite3_step()] due to a
2668** schema change. Hence, the application should ensure that the
2669** correct authorizer callback remains in place during the [sqlite3_step()].
2670**
2671** ^Note that the authorizer callback is invoked only during
2672** [sqlite3_prepare()] or its variants. Authorization is not
2673** performed during statement evaluation in [sqlite3_step()], unless
2674** as stated in the previous paragraph, sqlite3_step() invokes
2675** sqlite3_prepare_v2() to reprepare a statement after a schema change.
2676*/
2677SQLITE_API int SQLITE_STDCALL sqlite3_set_authorizer(
2678 sqlite3*,
2679 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
2680 void *pUserData
2681);
2682
2683/*
2684** CAPI3REF: Authorizer Return Codes
2685**
2686** The [sqlite3_set_authorizer | authorizer callback function] must
2687** return either [SQLITE_OK] or one of these two constants in order
2688** to signal SQLite whether or not the action is permitted. See the
2689** [sqlite3_set_authorizer | authorizer documentation] for additional
2690** information.
2691**
2692** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
2693** returned from the [sqlite3_vtab_on_conflict()] interface.
2694*/
2695#define SQLITE_DENY 1 /* Abort the SQL statement with an error */
2696#define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
2697
2698/*
2699** CAPI3REF: Authorizer Action Codes
2700**
2701** The [sqlite3_set_authorizer()] interface registers a callback function
2702** that is invoked to authorize certain SQL statement actions. The
2703** second parameter to the callback is an integer code that specifies
2704** what action is being authorized. These are the integer action codes that
2705** the authorizer callback may be passed.
2706**
2707** These action code values signify what kind of operation is to be
2708** authorized. The 3rd and 4th parameters to the authorization
2709** callback function will be parameters or NULL depending on which of these
2710** codes is used as the second parameter. ^(The 5th parameter to the
2711** authorizer callback is the name of the database ("main", "temp",
2712** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
2713** is the name of the inner-most trigger or view that is responsible for
2714** the access attempt or NULL if this access attempt is directly from
2715** top-level SQL code.
2716*/
2717/******************************************* 3rd ************ 4th ***********/
2718#define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
2719#define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
2720#define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
2721#define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
2722#define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
2723#define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
2724#define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
2725#define SQLITE_CREATE_VIEW 8 /* View Name NULL */
2726#define SQLITE_DELETE 9 /* Table Name NULL */
2727#define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
2728#define SQLITE_DROP_TABLE 11 /* Table Name NULL */
2729#define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
2730#define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
2731#define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
2732#define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
2733#define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
2734#define SQLITE_DROP_VIEW 17 /* View Name NULL */
2735#define SQLITE_INSERT 18 /* Table Name NULL */
2736#define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
2737#define SQLITE_READ 20 /* Table Name Column Name */
2738#define SQLITE_SELECT 21 /* NULL NULL */
2739#define SQLITE_TRANSACTION 22 /* Operation NULL */
2740#define SQLITE_UPDATE 23 /* Table Name Column Name */
2741#define SQLITE_ATTACH 24 /* Filename NULL */
2742#define SQLITE_DETACH 25 /* Database Name NULL */
2743#define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
2744#define SQLITE_REINDEX 27 /* Index Name NULL */
2745#define SQLITE_ANALYZE 28 /* Table Name NULL */
2746#define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
2747#define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
2748#define SQLITE_FUNCTION 31 /* NULL Function Name */
2749#define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
2750#define SQLITE_COPY 0 /* No longer used */
2751#define SQLITE_RECURSIVE 33 /* NULL NULL */
2752
2753/*
2754** CAPI3REF: Tracing And Profiling Functions
2755** METHOD: sqlite3
2756**
2757** These routines register callback functions that can be used for
2758** tracing and profiling the execution of SQL statements.
2759**
2760** ^The callback function registered by sqlite3_trace() is invoked at
2761** various times when an SQL statement is being run by [sqlite3_step()].
2762** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
2763** SQL statement text as the statement first begins executing.
2764** ^(Additional sqlite3_trace() callbacks might occur
2765** as each triggered subprogram is entered. The callbacks for triggers
2766** contain a UTF-8 SQL comment that identifies the trigger.)^
2767**
2768** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
2769** the length of [bound parameter] expansion in the output of sqlite3_trace().
2770**
2771** ^The callback function registered by sqlite3_profile() is invoked
2772** as each SQL statement finishes. ^The profile callback contains
2773** the original statement text and an estimate of wall-clock time
2774** of how long that statement took to run. ^The profile callback
2775** time is in units of nanoseconds, however the current implementation
2776** is only capable of millisecond resolution so the six least significant
2777** digits in the time are meaningless. Future versions of SQLite
2778** might provide greater resolution on the profiler callback. The
2779** sqlite3_profile() function is considered experimental and is
2780** subject to change in future versions of SQLite.
2781*/
2782SQLITE_API void *SQLITE_STDCALL sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
2783SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_profile(sqlite3*,
2784 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
2785
2786/*
2787** CAPI3REF: Query Progress Callbacks
2788** METHOD: sqlite3
2789**
2790** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
2791** function X to be invoked periodically during long running calls to
2792** [sqlite3_exec()], [sqlite3_step()] and [sqlite3_get_table()] for
2793** database connection D. An example use for this
2794** interface is to keep a GUI updated during a large query.
2795**
2796** ^The parameter P is passed through as the only parameter to the
2797** callback function X. ^The parameter N is the approximate number of
2798** [virtual machine instructions] that are evaluated between successive
2799** invocations of the callback X. ^If N is less than one then the progress
2800** handler is disabled.
2801**
2802** ^Only a single progress handler may be defined at one time per
2803** [database connection]; setting a new progress handler cancels the
2804** old one. ^Setting parameter X to NULL disables the progress handler.
2805** ^The progress handler is also disabled by setting N to a value less
2806** than 1.
2807**
2808** ^If the progress callback returns non-zero, the operation is
2809** interrupted. This feature can be used to implement a
2810** "Cancel" button on a GUI progress dialog box.
2811**
2812** The progress handler callback must not do anything that will modify
2813** the database connection that invoked the progress handler.
2814** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
2815** database connections for the meaning of "modify" in this paragraph.
2816**
2817*/
2818SQLITE_API void SQLITE_STDCALL sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
2819
2820/*
2821** CAPI3REF: Opening A New Database Connection
2822** CONSTRUCTOR: sqlite3
2823**
2824** ^These routines open an SQLite database file as specified by the
2825** filename argument. ^The filename argument is interpreted as UTF-8 for
2826** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
2827** order for sqlite3_open16(). ^(A [database connection] handle is usually
2828** returned in *ppDb, even if an error occurs. The only exception is that
2829** if SQLite is unable to allocate memory to hold the [sqlite3] object,
2830** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
2831** object.)^ ^(If the database is opened (and/or created) successfully, then
2832** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
2833** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
2834** an English language description of the error following a failure of any
2835** of the sqlite3_open() routines.
2836**
2837** ^The default encoding will be UTF-8 for databases created using
2838** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
2839** created using sqlite3_open16() will be UTF-16 in the native byte order.
2840**
2841** Whether or not an error occurs when it is opened, resources
2842** associated with the [database connection] handle should be released by
2843** passing it to [sqlite3_close()] when it is no longer required.
2844**
2845** The sqlite3_open_v2() interface works like sqlite3_open()
2846** except that it accepts two additional parameters for additional control
2847** over the new database connection. ^(The flags parameter to
2848** sqlite3_open_v2() can take one of
2849** the following three values, optionally combined with the
2850** [SQLITE_OPEN_NOMUTEX], [SQLITE_OPEN_FULLMUTEX], [SQLITE_OPEN_SHAREDCACHE],
2851** [SQLITE_OPEN_PRIVATECACHE], and/or [SQLITE_OPEN_URI] flags:)^
2852**
2853** <dl>
2854** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
2855** <dd>The database is opened in read-only mode. If the database does not
2856** already exist, an error is returned.</dd>)^
2857**
2858** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
2859** <dd>The database is opened for reading and writing if possible, or reading
2860** only if the file is write protected by the operating system. In either
2861** case the database must already exist, otherwise an error is returned.</dd>)^
2862**
2863** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
2864** <dd>The database is opened for reading and writing, and is created if
2865** it does not already exist. This is the behavior that is always used for
2866** sqlite3_open() and sqlite3_open16().</dd>)^
2867** </dl>
2868**
2869** If the 3rd parameter to sqlite3_open_v2() is not one of the
2870** combinations shown above optionally combined with other
2871** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
2872** then the behavior is undefined.
2873**
2874** ^If the [SQLITE_OPEN_NOMUTEX] flag is set, then the database connection
2875** opens in the multi-thread [threading mode] as long as the single-thread
2876** mode has not been set at compile-time or start-time. ^If the
2877** [SQLITE_OPEN_FULLMUTEX] flag is set then the database connection opens
2878** in the serialized [threading mode] unless single-thread was
2879** previously selected at compile-time or start-time.
2880** ^The [SQLITE_OPEN_SHAREDCACHE] flag causes the database connection to be
2881** eligible to use [shared cache mode], regardless of whether or not shared
2882** cache is enabled using [sqlite3_enable_shared_cache()]. ^The
2883** [SQLITE_OPEN_PRIVATECACHE] flag causes the database connection to not
2884** participate in [shared cache mode] even if it is enabled.
2885**
2886** ^The fourth parameter to sqlite3_open_v2() is the name of the
2887** [sqlite3_vfs] object that defines the operating system interface that
2888** the new database connection should use. ^If the fourth parameter is
2889** a NULL pointer then the default [sqlite3_vfs] object is used.
2890**
2891** ^If the filename is ":memory:", then a private, temporary in-memory database
2892** is created for the connection. ^This in-memory database will vanish when
2893** the database connection is closed. Future versions of SQLite might
2894** make use of additional special filenames that begin with the ":" character.
2895** It is recommended that when a database filename actually does begin with
2896** a ":" character you should prefix the filename with a pathname such as
2897** "./" to avoid ambiguity.
2898**
2899** ^If the filename is an empty string, then a private, temporary
2900** on-disk database will be created. ^This private database will be
2901** automatically deleted as soon as the database connection is closed.
2902**
2903** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
2904**
2905** ^If [URI filename] interpretation is enabled, and the filename argument
2906** begins with "file:", then the filename is interpreted as a URI. ^URI
2907** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
2908** set in the fourth argument to sqlite3_open_v2(), or if it has
2909** been enabled globally using the [SQLITE_CONFIG_URI] option with the
2910** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
2911** As of SQLite version 3.7.7, URI filename interpretation is turned off
2912** by default, but future releases of SQLite might enable URI filename
2913** interpretation by default. See "[URI filenames]" for additional
2914** information.
2915**
2916** URI filenames are parsed according to RFC 3986. ^If the URI contains an
2917** authority, then it must be either an empty string or the string
2918** "localhost". ^If the authority is not an empty string or "localhost", an
2919** error is returned to the caller. ^The fragment component of a URI, if
2920** present, is ignored.
2921**
2922** ^SQLite uses the path component of the URI as the name of the disk file
2923** which contains the database. ^If the path begins with a '/' character,
2924** then it is interpreted as an absolute path. ^If the path does not begin
2925** with a '/' (meaning that the authority section is omitted from the URI)
2926** then the path is interpreted as a relative path.
2927** ^(On windows, the first component of an absolute path
2928** is a drive specification (e.g. "C:").)^
2929**
2930** [[core URI query parameters]]
2931** The query component of a URI may contain parameters that are interpreted
2932** either by SQLite itself, or by a [VFS | custom VFS implementation].
2933** SQLite and its built-in [VFSes] interpret the
2934** following query parameters:
2935**
2936** <ul>
2937** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
2938** a VFS object that provides the operating system interface that should
2939** be used to access the database file on disk. ^If this option is set to
2940** an empty string the default VFS object is used. ^Specifying an unknown
2941** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
2942** present, then the VFS specified by the option takes precedence over
2943** the value passed as the fourth parameter to sqlite3_open_v2().
2944**
2945** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
2946** "rwc", or "memory". Attempting to set it to any other value is
2947** an error)^.
2948** ^If "ro" is specified, then the database is opened for read-only
2949** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
2950** third argument to sqlite3_open_v2(). ^If the mode option is set to
2951** "rw", then the database is opened for read-write (but not create)
2952** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
2953** been set. ^Value "rwc" is equivalent to setting both
2954** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
2955** set to "memory" then a pure [in-memory database] that never reads
2956** or writes from disk is used. ^It is an error to specify a value for
2957** the mode parameter that is less restrictive than that specified by
2958** the flags passed in the third parameter to sqlite3_open_v2().
2959**
2960** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
2961** "private". ^Setting it to "shared" is equivalent to setting the
2962** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
2963** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
2964** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
2965** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
2966** a URI filename, its value overrides any behavior requested by setting
2967** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
2968**
2969** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
2970** [powersafe overwrite] property does or does not apply to the
2971** storage media on which the database file resides.
2972**
2973** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
2974** which if set disables file locking in rollback journal modes. This
2975** is useful for accessing a database on a filesystem that does not
2976** support locking. Caution: Database corruption might result if two
2977** or more processes write to the same database and any one of those
2978** processes uses nolock=1.
2979**
2980** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
2981** parameter that indicates that the database file is stored on
2982** read-only media. ^When immutable is set, SQLite assumes that the
2983** database file cannot be changed, even by a process with higher
2984** privilege, and so the database is opened read-only and all locking
2985** and change detection is disabled. Caution: Setting the immutable
2986** property on a database file that does in fact change can result
2987** in incorrect query results and/or [SQLITE_CORRUPT] errors.
2988** See also: [SQLITE_IOCAP_IMMUTABLE].
2989**
2990** </ul>
2991**
2992** ^Specifying an unknown parameter in the query component of a URI is not an
2993** error. Future versions of SQLite might understand additional query
2994** parameters. See "[query parameters with special meaning to SQLite]" for
2995** additional information.
2996**
2997** [[URI filename examples]] <h3>URI filename examples</h3>
2998**
2999** <table border="1" align=center cellpadding=5>
3000** <tr><th> URI filenames <th> Results
3001** <tr><td> file:data.db <td>
3002** Open the file "data.db" in the current directory.
3003** <tr><td> file:/home/fred/data.db<br>
3004** file:///home/fred/data.db <br>
3005** file://localhost/home/fred/data.db <br> <td>
3006** Open the database file "/home/fred/data.db".
3007** <tr><td> file://darkstar/home/fred/data.db <td>
3008** An error. "darkstar" is not a recognized authority.
3009** <tr><td style="white-space:nowrap">
3010** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3011** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3012** C:. Note that the %20 escaping in this example is not strictly
3013** necessary - space characters can be used literally
3014** in URI filenames.
3015** <tr><td> file:data.db?mode=ro&cache=private <td>
3016** Open file "data.db" in the current directory for read-only access.
3017** Regardless of whether or not shared-cache mode is enabled by
3018** default, use a private cache.
3019** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3020** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3021** that uses dot-files in place of posix advisory locking.
3022** <tr><td> file:data.db?mode=readonly <td>
3023** An error. "readonly" is not a valid option for the "mode" parameter.
3024** </table>
3025**
3026** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3027** query components of a URI. A hexadecimal escape sequence consists of a
3028** percent sign - "%" - followed by exactly two hexadecimal digits
3029** specifying an octet value. ^Before the path or query components of a
3030** URI filename are interpreted, they are encoded using UTF-8 and all
3031** hexadecimal escape sequences replaced by a single byte containing the
3032** corresponding octet. If this process generates an invalid UTF-8 encoding,
3033** the results are undefined.
3034**
3035** <b>Note to Windows users:</b> The encoding used for the filename argument
3036** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3037** codepage is currently defined. Filenames containing international
3038** characters must be converted to UTF-8 prior to passing them into
3039** sqlite3_open() or sqlite3_open_v2().
3040**
3041** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3042** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3043** features that require the use of temporary files may fail.
3044**
3045** See also: [sqlite3_temp_directory]
3046*/
3047SQLITE_API int SQLITE_STDCALL sqlite3_open(
3048 const char *filename, /* Database filename (UTF-8) */
3049 sqlite3 **ppDb /* OUT: SQLite db handle */
3050);
3051SQLITE_API int SQLITE_STDCALL sqlite3_open16(
3052 const void *filename, /* Database filename (UTF-16) */
3053 sqlite3 **ppDb /* OUT: SQLite db handle */
3054);
3055SQLITE_API int SQLITE_STDCALL sqlite3_open_v2(
3056 const char *filename, /* Database filename (UTF-8) */
3057 sqlite3 **ppDb, /* OUT: SQLite db handle */
3058 int flags, /* Flags */
3059 const char *zVfs /* Name of VFS module to use */
3060);
3061
3062/*
3063** CAPI3REF: Obtain Values For URI Parameters
3064**
3065** These are utility routines, useful to VFS implementations, that check
3066** to see if a database file was a URI that contained a specific query
3067** parameter, and if so obtains the value of that query parameter.
3068**
3069** If F is the database filename pointer passed into the xOpen() method of
3070** a VFS implementation when the flags parameter to xOpen() has one or
3071** more of the [SQLITE_OPEN_URI] or [SQLITE_OPEN_MAIN_DB] bits set and
3072** P is the name of the query parameter, then
3073** sqlite3_uri_parameter(F,P) returns the value of the P
3074** parameter if it exists or a NULL pointer if P does not appear as a
3075** query parameter on F. If P is a query parameter of F
3076** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3077** a pointer to an empty string.
3078**
3079** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3080** parameter and returns true (1) or false (0) according to the value
3081** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3082** value of query parameter P is one of "yes", "true", or "on" in any
3083** case or if the value begins with a non-zero number. The
3084** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3085** query parameter P is one of "no", "false", or "off" in any case or
3086** if the value begins with a numeric zero. If P is not a query
3087** parameter on F or if the value of P is does not match any of the
3088** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3089**
3090** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3091** 64-bit signed integer and returns that integer, or D if P does not
3092** exist. If the value of P is something other than an integer, then
3093** zero is returned.
3094**
3095** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3096** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3097** is not a database file pathname pointer that SQLite passed into the xOpen
3098** VFS method, then the behavior of this routine is undefined and probably
3099** undesirable.
3100*/
3101SQLITE_API const char *SQLITE_STDCALL sqlite3_uri_parameter(const char *zFilename, const char *zParam);
3102SQLITE_API int SQLITE_STDCALL sqlite3_uri_boolean(const char *zFile, const char *zParam, int bDefault);
3103SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_uri_int64(const char*, const char*, sqlite3_int64);
3104
3105
3106/*
3107** CAPI3REF: Error Codes And Messages
3108** METHOD: sqlite3
3109**
3110** ^If the most recent sqlite3_* API call associated with
3111** [database connection] D failed, then the sqlite3_errcode(D) interface
3112** returns the numeric [result code] or [extended result code] for that
3113** API call.
3114** If the most recent API call was successful,
3115** then the return value from sqlite3_errcode() is undefined.
3116** ^The sqlite3_extended_errcode()
3117** interface is the same except that it always returns the
3118** [extended result code] even when extended result codes are
3119** disabled.
3120**
3121** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3122** text that describes the error, as either UTF-8 or UTF-16 respectively.
3123** ^(Memory to hold the error message string is managed internally.
3124** The application does not need to worry about freeing the result.
3125** However, the error string might be overwritten or deallocated by
3126** subsequent calls to other SQLite interface functions.)^
3127**
3128** ^The sqlite3_errstr() interface returns the English-language text
3129** that describes the [result code], as UTF-8.
3130** ^(Memory to hold the error message string is managed internally
3131** and must not be freed by the application)^.
3132**
3133** When the serialized [threading mode] is in use, it might be the
3134** case that a second error occurs on a separate thread in between
3135** the time of the first error and the call to these interfaces.
3136** When that happens, the second error will be reported since these
3137** interfaces always report the most recent result. To avoid
3138** this, each thread can obtain exclusive use of the [database connection] D
3139** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
3140** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
3141** all calls to the interfaces listed here are completed.
3142**
3143** If an interface fails with SQLITE_MISUSE, that means the interface
3144** was invoked incorrectly by the application. In that case, the
3145** error code and message may or may not be set.
3146*/
3147SQLITE_API int SQLITE_STDCALL sqlite3_errcode(sqlite3 *db);
3148SQLITE_API int SQLITE_STDCALL sqlite3_extended_errcode(sqlite3 *db);
3149SQLITE_API const char *SQLITE_STDCALL sqlite3_errmsg(sqlite3*);
3150SQLITE_API const void *SQLITE_STDCALL sqlite3_errmsg16(sqlite3*);
3151SQLITE_API const char *SQLITE_STDCALL sqlite3_errstr(int);
3152
3153/*
3154** CAPI3REF: Prepared Statement Object
3155** KEYWORDS: {prepared statement} {prepared statements}
3156**
3157** An instance of this object represents a single SQL statement that
3158** has been compiled into binary form and is ready to be evaluated.
3159**
3160** Think of each SQL statement as a separate computer program. The
3161** original SQL text is source code. A prepared statement object
3162** is the compiled object code. All SQL must be converted into a
3163** prepared statement before it can be run.
3164**
3165** The life-cycle of a prepared statement object usually goes like this:
3166**
3167** <ol>
3168** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
3169** <li> Bind values to [parameters] using the sqlite3_bind_*()
3170** interfaces.
3171** <li> Run the SQL by calling [sqlite3_step()] one or more times.
3172** <li> Reset the prepared statement using [sqlite3_reset()] then go back
3173** to step 2. Do this zero or more times.
3174** <li> Destroy the object using [sqlite3_finalize()].
3175** </ol>
3176*/
3177typedef struct sqlite3_stmt sqlite3_stmt;
3178
3179/*
3180** CAPI3REF: Run-time Limits
3181** METHOD: sqlite3
3182**
3183** ^(This interface allows the size of various constructs to be limited
3184** on a connection by connection basis. The first parameter is the
3185** [database connection] whose limit is to be set or queried. The
3186** second parameter is one of the [limit categories] that define a
3187** class of constructs to be size limited. The third parameter is the
3188** new limit for that construct.)^
3189**
3190** ^If the new limit is a negative number, the limit is unchanged.
3191** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
3192** [limits | hard upper bound]
3193** set at compile-time by a C preprocessor macro called
3194** [limits | SQLITE_MAX_<i>NAME</i>].
3195** (The "_LIMIT_" in the name is changed to "_MAX_".))^
3196** ^Attempts to increase a limit above its hard upper bound are
3197** silently truncated to the hard upper bound.
3198**
3199** ^Regardless of whether or not the limit was changed, the
3200** [sqlite3_limit()] interface returns the prior value of the limit.
3201** ^Hence, to find the current value of a limit without changing it,
3202** simply invoke this interface with the third parameter set to -1.
3203**
3204** Run-time limits are intended for use in applications that manage
3205** both their own internal database and also databases that are controlled
3206** by untrusted external sources. An example application might be a
3207** web browser that has its own databases for storing history and
3208** separate databases controlled by JavaScript applications downloaded
3209** off the Internet. The internal databases can be given the
3210** large, default limits. Databases managed by external sources can
3211** be given much smaller limits designed to prevent a denial of service
3212** attack. Developers might also want to use the [sqlite3_set_authorizer()]
3213** interface to further control untrusted SQL. The size of the database
3214** created by an untrusted script can be contained using the
3215** [max_page_count] [PRAGMA].
3216**
3217** New run-time limit categories may be added in future releases.
3218*/
3219SQLITE_API int SQLITE_STDCALL sqlite3_limit(sqlite3*, int id, int newVal);
3220
3221/*
3222** CAPI3REF: Run-Time Limit Categories
3223** KEYWORDS: {limit category} {*limit categories}
3224**
3225** These constants define various performance limits
3226** that can be lowered at run-time using [sqlite3_limit()].
3227** The synopsis of the meanings of the various limits is shown below.
3228** Additional information is available at [limits | Limits in SQLite].
3229**
3230** <dl>
3231** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
3232** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
3233**
3234** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
3235** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
3236**
3237** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
3238** <dd>The maximum number of columns in a table definition or in the
3239** result set of a [SELECT] or the maximum number of columns in an index
3240** or in an ORDER BY or GROUP BY clause.</dd>)^
3241**
3242** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
3243** <dd>The maximum depth of the parse tree on any expression.</dd>)^
3244**
3245** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
3246** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
3247**
3248** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
3249** <dd>The maximum number of instructions in a virtual machine program
3250** used to implement an SQL statement. This limit is not currently
3251** enforced, though that might be added in some future release of
3252** SQLite.</dd>)^
3253**
3254** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
3255** <dd>The maximum number of arguments on a function.</dd>)^
3256**
3257** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
3258** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
3259**
3260** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
3261** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
3262** <dd>The maximum length of the pattern argument to the [LIKE] or
3263** [GLOB] operators.</dd>)^
3264**
3265** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
3266** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
3267** <dd>The maximum index number of any [parameter] in an SQL statement.)^
3268**
3269** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
3270** <dd>The maximum depth of recursion for triggers.</dd>)^
3271**
3272** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
3273** <dd>The maximum number of auxiliary worker threads that a single
3274** [prepared statement] may start.</dd>)^
3275** </dl>
3276*/
3277#define SQLITE_LIMIT_LENGTH 0
3278#define SQLITE_LIMIT_SQL_LENGTH 1
3279#define SQLITE_LIMIT_COLUMN 2
3280#define SQLITE_LIMIT_EXPR_DEPTH 3
3281#define SQLITE_LIMIT_COMPOUND_SELECT 4
3282#define SQLITE_LIMIT_VDBE_OP 5
3283#define SQLITE_LIMIT_FUNCTION_ARG 6
3284#define SQLITE_LIMIT_ATTACHED 7
3285#define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
3286#define SQLITE_LIMIT_VARIABLE_NUMBER 9
3287#define SQLITE_LIMIT_TRIGGER_DEPTH 10
3288#define SQLITE_LIMIT_WORKER_THREADS 11
3289
3290/*
3291** CAPI3REF: Compiling An SQL Statement
3292** KEYWORDS: {SQL statement compiler}
3293** METHOD: sqlite3
3294** CONSTRUCTOR: sqlite3_stmt
3295**
3296** To execute an SQL query, it must first be compiled into a byte-code
3297** program using one of these routines.
3298**
3299** The first argument, "db", is a [database connection] obtained from a
3300** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
3301** [sqlite3_open16()]. The database connection must not have been closed.
3302**
3303** The second argument, "zSql", is the statement to be compiled, encoded
3304** as either UTF-8 or UTF-16. The sqlite3_prepare() and sqlite3_prepare_v2()
3305** interfaces use UTF-8, and sqlite3_prepare16() and sqlite3_prepare16_v2()
3306** use UTF-16.
3307**
3308** ^If the nByte argument is negative, then zSql is read up to the
3309** first zero terminator. ^If nByte is positive, then it is the
3310** number of bytes read from zSql. ^If nByte is zero, then no prepared
3311** statement is generated.
3312** If the caller knows that the supplied string is nul-terminated, then
3313** there is a small performance advantage to passing an nByte parameter that
3314** is the number of bytes in the input string <i>including</i>
3315** the nul-terminator.
3316**
3317** ^If pzTail is not NULL then *pzTail is made to point to the first byte
3318** past the end of the first SQL statement in zSql. These routines only
3319** compile the first statement in zSql, so *pzTail is left pointing to
3320** what remains uncompiled.
3321**
3322** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
3323** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
3324** to NULL. ^If the input text contains no SQL (if the input is an empty
3325** string or a comment) then *ppStmt is set to NULL.
3326** The calling procedure is responsible for deleting the compiled
3327** SQL statement using [sqlite3_finalize()] after it has finished with it.
3328** ppStmt may not be NULL.
3329**
3330** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
3331** otherwise an [error code] is returned.
3332**
3333** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
3334** recommended for all new programs. The two older interfaces are retained
3335** for backwards compatibility, but their use is discouraged.
3336** ^In the "v2" interfaces, the prepared statement
3337** that is returned (the [sqlite3_stmt] object) contains a copy of the
3338** original SQL text. This causes the [sqlite3_step()] interface to
3339** behave differently in three ways:
3340**
3341** <ol>
3342** <li>
3343** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
3344** always used to do, [sqlite3_step()] will automatically recompile the SQL
3345** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
3346** retries will occur before sqlite3_step() gives up and returns an error.
3347** </li>
3348**
3349** <li>
3350** ^When an error occurs, [sqlite3_step()] will return one of the detailed
3351** [error codes] or [extended error codes]. ^The legacy behavior was that
3352** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
3353** and the application would have to make a second call to [sqlite3_reset()]
3354** in order to find the underlying cause of the problem. With the "v2" prepare
3355** interfaces, the underlying reason for the error is returned immediately.
3356** </li>
3357**
3358** <li>
3359** ^If the specific value bound to [parameter | host parameter] in the
3360** WHERE clause might influence the choice of query plan for a statement,
3361** then the statement will be automatically recompiled, as if there had been
3362** a schema change, on the first [sqlite3_step()] call following any change
3363** to the [sqlite3_bind_text | bindings] of that [parameter].
3364** ^The specific value of WHERE-clause [parameter] might influence the
3365** choice of query plan if the parameter is the left-hand side of a [LIKE]
3366** or [GLOB] operator or if the parameter is compared to an indexed column
3367** and the [SQLITE_ENABLE_STAT3] compile-time option is enabled.
3368** </li>
3369** </ol>
3370*/
3371SQLITE_API int SQLITE_STDCALL sqlite3_prepare(
3372 sqlite3 *db, /* Database handle */
3373 const char *zSql, /* SQL statement, UTF-8 encoded */
3374 int nByte, /* Maximum length of zSql in bytes. */
3375 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3376 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3377);
3378SQLITE_API int SQLITE_STDCALL sqlite3_prepare_v2(
3379 sqlite3 *db, /* Database handle */
3380 const char *zSql, /* SQL statement, UTF-8 encoded */
3381 int nByte, /* Maximum length of zSql in bytes. */
3382 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3383 const char **pzTail /* OUT: Pointer to unused portion of zSql */
3384);
3385SQLITE_API int SQLITE_STDCALL sqlite3_prepare16(
3386 sqlite3 *db, /* Database handle */
3387 const void *zSql, /* SQL statement, UTF-16 encoded */
3388 int nByte, /* Maximum length of zSql in bytes. */
3389 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3390 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3391);
3392SQLITE_API int SQLITE_STDCALL sqlite3_prepare16_v2(
3393 sqlite3 *db, /* Database handle */
3394 const void *zSql, /* SQL statement, UTF-16 encoded */
3395 int nByte, /* Maximum length of zSql in bytes. */
3396 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
3397 const void **pzTail /* OUT: Pointer to unused portion of zSql */
3398);
3399
3400/*
3401** CAPI3REF: Retrieving Statement SQL
3402** METHOD: sqlite3_stmt
3403**
3404** ^This interface can be used to retrieve a saved copy of the original
3405** SQL text used to create a [prepared statement] if that statement was
3406** compiled using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()].
3407*/
3408SQLITE_API const char *SQLITE_STDCALL sqlite3_sql(sqlite3_stmt *pStmt);
3409
3410/*
3411** CAPI3REF: Determine If An SQL Statement Writes The Database
3412** METHOD: sqlite3_stmt
3413**
3414** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
3415** and only if the [prepared statement] X makes no direct changes to
3416** the content of the database file.
3417**
3418** Note that [application-defined SQL functions] or
3419** [virtual tables] might change the database indirectly as a side effect.
3420** ^(For example, if an application defines a function "eval()" that
3421** calls [sqlite3_exec()], then the following SQL statement would
3422** change the database file through side-effects:
3423**
3424** <blockquote><pre>
3425** SELECT eval('DELETE FROM t1') FROM t2;
3426** </pre></blockquote>
3427**
3428** But because the [SELECT] statement does not change the database file
3429** directly, sqlite3_stmt_readonly() would still return true.)^
3430**
3431** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
3432** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
3433** since the statements themselves do not actually modify the database but
3434** rather they control the timing of when other statements modify the
3435** database. ^The [ATTACH] and [DETACH] statements also cause
3436** sqlite3_stmt_readonly() to return true since, while those statements
3437** change the configuration of a database connection, they do not make
3438** changes to the content of the database files on disk.
3439*/
3440SQLITE_API int SQLITE_STDCALL sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
3441
3442/*
3443** CAPI3REF: Determine If A Prepared Statement Has Been Reset
3444** METHOD: sqlite3_stmt
3445**
3446** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
3447** [prepared statement] S has been stepped at least once using
3448** [sqlite3_step(S)] but has neither run to completion (returned
3449** [SQLITE_DONE] from [sqlite3_step(S)]) nor
3450** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
3451** interface returns false if S is a NULL pointer. If S is not a
3452** NULL pointer and is not a pointer to a valid [prepared statement]
3453** object, then the behavior is undefined and probably undesirable.
3454**
3455** This interface can be used in combination [sqlite3_next_stmt()]
3456** to locate all prepared statements associated with a database
3457** connection that are in need of being reset. This can be used,
3458** for example, in diagnostic routines to search for prepared
3459** statements that are holding a transaction open.
3460*/
3461SQLITE_API int SQLITE_STDCALL sqlite3_stmt_busy(sqlite3_stmt*);
3462
3463/*
3464** CAPI3REF: Dynamically Typed Value Object
3465** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
3466**
3467** SQLite uses the sqlite3_value object to represent all values
3468** that can be stored in a database table. SQLite uses dynamic typing
3469** for the values it stores. ^Values stored in sqlite3_value objects
3470** can be integers, floating point values, strings, BLOBs, or NULL.
3471**
3472** An sqlite3_value object may be either "protected" or "unprotected".
3473** Some interfaces require a protected sqlite3_value. Other interfaces
3474** will accept either a protected or an unprotected sqlite3_value.
3475** Every interface that accepts sqlite3_value arguments specifies
3476** whether or not it requires a protected sqlite3_value. The
3477** [sqlite3_value_dup()] interface can be used to construct a new
3478** protected sqlite3_value from an unprotected sqlite3_value.
3479**
3480** The terms "protected" and "unprotected" refer to whether or not
3481** a mutex is held. An internal mutex is held for a protected
3482** sqlite3_value object but no mutex is held for an unprotected
3483** sqlite3_value object. If SQLite is compiled to be single-threaded
3484** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
3485** or if SQLite is run in one of reduced mutex modes
3486** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
3487** then there is no distinction between protected and unprotected
3488** sqlite3_value objects and they can be used interchangeably. However,
3489** for maximum code portability it is recommended that applications
3490** still make the distinction between protected and unprotected
3491** sqlite3_value objects even when not strictly required.
3492**
3493** ^The sqlite3_value objects that are passed as parameters into the
3494** implementation of [application-defined SQL functions] are protected.
3495** ^The sqlite3_value object returned by
3496** [sqlite3_column_value()] is unprotected.
3497** Unprotected sqlite3_value objects may only be used with
3498** [sqlite3_result_value()] and [sqlite3_bind_value()].
3499** The [sqlite3_value_blob | sqlite3_value_type()] family of
3500** interfaces require protected sqlite3_value objects.
3501*/
3502typedef struct Mem sqlite3_value;
3503
3504/*
3505** CAPI3REF: SQL Function Context Object
3506**
3507** The context in which an SQL function executes is stored in an
3508** sqlite3_context object. ^A pointer to an sqlite3_context object
3509** is always first parameter to [application-defined SQL functions].
3510** The application-defined SQL function implementation will pass this
3511** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
3512** [sqlite3_aggregate_context()], [sqlite3_user_data()],
3513** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
3514** and/or [sqlite3_set_auxdata()].
3515*/
3516typedef struct sqlite3_context sqlite3_context;
3517
3518/*
3519** CAPI3REF: Binding Values To Prepared Statements
3520** KEYWORDS: {host parameter} {host parameters} {host parameter name}
3521** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
3522** METHOD: sqlite3_stmt
3523**
3524** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
3525** literals may be replaced by a [parameter] that matches one of following
3526** templates:
3527**
3528** <ul>
3529** <li> ?
3530** <li> ?NNN
3531** <li> :VVV
3532** <li> @VVV
3533** <li> $VVV
3534** </ul>
3535**
3536** In the templates above, NNN represents an integer literal,
3537** and VVV represents an alphanumeric identifier.)^ ^The values of these
3538** parameters (also called "host parameter names" or "SQL parameters")
3539** can be set using the sqlite3_bind_*() routines defined here.
3540**
3541** ^The first argument to the sqlite3_bind_*() routines is always
3542** a pointer to the [sqlite3_stmt] object returned from
3543** [sqlite3_prepare_v2()] or its variants.
3544**
3545** ^The second argument is the index of the SQL parameter to be set.
3546** ^The leftmost SQL parameter has an index of 1. ^When the same named
3547** SQL parameter is used more than once, second and subsequent
3548** occurrences have the same index as the first occurrence.
3549** ^The index for named parameters can be looked up using the
3550** [sqlite3_bind_parameter_index()] API if desired. ^The index
3551** for "?NNN" parameters is the value of NNN.
3552** ^The NNN value must be between 1 and the [sqlite3_limit()]
3553** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 999).
3554**
3555** ^The third argument is the value to bind to the parameter.
3556** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3557** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
3558** is ignored and the end result is the same as sqlite3_bind_null().
3559**
3560** ^(In those routines that have a fourth argument, its value is the
3561** number of bytes in the parameter. To be clear: the value is the
3562** number of <u>bytes</u> in the value, not the number of characters.)^
3563** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
3564** is negative, then the length of the string is
3565** the number of bytes up to the first zero terminator.
3566** If the fourth parameter to sqlite3_bind_blob() is negative, then
3567** the behavior is undefined.
3568** If a non-negative fourth parameter is provided to sqlite3_bind_text()
3569** or sqlite3_bind_text16() or sqlite3_bind_text64() then
3570** that parameter must be the byte offset
3571** where the NUL terminator would occur assuming the string were NUL
3572** terminated. If any NUL characters occur at byte offsets less than
3573** the value of the fourth parameter then the resulting string value will
3574** contain embedded NULs. The result of expressions involving strings
3575** with embedded NULs is undefined.
3576**
3577** ^The fifth argument to the BLOB and string binding interfaces
3578** is a destructor used to dispose of the BLOB or
3579** string after SQLite has finished with it. ^The destructor is called
3580** to dispose of the BLOB or string even if the call to bind API fails.
3581** ^If the fifth argument is
3582** the special value [SQLITE_STATIC], then SQLite assumes that the
3583** information is in static, unmanaged space and does not need to be freed.
3584** ^If the fifth argument has the value [SQLITE_TRANSIENT], then
3585** SQLite makes its own private copy of the data immediately, before
3586** the sqlite3_bind_*() routine returns.
3587**
3588** ^The sixth argument to sqlite3_bind_text64() must be one of
3589** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
3590** to specify the encoding of the text in the third parameter. If
3591** the sixth argument to sqlite3_bind_text64() is not one of the
3592** allowed values shown above, or if the text encoding is different
3593** from the encoding specified by the sixth parameter, then the behavior
3594** is undefined.
3595**
3596** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
3597** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
3598** (just an integer to hold its size) while it is being processed.
3599** Zeroblobs are intended to serve as placeholders for BLOBs whose
3600** content is later written using
3601** [sqlite3_blob_open | incremental BLOB I/O] routines.
3602** ^A negative value for the zeroblob results in a zero-length BLOB.
3603**
3604** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
3605** for the [prepared statement] or with a prepared statement for which
3606** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
3607** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
3608** routine is passed a [prepared statement] that has been finalized, the
3609** result is undefined and probably harmful.
3610**
3611** ^Bindings are not cleared by the [sqlite3_reset()] routine.
3612** ^Unbound parameters are interpreted as NULL.
3613**
3614** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
3615** [error code] if anything goes wrong.
3616** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
3617** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
3618** [SQLITE_MAX_LENGTH].
3619** ^[SQLITE_RANGE] is returned if the parameter
3620** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
3621**
3622** See also: [sqlite3_bind_parameter_count()],
3623** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
3624*/
3625SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
3626SQLITE_API int SQLITE_STDCALL sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
3627 void(*)(void*));
3628SQLITE_API int SQLITE_STDCALL sqlite3_bind_double(sqlite3_stmt*, int, double);
3629SQLITE_API int SQLITE_STDCALL sqlite3_bind_int(sqlite3_stmt*, int, int);
3630SQLITE_API int SQLITE_STDCALL sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
3631SQLITE_API int SQLITE_STDCALL sqlite3_bind_null(sqlite3_stmt*, int);
3632SQLITE_API int SQLITE_STDCALL sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
3633SQLITE_API int SQLITE_STDCALL sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
3634SQLITE_API int SQLITE_STDCALL sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
3635 void(*)(void*), unsigned char encoding);
3636SQLITE_API int SQLITE_STDCALL sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
3637SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
3638SQLITE_API int SQLITE_STDCALL sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
3639
3640/*
3641** CAPI3REF: Number Of SQL Parameters
3642** METHOD: sqlite3_stmt
3643**
3644** ^This routine can be used to find the number of [SQL parameters]
3645** in a [prepared statement]. SQL parameters are tokens of the
3646** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
3647** placeholders for values that are [sqlite3_bind_blob | bound]
3648** to the parameters at a later time.
3649**
3650** ^(This routine actually returns the index of the largest (rightmost)
3651** parameter. For all forms except ?NNN, this will correspond to the
3652** number of unique parameters. If parameters of the ?NNN form are used,
3653** there may be gaps in the list.)^
3654**
3655** See also: [sqlite3_bind_blob|sqlite3_bind()],
3656** [sqlite3_bind_parameter_name()], and
3657** [sqlite3_bind_parameter_index()].
3658*/
3659SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_count(sqlite3_stmt*);
3660
3661/*
3662** CAPI3REF: Name Of A Host Parameter
3663** METHOD: sqlite3_stmt
3664**
3665** ^The sqlite3_bind_parameter_name(P,N) interface returns
3666** the name of the N-th [SQL parameter] in the [prepared statement] P.
3667** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
3668** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
3669** respectively.
3670** In other words, the initial ":" or "$" or "@" or "?"
3671** is included as part of the name.)^
3672** ^Parameters of the form "?" without a following integer have no name
3673** and are referred to as "nameless" or "anonymous parameters".
3674**
3675** ^The first host parameter has an index of 1, not 0.
3676**
3677** ^If the value N is out of range or if the N-th parameter is
3678** nameless, then NULL is returned. ^The returned string is
3679** always in UTF-8 encoding even if the named parameter was
3680** originally specified as UTF-16 in [sqlite3_prepare16()] or
3681** [sqlite3_prepare16_v2()].
3682**
3683** See also: [sqlite3_bind_blob|sqlite3_bind()],
3684** [sqlite3_bind_parameter_count()], and
3685** [sqlite3_bind_parameter_index()].
3686*/
3687SQLITE_API const char *SQLITE_STDCALL sqlite3_bind_parameter_name(sqlite3_stmt*, int);
3688
3689/*
3690** CAPI3REF: Index Of A Parameter With A Given Name
3691** METHOD: sqlite3_stmt
3692**
3693** ^Return the index of an SQL parameter given its name. ^The
3694** index value returned is suitable for use as the second
3695** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
3696** is returned if no matching parameter is found. ^The parameter
3697** name must be given in UTF-8 even if the original statement
3698** was prepared from UTF-16 text using [sqlite3_prepare16_v2()].
3699**
3700** See also: [sqlite3_bind_blob|sqlite3_bind()],
3701** [sqlite3_bind_parameter_count()], and
3702** [sqlite3_bind_parameter_name()].
3703*/
3704SQLITE_API int SQLITE_STDCALL sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
3705
3706/*
3707** CAPI3REF: Reset All Bindings On A Prepared Statement
3708** METHOD: sqlite3_stmt
3709**
3710** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
3711** the [sqlite3_bind_blob | bindings] on a [prepared statement].
3712** ^Use this routine to reset all host parameters to NULL.
3713*/
3714SQLITE_API int SQLITE_STDCALL sqlite3_clear_bindings(sqlite3_stmt*);
3715
3716/*
3717** CAPI3REF: Number Of Columns In A Result Set
3718** METHOD: sqlite3_stmt
3719**
3720** ^Return the number of columns in the result set returned by the
3721** [prepared statement]. ^This routine returns 0 if pStmt is an SQL
3722** statement that does not return data (for example an [UPDATE]).
3723**
3724** See also: [sqlite3_data_count()]
3725*/
3726SQLITE_API int SQLITE_STDCALL sqlite3_column_count(sqlite3_stmt *pStmt);
3727
3728/*
3729** CAPI3REF: Column Names In A Result Set
3730** METHOD: sqlite3_stmt
3731**
3732** ^These routines return the name assigned to a particular column
3733** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
3734** interface returns a pointer to a zero-terminated UTF-8 string
3735** and sqlite3_column_name16() returns a pointer to a zero-terminated
3736** UTF-16 string. ^The first parameter is the [prepared statement]
3737** that implements the [SELECT] statement. ^The second parameter is the
3738** column number. ^The leftmost column is number 0.
3739**
3740** ^The returned string pointer is valid until either the [prepared statement]
3741** is destroyed by [sqlite3_finalize()] or until the statement is automatically
3742** reprepared by the first call to [sqlite3_step()] for a particular run
3743** or until the next call to
3744** sqlite3_column_name() or sqlite3_column_name16() on the same column.
3745**
3746** ^If sqlite3_malloc() fails during the processing of either routine
3747** (for example during a conversion from UTF-8 to UTF-16) then a
3748** NULL pointer is returned.
3749**
3750** ^The name of a result column is the value of the "AS" clause for
3751** that column, if there is an AS clause. If there is no AS clause
3752** then the name of the column is unspecified and may change from
3753** one release of SQLite to the next.
3754*/
3755SQLITE_API const char *SQLITE_STDCALL sqlite3_column_name(sqlite3_stmt*, int N);
3756SQLITE_API const void *SQLITE_STDCALL sqlite3_column_name16(sqlite3_stmt*, int N);
3757
3758/*
3759** CAPI3REF: Source Of Data In A Query Result
3760** METHOD: sqlite3_stmt
3761**
3762** ^These routines provide a means to determine the database, table, and
3763** table column that is the origin of a particular result column in
3764** [SELECT] statement.
3765** ^The name of the database or table or column can be returned as
3766** either a UTF-8 or UTF-16 string. ^The _database_ routines return
3767** the database name, the _table_ routines return the table name, and
3768** the origin_ routines return the column name.
3769** ^The returned string is valid until the [prepared statement] is destroyed
3770** using [sqlite3_finalize()] or until the statement is automatically
3771** reprepared by the first call to [sqlite3_step()] for a particular run
3772** or until the same information is requested
3773** again in a different encoding.
3774**
3775** ^The names returned are the original un-aliased names of the
3776** database, table, and column.
3777**
3778** ^The first argument to these interfaces is a [prepared statement].
3779** ^These functions return information about the Nth result column returned by
3780** the statement, where N is the second function argument.
3781** ^The left-most column is column 0 for these routines.
3782**
3783** ^If the Nth column returned by the statement is an expression or
3784** subquery and is not a column value, then all of these functions return
3785** NULL. ^These routine might also return NULL if a memory allocation error
3786** occurs. ^Otherwise, they return the name of the attached database, table,
3787** or column that query result column was extracted from.
3788**
3789** ^As with all other SQLite APIs, those whose names end with "16" return
3790** UTF-16 encoded strings and the other functions return UTF-8.
3791**
3792** ^These APIs are only available if the library was compiled with the
3793** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
3794**
3795** If two or more threads call one or more of these routines against the same
3796** prepared statement and column at the same time then the results are
3797** undefined.
3798**
3799** If two or more threads call one or more
3800** [sqlite3_column_database_name | column metadata interfaces]
3801** for the same [prepared statement] and result column
3802** at the same time then the results are undefined.
3803*/
3804SQLITE_API const char *SQLITE_STDCALL sqlite3_column_database_name(sqlite3_stmt*,int);
3805SQLITE_API const void *SQLITE_STDCALL sqlite3_column_database_name16(sqlite3_stmt*,int);
3806SQLITE_API const char *SQLITE_STDCALL sqlite3_column_table_name(sqlite3_stmt*,int);
3807SQLITE_API const void *SQLITE_STDCALL sqlite3_column_table_name16(sqlite3_stmt*,int);
3808SQLITE_API const char *SQLITE_STDCALL sqlite3_column_origin_name(sqlite3_stmt*,int);
3809SQLITE_API const void *SQLITE_STDCALL sqlite3_column_origin_name16(sqlite3_stmt*,int);
3810
3811/*
3812** CAPI3REF: Declared Datatype Of A Query Result
3813** METHOD: sqlite3_stmt
3814**
3815** ^(The first parameter is a [prepared statement].
3816** If this statement is a [SELECT] statement and the Nth column of the
3817** returned result set of that [SELECT] is a table column (not an
3818** expression or subquery) then the declared type of the table
3819** column is returned.)^ ^If the Nth column of the result set is an
3820** expression or subquery, then a NULL pointer is returned.
3821** ^The returned string is always UTF-8 encoded.
3822**
3823** ^(For example, given the database schema:
3824**
3825** CREATE TABLE t1(c1 VARIANT);
3826**
3827** and the following statement to be compiled:
3828**
3829** SELECT c1 + 1, c1 FROM t1;
3830**
3831** this routine would return the string "VARIANT" for the second result
3832** column (i==1), and a NULL pointer for the first result column (i==0).)^
3833**
3834** ^SQLite uses dynamic run-time typing. ^So just because a column
3835** is declared to contain a particular type does not mean that the
3836** data stored in that column is of the declared type. SQLite is
3837** strongly typed, but the typing is dynamic not static. ^Type
3838** is associated with individual values, not with the containers
3839** used to hold those values.
3840*/
3841SQLITE_API const char *SQLITE_STDCALL sqlite3_column_decltype(sqlite3_stmt*,int);
3842SQLITE_API const void *SQLITE_STDCALL sqlite3_column_decltype16(sqlite3_stmt*,int);
3843
3844/*
3845** CAPI3REF: Evaluate An SQL Statement
3846** METHOD: sqlite3_stmt
3847**
3848** After a [prepared statement] has been prepared using either
3849** [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or one of the legacy
3850** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
3851** must be called one or more times to evaluate the statement.
3852**
3853** The details of the behavior of the sqlite3_step() interface depend
3854** on whether the statement was prepared using the newer "v2" interface
3855** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
3856** interface [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
3857** new "v2" interface is recommended for new applications but the legacy
3858** interface will continue to be supported.
3859**
3860** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
3861** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
3862** ^With the "v2" interface, any of the other [result codes] or
3863** [extended result codes] might be returned as well.
3864**
3865** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
3866** database locks it needs to do its job. ^If the statement is a [COMMIT]
3867** or occurs outside of an explicit transaction, then you can retry the
3868** statement. If the statement is not a [COMMIT] and occurs within an
3869** explicit transaction then you should rollback the transaction before
3870** continuing.
3871**
3872** ^[SQLITE_DONE] means that the statement has finished executing
3873** successfully. sqlite3_step() should not be called again on this virtual
3874** machine without first calling [sqlite3_reset()] to reset the virtual
3875** machine back to its initial state.
3876**
3877** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
3878** is returned each time a new row of data is ready for processing by the
3879** caller. The values may be accessed using the [column access functions].
3880** sqlite3_step() is called again to retrieve the next row of data.
3881**
3882** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
3883** violation) has occurred. sqlite3_step() should not be called again on
3884** the VM. More information may be found by calling [sqlite3_errmsg()].
3885** ^With the legacy interface, a more specific error code (for example,
3886** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
3887** can be obtained by calling [sqlite3_reset()] on the
3888** [prepared statement]. ^In the "v2" interface,
3889** the more specific error code is returned directly by sqlite3_step().
3890**
3891** [SQLITE_MISUSE] means that the this routine was called inappropriately.
3892** Perhaps it was called on a [prepared statement] that has
3893** already been [sqlite3_finalize | finalized] or on one that had
3894** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
3895** be the case that the same database connection is being used by two or
3896** more threads at the same moment in time.
3897**
3898** For all versions of SQLite up to and including 3.6.23.1, a call to
3899** [sqlite3_reset()] was required after sqlite3_step() returned anything
3900** other than [SQLITE_ROW] before any subsequent invocation of
3901** sqlite3_step(). Failure to reset the prepared statement using
3902** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
3903** sqlite3_step(). But after version 3.6.23.1, sqlite3_step() began
3904** calling [sqlite3_reset()] automatically in this circumstance rather
3905** than returning [SQLITE_MISUSE]. This is not considered a compatibility
3906** break because any application that ever receives an SQLITE_MISUSE error
3907** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
3908** can be used to restore the legacy behavior.
3909**
3910** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
3911** API always returns a generic error code, [SQLITE_ERROR], following any
3912** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
3913** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
3914** specific [error codes] that better describes the error.
3915** We admit that this is a goofy design. The problem has been fixed
3916** with the "v2" interface. If you prepare all of your SQL statements
3917** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
3918** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
3919** then the more specific [error codes] are returned directly
3920** by sqlite3_step(). The use of the "v2" interface is recommended.
3921*/
3922SQLITE_API int SQLITE_STDCALL sqlite3_step(sqlite3_stmt*);
3923
3924/*
3925** CAPI3REF: Number of columns in a result set
3926** METHOD: sqlite3_stmt
3927**
3928** ^The sqlite3_data_count(P) interface returns the number of columns in the
3929** current row of the result set of [prepared statement] P.
3930** ^If prepared statement P does not have results ready to return
3931** (via calls to the [sqlite3_column_int | sqlite3_column_*()] of
3932** interfaces) then sqlite3_data_count(P) returns 0.
3933** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
3934** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
3935** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
3936** will return non-zero if previous call to [sqlite3_step](P) returned
3937** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
3938** where it always returns zero since each step of that multi-step
3939** pragma returns 0 columns of data.
3940**
3941** See also: [sqlite3_column_count()]
3942*/
3943SQLITE_API int SQLITE_STDCALL sqlite3_data_count(sqlite3_stmt *pStmt);
3944
3945/*
3946** CAPI3REF: Fundamental Datatypes
3947** KEYWORDS: SQLITE_TEXT
3948**
3949** ^(Every value in SQLite has one of five fundamental datatypes:
3950**
3951** <ul>
3952** <li> 64-bit signed integer
3953** <li> 64-bit IEEE floating point number
3954** <li> string
3955** <li> BLOB
3956** <li> NULL
3957** </ul>)^
3958**
3959** These constants are codes for each of those types.
3960**
3961** Note that the SQLITE_TEXT constant was also used in SQLite version 2
3962** for a completely different meaning. Software that links against both
3963** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
3964** SQLITE_TEXT.
3965*/
3966#define SQLITE_INTEGER 1
3967#define SQLITE_FLOAT 2
3968#define SQLITE_BLOB 4
3969#define SQLITE_NULL 5
3970#ifdef SQLITE_TEXT
3971# undef SQLITE_TEXT
3972#else
3973# define SQLITE_TEXT 3
3974#endif
3975#define SQLITE3_TEXT 3
3976
3977/*
3978** CAPI3REF: Result Values From A Query
3979** KEYWORDS: {column access functions}
3980** METHOD: sqlite3_stmt
3981**
3982** ^These routines return information about a single column of the current
3983** result row of a query. ^In every case the first argument is a pointer
3984** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
3985** that was returned from [sqlite3_prepare_v2()] or one of its variants)
3986** and the second argument is the index of the column for which information
3987** should be returned. ^The leftmost column of the result set has the index 0.
3988** ^The number of columns in the result can be determined using
3989** [sqlite3_column_count()].
3990**
3991** If the SQL statement does not currently point to a valid row, or if the
3992** column index is out of range, the result is undefined.
3993** These routines may only be called when the most recent call to
3994** [sqlite3_step()] has returned [SQLITE_ROW] and neither
3995** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
3996** If any of these routines are called after [sqlite3_reset()] or
3997** [sqlite3_finalize()] or after [sqlite3_step()] has returned
3998** something other than [SQLITE_ROW], the results are undefined.
3999** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
4000** are called from a different thread while any of these routines
4001** are pending, then the results are undefined.
4002**
4003** ^The sqlite3_column_type() routine returns the
4004** [SQLITE_INTEGER | datatype code] for the initial data type
4005** of the result column. ^The returned value is one of [SQLITE_INTEGER],
4006** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL]. The value
4007** returned by sqlite3_column_type() is only meaningful if no type
4008** conversions have occurred as described below. After a type conversion,
4009** the value returned by sqlite3_column_type() is undefined. Future
4010** versions of SQLite may change the behavior of sqlite3_column_type()
4011** following a type conversion.
4012**
4013** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
4014** routine returns the number of bytes in that BLOB or string.
4015** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
4016** the string to UTF-8 and then returns the number of bytes.
4017** ^If the result is a numeric value then sqlite3_column_bytes() uses
4018** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
4019** the number of bytes in that string.
4020** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
4021**
4022** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
4023** routine returns the number of bytes in that BLOB or string.
4024** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
4025** the string to UTF-16 and then returns the number of bytes.
4026** ^If the result is a numeric value then sqlite3_column_bytes16() uses
4027** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
4028** the number of bytes in that string.
4029** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
4030**
4031** ^The values returned by [sqlite3_column_bytes()] and
4032** [sqlite3_column_bytes16()] do not include the zero terminators at the end
4033** of the string. ^For clarity: the values returned by
4034** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
4035** bytes in the string, not the number of characters.
4036**
4037** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
4038** even empty strings, are always zero-terminated. ^The return
4039** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
4040**
4041** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
4042** [unprotected sqlite3_value] object. In a multithreaded environment,
4043** an unprotected sqlite3_value object may only be used safely with
4044** [sqlite3_bind_value()] and [sqlite3_result_value()].
4045** If the [unprotected sqlite3_value] object returned by
4046** [sqlite3_column_value()] is used in any other way, including calls
4047** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
4048** or [sqlite3_value_bytes()], the behavior is not threadsafe.
4049**
4050** These routines attempt to convert the value where appropriate. ^For
4051** example, if the internal representation is FLOAT and a text result
4052** is requested, [sqlite3_snprintf()] is used internally to perform the
4053** conversion automatically. ^(The following table details the conversions
4054** that are applied:
4055**
4056** <blockquote>
4057** <table border="1">
4058** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
4059**
4060** <tr><td> NULL <td> INTEGER <td> Result is 0
4061** <tr><td> NULL <td> FLOAT <td> Result is 0.0
4062** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
4063** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
4064** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
4065** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
4066** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
4067** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
4068** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
4069** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
4070** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
4071** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
4072** <tr><td> TEXT <td> BLOB <td> No change
4073** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
4074** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
4075** <tr><td> BLOB <td> TEXT <td> Add a zero terminator if needed
4076** </table>
4077** </blockquote>)^
4078**
4079** Note that when type conversions occur, pointers returned by prior
4080** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
4081** sqlite3_column_text16() may be invalidated.
4082** Type conversions and pointer invalidations might occur
4083** in the following cases:
4084**
4085** <ul>
4086** <li> The initial content is a BLOB and sqlite3_column_text() or
4087** sqlite3_column_text16() is called. A zero-terminator might
4088** need to be added to the string.</li>
4089** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
4090** sqlite3_column_text16() is called. The content must be converted
4091** to UTF-16.</li>
4092** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
4093** sqlite3_column_text() is called. The content must be converted
4094** to UTF-8.</li>
4095** </ul>
4096**
4097** ^Conversions between UTF-16be and UTF-16le are always done in place and do
4098** not invalidate a prior pointer, though of course the content of the buffer
4099** that the prior pointer references will have been modified. Other kinds
4100** of conversion are done in place when it is possible, but sometimes they
4101** are not possible and in those cases prior pointers are invalidated.
4102**
4103** The safest policy is to invoke these routines
4104** in one of the following ways:
4105**
4106** <ul>
4107** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
4108** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
4109** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
4110** </ul>
4111**
4112** In other words, you should call sqlite3_column_text(),
4113** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
4114** into the desired format, then invoke sqlite3_column_bytes() or
4115** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
4116** to sqlite3_column_text() or sqlite3_column_blob() with calls to
4117** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
4118** with calls to sqlite3_column_bytes().
4119**
4120** ^The pointers returned are valid until a type conversion occurs as
4121** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
4122** [sqlite3_finalize()] is called. ^The memory space used to hold strings
4123** and BLOBs is freed automatically. Do <em>not</em> pass the pointers returned
4124** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
4125** [sqlite3_free()].
4126**
4127** ^(If a memory allocation error occurs during the evaluation of any
4128** of these routines, a default value is returned. The default value
4129** is either the integer 0, the floating point number 0.0, or a NULL
4130** pointer. Subsequent calls to [sqlite3_errcode()] will return
4131** [SQLITE_NOMEM].)^
4132*/
4133SQLITE_API const void *SQLITE_STDCALL sqlite3_column_blob(sqlite3_stmt*, int iCol);
4134SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes(sqlite3_stmt*, int iCol);
4135SQLITE_API int SQLITE_STDCALL sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
4136SQLITE_API double SQLITE_STDCALL sqlite3_column_double(sqlite3_stmt*, int iCol);
4137SQLITE_API int SQLITE_STDCALL sqlite3_column_int(sqlite3_stmt*, int iCol);
4138SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_column_int64(sqlite3_stmt*, int iCol);
4139SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_column_text(sqlite3_stmt*, int iCol);
4140SQLITE_API const void *SQLITE_STDCALL sqlite3_column_text16(sqlite3_stmt*, int iCol);
4141SQLITE_API int SQLITE_STDCALL sqlite3_column_type(sqlite3_stmt*, int iCol);
4142SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_column_value(sqlite3_stmt*, int iCol);
4143
4144/*
4145** CAPI3REF: Destroy A Prepared Statement Object
4146** DESTRUCTOR: sqlite3_stmt
4147**
4148** ^The sqlite3_finalize() function is called to delete a [prepared statement].
4149** ^If the most recent evaluation of the statement encountered no errors
4150** or if the statement is never been evaluated, then sqlite3_finalize() returns
4151** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
4152** sqlite3_finalize(S) returns the appropriate [error code] or
4153** [extended error code].
4154**
4155** ^The sqlite3_finalize(S) routine can be called at any point during
4156** the life cycle of [prepared statement] S:
4157** before statement S is ever evaluated, after
4158** one or more calls to [sqlite3_reset()], or after any call
4159** to [sqlite3_step()] regardless of whether or not the statement has
4160** completed execution.
4161**
4162** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
4163**
4164** The application must finalize every [prepared statement] in order to avoid
4165** resource leaks. It is a grievous error for the application to try to use
4166** a prepared statement after it has been finalized. Any use of a prepared
4167** statement after it has been finalized can result in undefined and
4168** undesirable behavior such as segfaults and heap corruption.
4169*/
4170SQLITE_API int SQLITE_STDCALL sqlite3_finalize(sqlite3_stmt *pStmt);
4171
4172/*
4173** CAPI3REF: Reset A Prepared Statement Object
4174** METHOD: sqlite3_stmt
4175**
4176** The sqlite3_reset() function is called to reset a [prepared statement]
4177** object back to its initial state, ready to be re-executed.
4178** ^Any SQL statement variables that had values bound to them using
4179** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
4180** Use [sqlite3_clear_bindings()] to reset the bindings.
4181**
4182** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
4183** back to the beginning of its program.
4184**
4185** ^If the most recent call to [sqlite3_step(S)] for the
4186** [prepared statement] S returned [SQLITE_ROW] or [SQLITE_DONE],
4187** or if [sqlite3_step(S)] has never before been called on S,
4188** then [sqlite3_reset(S)] returns [SQLITE_OK].
4189**
4190** ^If the most recent call to [sqlite3_step(S)] for the
4191** [prepared statement] S indicated an error, then
4192** [sqlite3_reset(S)] returns an appropriate [error code].
4193**
4194** ^The [sqlite3_reset(S)] interface does not change the values
4195** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
4196*/
4197SQLITE_API int SQLITE_STDCALL sqlite3_reset(sqlite3_stmt *pStmt);
4198
4199/*
4200** CAPI3REF: Create Or Redefine SQL Functions
4201** KEYWORDS: {function creation routines}
4202** KEYWORDS: {application-defined SQL function}
4203** KEYWORDS: {application-defined SQL functions}
4204** METHOD: sqlite3
4205**
4206** ^These functions (collectively known as "function creation routines")
4207** are used to add SQL functions or aggregates or to redefine the behavior
4208** of existing SQL functions or aggregates. The only differences between
4209** these routines are the text encoding expected for
4210** the second parameter (the name of the function being created)
4211** and the presence or absence of a destructor callback for
4212** the application data pointer.
4213**
4214** ^The first parameter is the [database connection] to which the SQL
4215** function is to be added. ^If an application uses more than one database
4216** connection then application-defined SQL functions must be added
4217** to each database connection separately.
4218**
4219** ^The second parameter is the name of the SQL function to be created or
4220** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
4221** representation, exclusive of the zero-terminator. ^Note that the name
4222** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
4223** ^Any attempt to create a function with a longer name
4224** will result in [SQLITE_MISUSE] being returned.
4225**
4226** ^The third parameter (nArg)
4227** is the number of arguments that the SQL function or
4228** aggregate takes. ^If this parameter is -1, then the SQL function or
4229** aggregate may take any number of arguments between 0 and the limit
4230** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
4231** parameter is less than -1 or greater than 127 then the behavior is
4232** undefined.
4233**
4234** ^The fourth parameter, eTextRep, specifies what
4235** [SQLITE_UTF8 | text encoding] this SQL function prefers for
4236** its parameters. The application should set this parameter to
4237** [SQLITE_UTF16LE] if the function implementation invokes
4238** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
4239** implementation invokes [sqlite3_value_text16be()] on an input, or
4240** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
4241** otherwise. ^The same SQL function may be registered multiple times using
4242** different preferred text encodings, with different implementations for
4243** each encoding.
4244** ^When multiple implementations of the same function are available, SQLite
4245** will pick the one that involves the least amount of data conversion.
4246**
4247** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
4248** to signal that the function will always return the same result given
4249** the same inputs within a single SQL statement. Most SQL functions are
4250** deterministic. The built-in [random()] SQL function is an example of a
4251** function that is not deterministic. The SQLite query planner is able to
4252** perform additional optimizations on deterministic functions, so use
4253** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
4254**
4255** ^(The fifth parameter is an arbitrary pointer. The implementation of the
4256** function can gain access to this pointer using [sqlite3_user_data()].)^
4257**
4258** ^The sixth, seventh and eighth parameters, xFunc, xStep and xFinal, are
4259** pointers to C-language functions that implement the SQL function or
4260** aggregate. ^A scalar SQL function requires an implementation of the xFunc
4261** callback only; NULL pointers must be passed as the xStep and xFinal
4262** parameters. ^An aggregate SQL function requires an implementation of xStep
4263** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
4264** SQL function or aggregate, pass NULL pointers for all three function
4265** callbacks.
4266**
4267** ^(If the ninth parameter to sqlite3_create_function_v2() is not NULL,
4268** then it is destructor for the application data pointer.
4269** The destructor is invoked when the function is deleted, either by being
4270** overloaded or when the database connection closes.)^
4271** ^The destructor is also invoked if the call to
4272** sqlite3_create_function_v2() fails.
4273** ^When the destructor callback of the tenth parameter is invoked, it
4274** is passed a single argument which is a copy of the application data
4275** pointer which was the fifth parameter to sqlite3_create_function_v2().
4276**
4277** ^It is permitted to register multiple implementations of the same
4278** functions with the same name but with either differing numbers of
4279** arguments or differing preferred text encodings. ^SQLite will use
4280** the implementation that most closely matches the way in which the
4281** SQL function is used. ^A function implementation with a non-negative
4282** nArg parameter is a better match than a function implementation with
4283** a negative nArg. ^A function where the preferred text encoding
4284** matches the database encoding is a better
4285** match than a function where the encoding is different.
4286** ^A function where the encoding difference is between UTF16le and UTF16be
4287** is a closer match than a function where the encoding difference is
4288** between UTF8 and UTF16.
4289**
4290** ^Built-in functions may be overloaded by new application-defined functions.
4291**
4292** ^An application-defined function is permitted to call other
4293** SQLite interfaces. However, such calls must not
4294** close the database connection nor finalize or reset the prepared
4295** statement in which the function is running.
4296*/
4297SQLITE_API int SQLITE_STDCALL sqlite3_create_function(
4298 sqlite3 *db,
4299 const char *zFunctionName,
4300 int nArg,
4301 int eTextRep,
4302 void *pApp,
4303 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4304 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4305 void (*xFinal)(sqlite3_context*)
4306);
4307SQLITE_API int SQLITE_STDCALL sqlite3_create_function16(
4308 sqlite3 *db,
4309 const void *zFunctionName,
4310 int nArg,
4311 int eTextRep,
4312 void *pApp,
4313 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4314 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4315 void (*xFinal)(sqlite3_context*)
4316);
4317SQLITE_API int SQLITE_STDCALL sqlite3_create_function_v2(
4318 sqlite3 *db,
4319 const char *zFunctionName,
4320 int nArg,
4321 int eTextRep,
4322 void *pApp,
4323 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
4324 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
4325 void (*xFinal)(sqlite3_context*),
4326 void(*xDestroy)(void*)
4327);
4328
4329/*
4330** CAPI3REF: Text Encodings
4331**
4332** These constant define integer codes that represent the various
4333** text encodings supported by SQLite.
4334*/
4335#define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
4336#define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
4337#define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
4338#define SQLITE_UTF16 4 /* Use native byte order */
4339#define SQLITE_ANY 5 /* Deprecated */
4340#define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
4341
4342/*
4343** CAPI3REF: Function Flags
4344**
4345** These constants may be ORed together with the
4346** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
4347** to [sqlite3_create_function()], [sqlite3_create_function16()], or
4348** [sqlite3_create_function_v2()].
4349*/
4350#define SQLITE_DETERMINISTIC 0x800
4351
4352/*
4353** CAPI3REF: Deprecated Functions
4354** DEPRECATED
4355**
4356** These functions are [deprecated]. In order to maintain
4357** backwards compatibility with older code, these functions continue
4358** to be supported. However, new applications should avoid
4359** the use of these functions. To encourage programmers to avoid
4360** these functions, we will not explain what they do.
4361*/
4362#ifndef SQLITE_OMIT_DEPRECATED
4363SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_aggregate_count(sqlite3_context*);
4364SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_expired(sqlite3_stmt*);
4365SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
4366SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_global_recover(void);
4367SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_thread_cleanup(void);
4368SQLITE_API SQLITE_DEPRECATED int SQLITE_STDCALL sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
4369 void*,sqlite3_int64);
4370#endif
4371
4372/*
4373** CAPI3REF: Obtaining SQL Values
4374** METHOD: sqlite3_value
4375**
4376** The C-language implementation of SQL functions and aggregates uses
4377** this set of interface routines to access the parameter values on
4378** the function or aggregate.
4379**
4380** The xFunc (for scalar functions) or xStep (for aggregates) parameters
4381** to [sqlite3_create_function()] and [sqlite3_create_function16()]
4382** define callbacks that implement the SQL functions and aggregates.
4383** The 3rd parameter to these callbacks is an array of pointers to
4384** [protected sqlite3_value] objects. There is one [sqlite3_value] object for
4385** each parameter to the SQL function. These routines are used to
4386** extract values from the [sqlite3_value] objects.
4387**
4388** These routines work only with [protected sqlite3_value] objects.
4389** Any attempt to use these routines on an [unprotected sqlite3_value]
4390** object results in undefined behavior.
4391**
4392** ^These routines work just like the corresponding [column access functions]
4393** except that these routines take a single [protected sqlite3_value] object
4394** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
4395**
4396** ^The sqlite3_value_text16() interface extracts a UTF-16 string
4397** in the native byte-order of the host machine. ^The
4398** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
4399** extract UTF-16 strings as big-endian and little-endian respectively.
4400**
4401** ^(The sqlite3_value_numeric_type() interface attempts to apply
4402** numeric affinity to the value. This means that an attempt is
4403** made to convert the value to an integer or floating point. If
4404** such a conversion is possible without loss of information (in other
4405** words, if the value is a string that looks like a number)
4406** then the conversion is performed. Otherwise no conversion occurs.
4407** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
4408**
4409** Please pay particular attention to the fact that the pointer returned
4410** from [sqlite3_value_blob()], [sqlite3_value_text()], or
4411** [sqlite3_value_text16()] can be invalidated by a subsequent call to
4412** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
4413** or [sqlite3_value_text16()].
4414**
4415** These routines must be called from the same thread as
4416** the SQL function that supplied the [sqlite3_value*] parameters.
4417*/
4418SQLITE_API const void *SQLITE_STDCALL sqlite3_value_blob(sqlite3_value*);
4419SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes(sqlite3_value*);
4420SQLITE_API int SQLITE_STDCALL sqlite3_value_bytes16(sqlite3_value*);
4421SQLITE_API double SQLITE_STDCALL sqlite3_value_double(sqlite3_value*);
4422SQLITE_API int SQLITE_STDCALL sqlite3_value_int(sqlite3_value*);
4423SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_value_int64(sqlite3_value*);
4424SQLITE_API const unsigned char *SQLITE_STDCALL sqlite3_value_text(sqlite3_value*);
4425SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16(sqlite3_value*);
4426SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16le(sqlite3_value*);
4427SQLITE_API const void *SQLITE_STDCALL sqlite3_value_text16be(sqlite3_value*);
4428SQLITE_API int SQLITE_STDCALL sqlite3_value_type(sqlite3_value*);
4429SQLITE_API int SQLITE_STDCALL sqlite3_value_numeric_type(sqlite3_value*);
4430
4431/*
4432** CAPI3REF: Finding The Subtype Of SQL Values
4433** METHOD: sqlite3_value
4434**
4435** The sqlite3_value_subtype(V) function returns the subtype for
4436** an [application-defined SQL function] argument V. The subtype
4437** information can be used to pass a limited amount of context from
4438** one SQL function to another. Use the [sqlite3_result_subtype()]
4439** routine to set the subtype for the return value of an SQL function.
4440**
4441** SQLite makes no use of subtype itself. It merely passes the subtype
4442** from the result of one [application-defined SQL function] into the
4443** input of another.
4444*/
4445SQLITE_API unsigned int SQLITE_STDCALL sqlite3_value_subtype(sqlite3_value*);
4446
4447/*
4448** CAPI3REF: Copy And Free SQL Values
4449** METHOD: sqlite3_value
4450**
4451** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
4452** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
4453** is a [protected sqlite3_value] object even if the input is not.
4454** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
4455** memory allocation fails.
4456**
4457** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
4458** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
4459** then sqlite3_value_free(V) is a harmless no-op.
4460*/
4461SQLITE_API sqlite3_value *SQLITE_STDCALL sqlite3_value_dup(const sqlite3_value*);
4462SQLITE_API void SQLITE_STDCALL sqlite3_value_free(sqlite3_value*);
4463
4464/*
4465** CAPI3REF: Obtain Aggregate Function Context
4466** METHOD: sqlite3_context
4467**
4468** Implementations of aggregate SQL functions use this
4469** routine to allocate memory for storing their state.
4470**
4471** ^The first time the sqlite3_aggregate_context(C,N) routine is called
4472** for a particular aggregate function, SQLite
4473** allocates N of memory, zeroes out that memory, and returns a pointer
4474** to the new memory. ^On second and subsequent calls to
4475** sqlite3_aggregate_context() for the same aggregate function instance,
4476** the same buffer is returned. Sqlite3_aggregate_context() is normally
4477** called once for each invocation of the xStep callback and then one
4478** last time when the xFinal callback is invoked. ^(When no rows match
4479** an aggregate query, the xStep() callback of the aggregate function
4480** implementation is never called and xFinal() is called exactly once.
4481** In those cases, sqlite3_aggregate_context() might be called for the
4482** first time from within xFinal().)^
4483**
4484** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
4485** when first called if N is less than or equal to zero or if a memory
4486** allocate error occurs.
4487**
4488** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
4489** determined by the N parameter on first successful call. Changing the
4490** value of N in subsequent call to sqlite3_aggregate_context() within
4491** the same aggregate function instance will not resize the memory
4492** allocation.)^ Within the xFinal callback, it is customary to set
4493** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
4494** pointless memory allocations occur.
4495**
4496** ^SQLite automatically frees the memory allocated by
4497** sqlite3_aggregate_context() when the aggregate query concludes.
4498**
4499** The first parameter must be a copy of the
4500** [sqlite3_context | SQL function context] that is the first parameter
4501** to the xStep or xFinal callback routine that implements the aggregate
4502** function.
4503**
4504** This routine must be called from the same thread in which
4505** the aggregate SQL function is running.
4506*/
4507SQLITE_API void *SQLITE_STDCALL sqlite3_aggregate_context(sqlite3_context*, int nBytes);
4508
4509/*
4510** CAPI3REF: User Data For Functions
4511** METHOD: sqlite3_context
4512**
4513** ^The sqlite3_user_data() interface returns a copy of
4514** the pointer that was the pUserData parameter (the 5th parameter)
4515** of the [sqlite3_create_function()]
4516** and [sqlite3_create_function16()] routines that originally
4517** registered the application defined function.
4518**
4519** This routine must be called from the same thread in which
4520** the application-defined function is running.
4521*/
4522SQLITE_API void *SQLITE_STDCALL sqlite3_user_data(sqlite3_context*);
4523
4524/*
4525** CAPI3REF: Database Connection For Functions
4526** METHOD: sqlite3_context
4527**
4528** ^The sqlite3_context_db_handle() interface returns a copy of
4529** the pointer to the [database connection] (the 1st parameter)
4530** of the [sqlite3_create_function()]
4531** and [sqlite3_create_function16()] routines that originally
4532** registered the application defined function.
4533*/
4534SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_context_db_handle(sqlite3_context*);
4535
4536/*
4537** CAPI3REF: Function Auxiliary Data
4538** METHOD: sqlite3_context
4539**
4540** These functions may be used by (non-aggregate) SQL functions to
4541** associate metadata with argument values. If the same value is passed to
4542** multiple invocations of the same SQL function during query execution, under
4543** some circumstances the associated metadata may be preserved. An example
4544** of where this might be useful is in a regular-expression matching
4545** function. The compiled version of the regular expression can be stored as
4546** metadata associated with the pattern string.
4547** Then as long as the pattern string remains the same,
4548** the compiled regular expression can be reused on multiple
4549** invocations of the same function.
4550**
4551** ^The sqlite3_get_auxdata() interface returns a pointer to the metadata
4552** associated by the sqlite3_set_auxdata() function with the Nth argument
4553** value to the application-defined function. ^If there is no metadata
4554** associated with the function argument, this sqlite3_get_auxdata() interface
4555** returns a NULL pointer.
4556**
4557** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as metadata for the N-th
4558** argument of the application-defined function. ^Subsequent
4559** calls to sqlite3_get_auxdata(C,N) return P from the most recent
4560** sqlite3_set_auxdata(C,N,P,X) call if the metadata is still valid or
4561** NULL if the metadata has been discarded.
4562** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
4563** SQLite will invoke the destructor function X with parameter P exactly
4564** once, when the metadata is discarded.
4565** SQLite is free to discard the metadata at any time, including: <ul>
4566** <li> when the corresponding function parameter changes, or
4567** <li> when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
4568** SQL statement, or
4569** <li> when sqlite3_set_auxdata() is invoked again on the same parameter, or
4570** <li> during the original sqlite3_set_auxdata() call when a memory
4571** allocation error occurs. </ul>)^
4572**
4573** Note the last bullet in particular. The destructor X in
4574** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
4575** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
4576** should be called near the end of the function implementation and the
4577** function implementation should not make any use of P after
4578** sqlite3_set_auxdata() has been called.
4579**
4580** ^(In practice, metadata is preserved between function calls for
4581** function parameters that are compile-time constants, including literal
4582** values and [parameters] and expressions composed from the same.)^
4583**
4584** These routines must be called from the same thread in which
4585** the SQL function is running.
4586*/
4587SQLITE_API void *SQLITE_STDCALL sqlite3_get_auxdata(sqlite3_context*, int N);
4588SQLITE_API void SQLITE_STDCALL sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
4589
4590
4591/*
4592** CAPI3REF: Constants Defining Special Destructor Behavior
4593**
4594** These are special values for the destructor that is passed in as the
4595** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
4596** argument is SQLITE_STATIC, it means that the content pointer is constant
4597** and will never change. It does not need to be destroyed. ^The
4598** SQLITE_TRANSIENT value means that the content will likely change in
4599** the near future and that SQLite should make its own private copy of
4600** the content before returning.
4601**
4602** The typedef is necessary to work around problems in certain
4603** C++ compilers.
4604*/
4605typedef void (*sqlite3_destructor_type)(void*);
4606#define SQLITE_STATIC ((sqlite3_destructor_type)0)
4607#define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
4608
4609/*
4610** CAPI3REF: Setting The Result Of An SQL Function
4611** METHOD: sqlite3_context
4612**
4613** These routines are used by the xFunc or xFinal callbacks that
4614** implement SQL functions and aggregates. See
4615** [sqlite3_create_function()] and [sqlite3_create_function16()]
4616** for additional information.
4617**
4618** These functions work very much like the [parameter binding] family of
4619** functions used to bind values to host parameters in prepared statements.
4620** Refer to the [SQL parameter] documentation for additional information.
4621**
4622** ^The sqlite3_result_blob() interface sets the result from
4623** an application-defined function to be the BLOB whose content is pointed
4624** to by the second parameter and which is N bytes long where N is the
4625** third parameter.
4626**
4627** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
4628** interfaces set the result of the application-defined function to be
4629** a BLOB containing all zero bytes and N bytes in size.
4630**
4631** ^The sqlite3_result_double() interface sets the result from
4632** an application-defined function to be a floating point value specified
4633** by its 2nd argument.
4634**
4635** ^The sqlite3_result_error() and sqlite3_result_error16() functions
4636** cause the implemented SQL function to throw an exception.
4637** ^SQLite uses the string pointed to by the
4638** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
4639** as the text of an error message. ^SQLite interprets the error
4640** message string from sqlite3_result_error() as UTF-8. ^SQLite
4641** interprets the string from sqlite3_result_error16() as UTF-16 in native
4642** byte order. ^If the third parameter to sqlite3_result_error()
4643** or sqlite3_result_error16() is negative then SQLite takes as the error
4644** message all text up through the first zero character.
4645** ^If the third parameter to sqlite3_result_error() or
4646** sqlite3_result_error16() is non-negative then SQLite takes that many
4647** bytes (not characters) from the 2nd parameter as the error message.
4648** ^The sqlite3_result_error() and sqlite3_result_error16()
4649** routines make a private copy of the error message text before
4650** they return. Hence, the calling function can deallocate or
4651** modify the text after they return without harm.
4652** ^The sqlite3_result_error_code() function changes the error code
4653** returned by SQLite as a result of an error in a function. ^By default,
4654** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
4655** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
4656**
4657** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
4658** error indicating that a string or BLOB is too long to represent.
4659**
4660** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
4661** error indicating that a memory allocation failed.
4662**
4663** ^The sqlite3_result_int() interface sets the return value
4664** of the application-defined function to be the 32-bit signed integer
4665** value given in the 2nd argument.
4666** ^The sqlite3_result_int64() interface sets the return value
4667** of the application-defined function to be the 64-bit signed integer
4668** value given in the 2nd argument.
4669**
4670** ^The sqlite3_result_null() interface sets the return value
4671** of the application-defined function to be NULL.
4672**
4673** ^The sqlite3_result_text(), sqlite3_result_text16(),
4674** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
4675** set the return value of the application-defined function to be
4676** a text string which is represented as UTF-8, UTF-16 native byte order,
4677** UTF-16 little endian, or UTF-16 big endian, respectively.
4678** ^The sqlite3_result_text64() interface sets the return value of an
4679** application-defined function to be a text string in an encoding
4680** specified by the fifth (and last) parameter, which must be one
4681** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
4682** ^SQLite takes the text result from the application from
4683** the 2nd parameter of the sqlite3_result_text* interfaces.
4684** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4685** is negative, then SQLite takes result text from the 2nd parameter
4686** through the first zero character.
4687** ^If the 3rd parameter to the sqlite3_result_text* interfaces
4688** is non-negative, then as many bytes (not characters) of the text
4689** pointed to by the 2nd parameter are taken as the application-defined
4690** function result. If the 3rd parameter is non-negative, then it
4691** must be the byte offset into the string where the NUL terminator would
4692** appear if the string where NUL terminated. If any NUL characters occur
4693** in the string at a byte offset that is less than the value of the 3rd
4694** parameter, then the resulting string will contain embedded NULs and the
4695** result of expressions operating on strings with embedded NULs is undefined.
4696** ^If the 4th parameter to the sqlite3_result_text* interfaces
4697** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
4698** function as the destructor on the text or BLOB result when it has
4699** finished using that result.
4700** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
4701** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
4702** assumes that the text or BLOB result is in constant space and does not
4703** copy the content of the parameter nor call a destructor on the content
4704** when it has finished using that result.
4705** ^If the 4th parameter to the sqlite3_result_text* interfaces
4706** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
4707** then SQLite makes a copy of the result into space obtained from
4708** from [sqlite3_malloc()] before it returns.
4709**
4710** ^The sqlite3_result_value() interface sets the result of
4711** the application-defined function to be a copy of the
4712** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
4713** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
4714** so that the [sqlite3_value] specified in the parameter may change or
4715** be deallocated after sqlite3_result_value() returns without harm.
4716** ^A [protected sqlite3_value] object may always be used where an
4717** [unprotected sqlite3_value] object is required, so either
4718** kind of [sqlite3_value] object can be used with this interface.
4719**
4720** If these routines are called from within the different thread
4721** than the one containing the application-defined function that received
4722** the [sqlite3_context] pointer, the results are undefined.
4723*/
4724SQLITE_API void SQLITE_STDCALL sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
4725SQLITE_API void SQLITE_STDCALL sqlite3_result_blob64(sqlite3_context*,const void*,
4726 sqlite3_uint64,void(*)(void*));
4727SQLITE_API void SQLITE_STDCALL sqlite3_result_double(sqlite3_context*, double);
4728SQLITE_API void SQLITE_STDCALL sqlite3_result_error(sqlite3_context*, const char*, int);
4729SQLITE_API void SQLITE_STDCALL sqlite3_result_error16(sqlite3_context*, const void*, int);
4730SQLITE_API void SQLITE_STDCALL sqlite3_result_error_toobig(sqlite3_context*);
4731SQLITE_API void SQLITE_STDCALL sqlite3_result_error_nomem(sqlite3_context*);
4732SQLITE_API void SQLITE_STDCALL sqlite3_result_error_code(sqlite3_context*, int);
4733SQLITE_API void SQLITE_STDCALL sqlite3_result_int(sqlite3_context*, int);
4734SQLITE_API void SQLITE_STDCALL sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
4735SQLITE_API void SQLITE_STDCALL sqlite3_result_null(sqlite3_context*);
4736SQLITE_API void SQLITE_STDCALL sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
4737SQLITE_API void SQLITE_STDCALL sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
4738 void(*)(void*), unsigned char encoding);
4739SQLITE_API void SQLITE_STDCALL sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
4740SQLITE_API void SQLITE_STDCALL sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
4741SQLITE_API void SQLITE_STDCALL sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
4742SQLITE_API void SQLITE_STDCALL sqlite3_result_value(sqlite3_context*, sqlite3_value*);
4743SQLITE_API void SQLITE_STDCALL sqlite3_result_zeroblob(sqlite3_context*, int n);
4744SQLITE_API int SQLITE_STDCALL sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
4745
4746
4747/*
4748** CAPI3REF: Setting The Subtype Of An SQL Function
4749** METHOD: sqlite3_context
4750**
4751** The sqlite3_result_subtype(C,T) function causes the subtype of
4752** the result from the [application-defined SQL function] with
4753** [sqlite3_context] C to be the value T. Only the lower 8 bits
4754** of the subtype T are preserved in current versions of SQLite;
4755** higher order bits are discarded.
4756** The number of subtype bytes preserved by SQLite might increase
4757** in future releases of SQLite.
4758*/
4759SQLITE_API void SQLITE_STDCALL sqlite3_result_subtype(sqlite3_context*,unsigned int);
4760
4761/*
4762** CAPI3REF: Define New Collating Sequences
4763** METHOD: sqlite3
4764**
4765** ^These functions add, remove, or modify a [collation] associated
4766** with the [database connection] specified as the first argument.
4767**
4768** ^The name of the collation is a UTF-8 string
4769** for sqlite3_create_collation() and sqlite3_create_collation_v2()
4770** and a UTF-16 string in native byte order for sqlite3_create_collation16().
4771** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
4772** considered to be the same name.
4773**
4774** ^(The third argument (eTextRep) must be one of the constants:
4775** <ul>
4776** <li> [SQLITE_UTF8],
4777** <li> [SQLITE_UTF16LE],
4778** <li> [SQLITE_UTF16BE],
4779** <li> [SQLITE_UTF16], or
4780** <li> [SQLITE_UTF16_ALIGNED].
4781** </ul>)^
4782** ^The eTextRep argument determines the encoding of strings passed
4783** to the collating function callback, xCallback.
4784** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
4785** force strings to be UTF16 with native byte order.
4786** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
4787** on an even byte address.
4788**
4789** ^The fourth argument, pArg, is an application data pointer that is passed
4790** through as the first argument to the collating function callback.
4791**
4792** ^The fifth argument, xCallback, is a pointer to the collating function.
4793** ^Multiple collating functions can be registered using the same name but
4794** with different eTextRep parameters and SQLite will use whichever
4795** function requires the least amount of data transformation.
4796** ^If the xCallback argument is NULL then the collating function is
4797** deleted. ^When all collating functions having the same name are deleted,
4798** that collation is no longer usable.
4799**
4800** ^The collating function callback is invoked with a copy of the pArg
4801** application data pointer and with two strings in the encoding specified
4802** by the eTextRep argument. The collating function must return an
4803** integer that is negative, zero, or positive
4804** if the first string is less than, equal to, or greater than the second,
4805** respectively. A collating function must always return the same answer
4806** given the same inputs. If two or more collating functions are registered
4807** to the same collation name (using different eTextRep values) then all
4808** must give an equivalent answer when invoked with equivalent strings.
4809** The collating function must obey the following properties for all
4810** strings A, B, and C:
4811**
4812** <ol>
4813** <li> If A==B then B==A.
4814** <li> If A==B and B==C then A==C.
4815** <li> If A<B THEN B>A.
4816** <li> If A<B and B<C then A<C.
4817** </ol>
4818**
4819** If a collating function fails any of the above constraints and that
4820** collating function is registered and used, then the behavior of SQLite
4821** is undefined.
4822**
4823** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
4824** with the addition that the xDestroy callback is invoked on pArg when
4825** the collating function is deleted.
4826** ^Collating functions are deleted when they are overridden by later
4827** calls to the collation creation functions or when the
4828** [database connection] is closed using [sqlite3_close()].
4829**
4830** ^The xDestroy callback is <u>not</u> called if the
4831** sqlite3_create_collation_v2() function fails. Applications that invoke
4832** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
4833** check the return code and dispose of the application data pointer
4834** themselves rather than expecting SQLite to deal with it for them.
4835** This is different from every other SQLite interface. The inconsistency
4836** is unfortunate but cannot be changed without breaking backwards
4837** compatibility.
4838**
4839** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
4840*/
4841SQLITE_API int SQLITE_STDCALL sqlite3_create_collation(
4842 sqlite3*,
4843 const char *zName,
4844 int eTextRep,
4845 void *pArg,
4846 int(*xCompare)(void*,int,const void*,int,const void*)
4847);
4848SQLITE_API int SQLITE_STDCALL sqlite3_create_collation_v2(
4849 sqlite3*,
4850 const char *zName,
4851 int eTextRep,
4852 void *pArg,
4853 int(*xCompare)(void*,int,const void*,int,const void*),
4854 void(*xDestroy)(void*)
4855);
4856SQLITE_API int SQLITE_STDCALL sqlite3_create_collation16(
4857 sqlite3*,
4858 const void *zName,
4859 int eTextRep,
4860 void *pArg,
4861 int(*xCompare)(void*,int,const void*,int,const void*)
4862);
4863
4864/*
4865** CAPI3REF: Collation Needed Callbacks
4866** METHOD: sqlite3
4867**
4868** ^To avoid having to register all collation sequences before a database
4869** can be used, a single callback function may be registered with the
4870** [database connection] to be invoked whenever an undefined collation
4871** sequence is required.
4872**
4873** ^If the function is registered using the sqlite3_collation_needed() API,
4874** then it is passed the names of undefined collation sequences as strings
4875** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
4876** the names are passed as UTF-16 in machine native byte order.
4877** ^A call to either function replaces the existing collation-needed callback.
4878**
4879** ^(When the callback is invoked, the first argument passed is a copy
4880** of the second argument to sqlite3_collation_needed() or
4881** sqlite3_collation_needed16(). The second argument is the database
4882** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
4883** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
4884** sequence function required. The fourth parameter is the name of the
4885** required collation sequence.)^
4886**
4887** The callback function should register the desired collation using
4888** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
4889** [sqlite3_create_collation_v2()].
4890*/
4891SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed(
4892 sqlite3*,
4893 void*,
4894 void(*)(void*,sqlite3*,int eTextRep,const char*)
4895);
4896SQLITE_API int SQLITE_STDCALL sqlite3_collation_needed16(
4897 sqlite3*,
4898 void*,
4899 void(*)(void*,sqlite3*,int eTextRep,const void*)
4900);
4901
4902#ifdef SQLITE_HAS_CODEC
4903/*
4904** Specify the key for an encrypted database. This routine should be
4905** called right after sqlite3_open().
4906**
4907** The code to implement this API is not available in the public release
4908** of SQLite.
4909*/
4910SQLITE_API int SQLITE_STDCALL sqlite3_key(
4911 sqlite3 *db, /* Database to be rekeyed */
4912 const void *pKey, int nKey /* The key */
4913);
4914SQLITE_API int SQLITE_STDCALL sqlite3_key_v2(
4915 sqlite3 *db, /* Database to be rekeyed */
4916 const char *zDbName, /* Name of the database */
4917 const void *pKey, int nKey /* The key */
4918);
4919
4920/*
4921** Change the key on an open database. If the current database is not
4922** encrypted, this routine will encrypt it. If pNew==0 or nNew==0, the
4923** database is decrypted.
4924**
4925** The code to implement this API is not available in the public release
4926** of SQLite.
4927*/
4928SQLITE_API int SQLITE_STDCALL sqlite3_rekey(
4929 sqlite3 *db, /* Database to be rekeyed */
4930 const void *pKey, int nKey /* The new key */
4931);
4932SQLITE_API int SQLITE_STDCALL sqlite3_rekey_v2(
4933 sqlite3 *db, /* Database to be rekeyed */
4934 const char *zDbName, /* Name of the database */
4935 const void *pKey, int nKey /* The new key */
4936);
4937
4938/*
4939** Specify the activation key for a SEE database. Unless
4940** activated, none of the SEE routines will work.
4941*/
4942SQLITE_API void SQLITE_STDCALL sqlite3_activate_see(
4943 const char *zPassPhrase /* Activation phrase */
4944);
4945#endif
4946
4947#ifdef SQLITE_ENABLE_CEROD
4948/*
4949** Specify the activation key for a CEROD database. Unless
4950** activated, none of the CEROD routines will work.
4951*/
4952SQLITE_API void SQLITE_STDCALL sqlite3_activate_cerod(
4953 const char *zPassPhrase /* Activation phrase */
4954);
4955#endif
4956
4957/*
4958** CAPI3REF: Suspend Execution For A Short Time
4959**
4960** The sqlite3_sleep() function causes the current thread to suspend execution
4961** for at least a number of milliseconds specified in its parameter.
4962**
4963** If the operating system does not support sleep requests with
4964** millisecond time resolution, then the time will be rounded up to
4965** the nearest second. The number of milliseconds of sleep actually
4966** requested from the operating system is returned.
4967**
4968** ^SQLite implements this interface by calling the xSleep()
4969** method of the default [sqlite3_vfs] object. If the xSleep() method
4970** of the default VFS is not implemented correctly, or not implemented at
4971** all, then the behavior of sqlite3_sleep() may deviate from the description
4972** in the previous paragraphs.
4973*/
4974SQLITE_API int SQLITE_STDCALL sqlite3_sleep(int);
4975
4976/*
4977** CAPI3REF: Name Of The Folder Holding Temporary Files
4978**
4979** ^(If this global variable is made to point to a string which is
4980** the name of a folder (a.k.a. directory), then all temporary files
4981** created by SQLite when using a built-in [sqlite3_vfs | VFS]
4982** will be placed in that directory.)^ ^If this variable
4983** is a NULL pointer, then SQLite performs a search for an appropriate
4984** temporary file directory.
4985**
4986** Applications are strongly discouraged from using this global variable.
4987** It is required to set a temporary folder on Windows Runtime (WinRT).
4988** But for all other platforms, it is highly recommended that applications
4989** neither read nor write this variable. This global variable is a relic
4990** that exists for backwards compatibility of legacy applications and should
4991** be avoided in new projects.
4992**
4993** It is not safe to read or modify this variable in more than one
4994** thread at a time. It is not safe to read or modify this variable
4995** if a [database connection] is being used at the same time in a separate
4996** thread.
4997** It is intended that this variable be set once
4998** as part of process initialization and before any SQLite interface
4999** routines have been called and that this variable remain unchanged
5000** thereafter.
5001**
5002** ^The [temp_store_directory pragma] may modify this variable and cause
5003** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5004** the [temp_store_directory pragma] always assumes that any string
5005** that this variable points to is held in memory obtained from
5006** [sqlite3_malloc] and the pragma may attempt to free that memory
5007** using [sqlite3_free].
5008** Hence, if this variable is modified directly, either it should be
5009** made NULL or made to point to memory obtained from [sqlite3_malloc]
5010** or else the use of the [temp_store_directory pragma] should be avoided.
5011** Except when requested by the [temp_store_directory pragma], SQLite
5012** does not free the memory that sqlite3_temp_directory points to. If
5013** the application wants that memory to be freed, it must do
5014** so itself, taking care to only do so after all [database connection]
5015** objects have been destroyed.
5016**
5017** <b>Note to Windows Runtime users:</b> The temporary directory must be set
5018** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
5019** features that require the use of temporary files may fail. Here is an
5020** example of how to do this using C++ with the Windows Runtime:
5021**
5022** <blockquote><pre>
5023** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
5024** TemporaryFolder->Path->Data();
5025** char zPathBuf[MAX_PATH + 1];
5026** memset(zPathBuf, 0, sizeof(zPathBuf));
5027** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
5028** NULL, NULL);
5029** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
5030** </pre></blockquote>
5031*/
5032SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
5033
5034/*
5035** CAPI3REF: Name Of The Folder Holding Database Files
5036**
5037** ^(If this global variable is made to point to a string which is
5038** the name of a folder (a.k.a. directory), then all database files
5039** specified with a relative pathname and created or accessed by
5040** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
5041** to be relative to that directory.)^ ^If this variable is a NULL
5042** pointer, then SQLite assumes that all database files specified
5043** with a relative pathname are relative to the current directory
5044** for the process. Only the windows VFS makes use of this global
5045** variable; it is ignored by the unix VFS.
5046**
5047** Changing the value of this variable while a database connection is
5048** open can result in a corrupt database.
5049**
5050** It is not safe to read or modify this variable in more than one
5051** thread at a time. It is not safe to read or modify this variable
5052** if a [database connection] is being used at the same time in a separate
5053** thread.
5054** It is intended that this variable be set once
5055** as part of process initialization and before any SQLite interface
5056** routines have been called and that this variable remain unchanged
5057** thereafter.
5058**
5059** ^The [data_store_directory pragma] may modify this variable and cause
5060** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
5061** the [data_store_directory pragma] always assumes that any string
5062** that this variable points to is held in memory obtained from
5063** [sqlite3_malloc] and the pragma may attempt to free that memory
5064** using [sqlite3_free].
5065** Hence, if this variable is modified directly, either it should be
5066** made NULL or made to point to memory obtained from [sqlite3_malloc]
5067** or else the use of the [data_store_directory pragma] should be avoided.
5068*/
5069SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
5070
5071/*
5072** CAPI3REF: Test For Auto-Commit Mode
5073** KEYWORDS: {autocommit mode}
5074** METHOD: sqlite3
5075**
5076** ^The sqlite3_get_autocommit() interface returns non-zero or
5077** zero if the given database connection is or is not in autocommit mode,
5078** respectively. ^Autocommit mode is on by default.
5079** ^Autocommit mode is disabled by a [BEGIN] statement.
5080** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
5081**
5082** If certain kinds of errors occur on a statement within a multi-statement
5083** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
5084** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
5085** transaction might be rolled back automatically. The only way to
5086** find out whether SQLite automatically rolled back the transaction after
5087** an error is to use this function.
5088**
5089** If another thread changes the autocommit status of the database
5090** connection while this routine is running, then the return value
5091** is undefined.
5092*/
5093SQLITE_API int SQLITE_STDCALL sqlite3_get_autocommit(sqlite3*);
5094
5095/*
5096** CAPI3REF: Find The Database Handle Of A Prepared Statement
5097** METHOD: sqlite3_stmt
5098**
5099** ^The sqlite3_db_handle interface returns the [database connection] handle
5100** to which a [prepared statement] belongs. ^The [database connection]
5101** returned by sqlite3_db_handle is the same [database connection]
5102** that was the first argument
5103** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
5104** create the statement in the first place.
5105*/
5106SQLITE_API sqlite3 *SQLITE_STDCALL sqlite3_db_handle(sqlite3_stmt*);
5107
5108/*
5109** CAPI3REF: Return The Filename For A Database Connection
5110** METHOD: sqlite3
5111**
5112** ^The sqlite3_db_filename(D,N) interface returns a pointer to a filename
5113** associated with database N of connection D. ^The main database file
5114** has the name "main". If there is no attached database N on the database
5115** connection D, or if database N is a temporary or in-memory database, then
5116** a NULL pointer is returned.
5117**
5118** ^The filename returned by this function is the output of the
5119** xFullPathname method of the [VFS]. ^In other words, the filename
5120** will be an absolute pathname, even if the filename used
5121** to open the database originally was a URI or relative pathname.
5122*/
5123SQLITE_API const char *SQLITE_STDCALL sqlite3_db_filename(sqlite3 *db, const char *zDbName);
5124
5125/*
5126** CAPI3REF: Determine if a database is read-only
5127** METHOD: sqlite3
5128**
5129** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
5130** of connection D is read-only, 0 if it is read/write, or -1 if N is not
5131** the name of a database on connection D.
5132*/
5133SQLITE_API int SQLITE_STDCALL sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
5134
5135/*
5136** CAPI3REF: Find the next prepared statement
5137** METHOD: sqlite3
5138**
5139** ^This interface returns a pointer to the next [prepared statement] after
5140** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
5141** then this interface returns a pointer to the first prepared statement
5142** associated with the database connection pDb. ^If no prepared statement
5143** satisfies the conditions of this routine, it returns NULL.
5144**
5145** The [database connection] pointer D in a call to
5146** [sqlite3_next_stmt(D,S)] must refer to an open database
5147** connection and in particular must not be a NULL pointer.
5148*/
5149SQLITE_API sqlite3_stmt *SQLITE_STDCALL sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
5150
5151/*
5152** CAPI3REF: Commit And Rollback Notification Callbacks
5153** METHOD: sqlite3
5154**
5155** ^The sqlite3_commit_hook() interface registers a callback
5156** function to be invoked whenever a transaction is [COMMIT | committed].
5157** ^Any callback set by a previous call to sqlite3_commit_hook()
5158** for the same database connection is overridden.
5159** ^The sqlite3_rollback_hook() interface registers a callback
5160** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
5161** ^Any callback set by a previous call to sqlite3_rollback_hook()
5162** for the same database connection is overridden.
5163** ^The pArg argument is passed through to the callback.
5164** ^If the callback on a commit hook function returns non-zero,
5165** then the commit is converted into a rollback.
5166**
5167** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
5168** return the P argument from the previous call of the same function
5169** on the same [database connection] D, or NULL for
5170** the first call for each function on D.
5171**
5172** The commit and rollback hook callbacks are not reentrant.
5173** The callback implementation must not do anything that will modify
5174** the database connection that invoked the callback. Any actions
5175** to modify the database connection must be deferred until after the
5176** completion of the [sqlite3_step()] call that triggered the commit
5177** or rollback hook in the first place.
5178** Note that running any other SQL statements, including SELECT statements,
5179** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
5180** the database connections for the meaning of "modify" in this paragraph.
5181**
5182** ^Registering a NULL function disables the callback.
5183**
5184** ^When the commit hook callback routine returns zero, the [COMMIT]
5185** operation is allowed to continue normally. ^If the commit hook
5186** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
5187** ^The rollback hook is invoked on a rollback that results from a commit
5188** hook returning non-zero, just as it would be with any other rollback.
5189**
5190** ^For the purposes of this API, a transaction is said to have been
5191** rolled back if an explicit "ROLLBACK" statement is executed, or
5192** an error or constraint causes an implicit rollback to occur.
5193** ^The rollback callback is not invoked if a transaction is
5194** automatically rolled back because the database connection is closed.
5195**
5196** See also the [sqlite3_update_hook()] interface.
5197*/
5198SQLITE_API void *SQLITE_STDCALL sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
5199SQLITE_API void *SQLITE_STDCALL sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
5200
5201/*
5202** CAPI3REF: Data Change Notification Callbacks
5203** METHOD: sqlite3
5204**
5205** ^The sqlite3_update_hook() interface registers a callback function
5206** with the [database connection] identified by the first argument
5207** to be invoked whenever a row is updated, inserted or deleted in
5208** a [rowid table].
5209** ^Any callback set by a previous call to this function
5210** for the same database connection is overridden.
5211**
5212** ^The second argument is a pointer to the function to invoke when a
5213** row is updated, inserted or deleted in a rowid table.
5214** ^The first argument to the callback is a copy of the third argument
5215** to sqlite3_update_hook().
5216** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
5217** or [SQLITE_UPDATE], depending on the operation that caused the callback
5218** to be invoked.
5219** ^The third and fourth arguments to the callback contain pointers to the
5220** database and table name containing the affected row.
5221** ^The final callback parameter is the [rowid] of the row.
5222** ^In the case of an update, this is the [rowid] after the update takes place.
5223**
5224** ^(The update hook is not invoked when internal system tables are
5225** modified (i.e. sqlite_master and sqlite_sequence).)^
5226** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
5227**
5228** ^In the current implementation, the update hook
5229** is not invoked when duplication rows are deleted because of an
5230** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
5231** invoked when rows are deleted using the [truncate optimization].
5232** The exceptions defined in this paragraph might change in a future
5233** release of SQLite.
5234**
5235** The update hook implementation must not do anything that will modify
5236** the database connection that invoked the update hook. Any actions
5237** to modify the database connection must be deferred until after the
5238** completion of the [sqlite3_step()] call that triggered the update hook.
5239** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
5240** database connections for the meaning of "modify" in this paragraph.
5241**
5242** ^The sqlite3_update_hook(D,C,P) function
5243** returns the P argument from the previous call
5244** on the same [database connection] D, or NULL for
5245** the first call on D.
5246**
5247** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
5248** and [sqlite3_preupdate_hook()] interfaces.
5249*/
5250SQLITE_API void *SQLITE_STDCALL sqlite3_update_hook(
5251 sqlite3*,
5252 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
5253 void*
5254);
5255
5256/*
5257** CAPI3REF: Enable Or Disable Shared Pager Cache
5258**
5259** ^(This routine enables or disables the sharing of the database cache
5260** and schema data structures between [database connection | connections]
5261** to the same database. Sharing is enabled if the argument is true
5262** and disabled if the argument is false.)^
5263**
5264** ^Cache sharing is enabled and disabled for an entire process.
5265** This is a change as of SQLite version 3.5.0. In prior versions of SQLite,
5266** sharing was enabled or disabled for each thread separately.
5267**
5268** ^(The cache sharing mode set by this interface effects all subsequent
5269** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
5270** Existing database connections continue use the sharing mode
5271** that was in effect at the time they were opened.)^
5272**
5273** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
5274** successfully. An [error code] is returned otherwise.)^
5275**
5276** ^Shared cache is disabled by default. But this might change in
5277** future releases of SQLite. Applications that care about shared
5278** cache setting should set it explicitly.
5279**
5280** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
5281** and will always return SQLITE_MISUSE. On those systems,
5282** shared cache mode should be enabled per-database connection via
5283** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
5284**
5285** This interface is threadsafe on processors where writing a
5286** 32-bit integer is atomic.
5287**
5288** See Also: [SQLite Shared-Cache Mode]
5289*/
5290SQLITE_API int SQLITE_STDCALL sqlite3_enable_shared_cache(int);
5291
5292/*
5293** CAPI3REF: Attempt To Free Heap Memory
5294**
5295** ^The sqlite3_release_memory() interface attempts to free N bytes
5296** of heap memory by deallocating non-essential memory allocations
5297** held by the database library. Memory used to cache database
5298** pages to improve performance is an example of non-essential memory.
5299** ^sqlite3_release_memory() returns the number of bytes actually freed,
5300** which might be more or less than the amount requested.
5301** ^The sqlite3_release_memory() routine is a no-op returning zero
5302** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5303**
5304** See also: [sqlite3_db_release_memory()]
5305*/
5306SQLITE_API int SQLITE_STDCALL sqlite3_release_memory(int);
5307
5308/*
5309** CAPI3REF: Free Memory Used By A Database Connection
5310** METHOD: sqlite3
5311**
5312** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
5313** memory as possible from database connection D. Unlike the
5314** [sqlite3_release_memory()] interface, this interface is in effect even
5315** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
5316** omitted.
5317**
5318** See also: [sqlite3_release_memory()]
5319*/
5320SQLITE_API int SQLITE_STDCALL sqlite3_db_release_memory(sqlite3*);
5321
5322/*
5323** CAPI3REF: Impose A Limit On Heap Size
5324**
5325** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
5326** soft limit on the amount of heap memory that may be allocated by SQLite.
5327** ^SQLite strives to keep heap memory utilization below the soft heap
5328** limit by reducing the number of pages held in the page cache
5329** as heap memory usages approaches the limit.
5330** ^The soft heap limit is "soft" because even though SQLite strives to stay
5331** below the limit, it will exceed the limit rather than generate
5332** an [SQLITE_NOMEM] error. In other words, the soft heap limit
5333** is advisory only.
5334**
5335** ^The return value from sqlite3_soft_heap_limit64() is the size of
5336** the soft heap limit prior to the call, or negative in the case of an
5337** error. ^If the argument N is negative
5338** then no change is made to the soft heap limit. Hence, the current
5339** size of the soft heap limit can be determined by invoking
5340** sqlite3_soft_heap_limit64() with a negative argument.
5341**
5342** ^If the argument N is zero then the soft heap limit is disabled.
5343**
5344** ^(The soft heap limit is not enforced in the current implementation
5345** if one or more of following conditions are true:
5346**
5347** <ul>
5348** <li> The soft heap limit is set to zero.
5349** <li> Memory accounting is disabled using a combination of the
5350** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
5351** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
5352** <li> An alternative page cache implementation is specified using
5353** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
5354** <li> The page cache allocates from its own memory pool supplied
5355** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
5356** from the heap.
5357** </ul>)^
5358**
5359** Beginning with SQLite version 3.7.3, the soft heap limit is enforced
5360** regardless of whether or not the [SQLITE_ENABLE_MEMORY_MANAGEMENT]
5361** compile-time option is invoked. With [SQLITE_ENABLE_MEMORY_MANAGEMENT],
5362** the soft heap limit is enforced on every memory allocation. Without
5363** [SQLITE_ENABLE_MEMORY_MANAGEMENT], the soft heap limit is only enforced
5364** when memory is allocated by the page cache. Testing suggests that because
5365** the page cache is the predominate memory user in SQLite, most
5366** applications will achieve adequate soft heap limit enforcement without
5367** the use of [SQLITE_ENABLE_MEMORY_MANAGEMENT].
5368**
5369** The circumstances under which SQLite will enforce the soft heap limit may
5370** changes in future releases of SQLite.
5371*/
5372SQLITE_API sqlite3_int64 SQLITE_STDCALL sqlite3_soft_heap_limit64(sqlite3_int64 N);
5373
5374/*
5375** CAPI3REF: Deprecated Soft Heap Limit Interface
5376** DEPRECATED
5377**
5378** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
5379** interface. This routine is provided for historical compatibility
5380** only. All new applications should use the
5381** [sqlite3_soft_heap_limit64()] interface rather than this one.
5382*/
5383SQLITE_API SQLITE_DEPRECATED void SQLITE_STDCALL sqlite3_soft_heap_limit(int N);
5384
5385
5386/*
5387** CAPI3REF: Extract Metadata About A Column Of A Table
5388** METHOD: sqlite3
5389**
5390** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
5391** information about column C of table T in database D
5392** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
5393** interface returns SQLITE_OK and fills in the non-NULL pointers in
5394** the final five arguments with appropriate values if the specified
5395** column exists. ^The sqlite3_table_column_metadata() interface returns
5396** SQLITE_ERROR and if the specified column does not exist.
5397** ^If the column-name parameter to sqlite3_table_column_metadata() is a
5398** NULL pointer, then this routine simply checks for the existance of the
5399** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
5400** does not.
5401**
5402** ^The column is identified by the second, third and fourth parameters to
5403** this function. ^(The second parameter is either the name of the database
5404** (i.e. "main", "temp", or an attached database) containing the specified
5405** table or NULL.)^ ^If it is NULL, then all attached databases are searched
5406** for the table using the same algorithm used by the database engine to
5407** resolve unqualified table references.
5408**
5409** ^The third and fourth parameters to this function are the table and column
5410** name of the desired column, respectively.
5411**
5412** ^Metadata is returned by writing to the memory locations passed as the 5th
5413** and subsequent parameters to this function. ^Any of these arguments may be
5414** NULL, in which case the corresponding element of metadata is omitted.
5415**
5416** ^(<blockquote>
5417** <table border="1">
5418** <tr><th> Parameter <th> Output<br>Type <th> Description
5419**
5420** <tr><td> 5th <td> const char* <td> Data type
5421** <tr><td> 6th <td> const char* <td> Name of default collation sequence
5422** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
5423** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
5424** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
5425** </table>
5426** </blockquote>)^
5427**
5428** ^The memory pointed to by the character pointers returned for the
5429** declaration type and collation sequence is valid until the next
5430** call to any SQLite API function.
5431**
5432** ^If the specified table is actually a view, an [error code] is returned.
5433**
5434** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
5435** is not a [WITHOUT ROWID] table and an
5436** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
5437** parameters are set for the explicitly declared column. ^(If there is no
5438** [INTEGER PRIMARY KEY] column, then the outputs
5439** for the [rowid] are set as follows:
5440**
5441** <pre>
5442** data type: "INTEGER"
5443** collation sequence: "BINARY"
5444** not null: 0
5445** primary key: 1
5446** auto increment: 0
5447** </pre>)^
5448**
5449** ^This function causes all database schemas to be read from disk and
5450** parsed, if that has not already been done, and returns an error if
5451** any errors are encountered while loading the schema.
5452*/
5453SQLITE_API int SQLITE_STDCALL sqlite3_table_column_metadata(
5454 sqlite3 *db, /* Connection handle */
5455 const char *zDbName, /* Database name or NULL */
5456 const char *zTableName, /* Table name */
5457 const char *zColumnName, /* Column name */
5458 char const **pzDataType, /* OUTPUT: Declared data type */
5459 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
5460 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
5461 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
5462 int *pAutoinc /* OUTPUT: True if column is auto-increment */
5463);
5464
5465/*
5466** CAPI3REF: Load An Extension
5467** METHOD: sqlite3
5468**
5469** ^This interface loads an SQLite extension library from the named file.
5470**
5471** ^The sqlite3_load_extension() interface attempts to load an
5472** [SQLite extension] library contained in the file zFile. If
5473** the file cannot be loaded directly, attempts are made to load
5474** with various operating-system specific extensions added.
5475** So for example, if "samplelib" cannot be loaded, then names like
5476** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
5477** be tried also.
5478**
5479** ^The entry point is zProc.
5480** ^(zProc may be 0, in which case SQLite will try to come up with an
5481** entry point name on its own. It first tries "sqlite3_extension_init".
5482** If that does not work, it constructs a name "sqlite3_X_init" where the
5483** X is consists of the lower-case equivalent of all ASCII alphabetic
5484** characters in the filename from the last "/" to the first following
5485** "." and omitting any initial "lib".)^
5486** ^The sqlite3_load_extension() interface returns
5487** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
5488** ^If an error occurs and pzErrMsg is not 0, then the
5489** [sqlite3_load_extension()] interface shall attempt to
5490** fill *pzErrMsg with error message text stored in memory
5491** obtained from [sqlite3_malloc()]. The calling function
5492** should free this memory by calling [sqlite3_free()].
5493**
5494** ^Extension loading must be enabled using
5495** [sqlite3_enable_load_extension()] or
5496** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
5497** prior to calling this API,
5498** otherwise an error will be returned.
5499**
5500** <b>Security warning:</b> It is recommended that the
5501** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
5502** interface. The use of the [sqlite3_enable_load_extension()] interface
5503** should be avoided. This will keep the SQL function [load_extension()]
5504** disabled and prevent SQL injections from giving attackers
5505** access to extension loading capabilities.
5506**
5507** See also the [load_extension() SQL function].
5508*/
5509SQLITE_API int SQLITE_STDCALL sqlite3_load_extension(
5510 sqlite3 *db, /* Load the extension into this database connection */
5511 const char *zFile, /* Name of the shared library containing extension */
5512 const char *zProc, /* Entry point. Derived from zFile if 0 */
5513 char **pzErrMsg /* Put error message here if not 0 */
5514);
5515
5516/*
5517** CAPI3REF: Enable Or Disable Extension Loading
5518** METHOD: sqlite3
5519**
5520** ^So as not to open security holes in older applications that are
5521** unprepared to deal with [extension loading], and as a means of disabling
5522** [extension loading] while evaluating user-entered SQL, the following API
5523** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
5524**
5525** ^Extension loading is off by default.
5526** ^Call the sqlite3_enable_load_extension() routine with onoff==1
5527** to turn extension loading on and call it with onoff==0 to turn
5528** it back off again.
5529**
5530** ^This interface enables or disables both the C-API
5531** [sqlite3_load_extension()] and the SQL function [load_extension()].
5532** Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
5533** to enable or disable only the C-API.
5534**
5535** <b>Security warning:</b> It is recommended that extension loading
5536** be disabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
5537** rather than this interface, so the [load_extension()] SQL function
5538** remains disabled. This will prevent SQL injections from giving attackers
5539** access to extension loading capabilities.
5540*/
5541SQLITE_API int SQLITE_STDCALL sqlite3_enable_load_extension(sqlite3 *db, int onoff);
5542
5543/*
5544** CAPI3REF: Automatically Load Statically Linked Extensions
5545**
5546** ^This interface causes the xEntryPoint() function to be invoked for
5547** each new [database connection] that is created. The idea here is that
5548** xEntryPoint() is the entry point for a statically linked [SQLite extension]
5549** that is to be automatically loaded into all new database connections.
5550**
5551** ^(Even though the function prototype shows that xEntryPoint() takes
5552** no arguments and returns void, SQLite invokes xEntryPoint() with three
5553** arguments and expects and integer result as if the signature of the
5554** entry point where as follows:
5555**
5556** <blockquote><pre>
5557** int xEntryPoint(
5558** sqlite3 *db,
5559** const char **pzErrMsg,
5560** const struct sqlite3_api_routines *pThunk
5561** );
5562** </pre></blockquote>)^
5563**
5564** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
5565** point to an appropriate error message (obtained from [sqlite3_mprintf()])
5566** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
5567** is NULL before calling the xEntryPoint(). ^SQLite will invoke
5568** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
5569** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
5570** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
5571**
5572** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
5573** on the list of automatic extensions is a harmless no-op. ^No entry point
5574** will be called more than once for each database connection that is opened.
5575**
5576** See also: [sqlite3_reset_auto_extension()]
5577** and [sqlite3_cancel_auto_extension()]
5578*/
5579SQLITE_API int SQLITE_STDCALL sqlite3_auto_extension(void (*xEntryPoint)(void));
5580
5581/*
5582** CAPI3REF: Cancel Automatic Extension Loading
5583**
5584** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
5585** initialization routine X that was registered using a prior call to
5586** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
5587** routine returns 1 if initialization routine X was successfully
5588** unregistered and it returns 0 if X was not on the list of initialization
5589** routines.
5590*/
5591SQLITE_API int SQLITE_STDCALL sqlite3_cancel_auto_extension(void (*xEntryPoint)(void));
5592
5593/*
5594** CAPI3REF: Reset Automatic Extension Loading
5595**
5596** ^This interface disables all automatic extensions previously
5597** registered using [sqlite3_auto_extension()].
5598*/
5599SQLITE_API void SQLITE_STDCALL sqlite3_reset_auto_extension(void);
5600
5601/*
5602** The interface to the virtual-table mechanism is currently considered
5603** to be experimental. The interface might change in incompatible ways.
5604** If this is a problem for you, do not use the interface at this time.
5605**
5606** When the virtual-table mechanism stabilizes, we will declare the
5607** interface fixed, support it indefinitely, and remove this comment.
5608*/
5609
5610/*
5611** Structures used by the virtual table interface
5612*/
5613typedef struct sqlite3_vtab sqlite3_vtab;
5614typedef struct sqlite3_index_info sqlite3_index_info;
5615typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
5616typedef struct sqlite3_module sqlite3_module;
5617
5618/*
5619** CAPI3REF: Virtual Table Object
5620** KEYWORDS: sqlite3_module {virtual table module}
5621**
5622** This structure, sometimes called a "virtual table module",
5623** defines the implementation of a [virtual tables].
5624** This structure consists mostly of methods for the module.
5625**
5626** ^A virtual table module is created by filling in a persistent
5627** instance of this structure and passing a pointer to that instance
5628** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
5629** ^The registration remains valid until it is replaced by a different
5630** module or until the [database connection] closes. The content
5631** of this structure must not change while it is registered with
5632** any database connection.
5633*/
5634struct sqlite3_module {
5635 int iVersion;
5636 int (*xCreate)(sqlite3*, void *pAux,
5637 int argc, const char *const*argv,
5638 sqlite3_vtab **ppVTab, char**);
5639 int (*xConnect)(sqlite3*, void *pAux,
5640 int argc, const char *const*argv,
5641 sqlite3_vtab **ppVTab, char**);
5642 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
5643 int (*xDisconnect)(sqlite3_vtab *pVTab);
5644 int (*xDestroy)(sqlite3_vtab *pVTab);
5645 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
5646 int (*xClose)(sqlite3_vtab_cursor*);
5647 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
5648 int argc, sqlite3_value **argv);
5649 int (*xNext)(sqlite3_vtab_cursor*);
5650 int (*xEof)(sqlite3_vtab_cursor*);
5651 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
5652 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
5653 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
5654 int (*xBegin)(sqlite3_vtab *pVTab);
5655 int (*xSync)(sqlite3_vtab *pVTab);
5656 int (*xCommit)(sqlite3_vtab *pVTab);
5657 int (*xRollback)(sqlite3_vtab *pVTab);
5658 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
5659 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
5660 void **ppArg);
5661 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
5662 /* The methods above are in version 1 of the sqlite_module object. Those
5663 ** below are for version 2 and greater. */
5664 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
5665 int (*xRelease)(sqlite3_vtab *pVTab, int);
5666 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
5667};
5668
5669/*
5670** CAPI3REF: Virtual Table Indexing Information
5671** KEYWORDS: sqlite3_index_info
5672**
5673** The sqlite3_index_info structure and its substructures is used as part
5674** of the [virtual table] interface to
5675** pass information into and receive the reply from the [xBestIndex]
5676** method of a [virtual table module]. The fields under **Inputs** are the
5677** inputs to xBestIndex and are read-only. xBestIndex inserts its
5678** results into the **Outputs** fields.
5679**
5680** ^(The aConstraint[] array records WHERE clause constraints of the form:
5681**
5682** <blockquote>column OP expr</blockquote>
5683**
5684** where OP is =, <, <=, >, or >=.)^ ^(The particular operator is
5685** stored in aConstraint[].op using one of the
5686** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
5687** ^(The index of the column is stored in
5688** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
5689** expr on the right-hand side can be evaluated (and thus the constraint
5690** is usable) and false if it cannot.)^
5691**
5692** ^The optimizer automatically inverts terms of the form "expr OP column"
5693** and makes other simplifications to the WHERE clause in an attempt to
5694** get as many WHERE clause terms into the form shown above as possible.
5695** ^The aConstraint[] array only reports WHERE clause terms that are
5696** relevant to the particular virtual table being queried.
5697**
5698** ^Information about the ORDER BY clause is stored in aOrderBy[].
5699** ^Each term of aOrderBy records a column of the ORDER BY clause.
5700**
5701** The colUsed field indicates which columns of the virtual table may be
5702** required by the current scan. Virtual table columns are numbered from
5703** zero in the order in which they appear within the CREATE TABLE statement
5704** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
5705** the corresponding bit is set within the colUsed mask if the column may be
5706** required by SQLite. If the table has at least 64 columns and any column
5707** to the right of the first 63 is required, then bit 63 of colUsed is also
5708** set. In other words, column iCol may be required if the expression
5709** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
5710** non-zero.
5711**
5712** The [xBestIndex] method must fill aConstraintUsage[] with information
5713** about what parameters to pass to xFilter. ^If argvIndex>0 then
5714** the right-hand side of the corresponding aConstraint[] is evaluated
5715** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
5716** is true, then the constraint is assumed to be fully handled by the
5717** virtual table and is not checked again by SQLite.)^
5718**
5719** ^The idxNum and idxPtr values are recorded and passed into the
5720** [xFilter] method.
5721** ^[sqlite3_free()] is used to free idxPtr if and only if
5722** needToFreeIdxPtr is true.
5723**
5724** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
5725** the correct order to satisfy the ORDER BY clause so that no separate
5726** sorting step is required.
5727**
5728** ^The estimatedCost value is an estimate of the cost of a particular
5729** strategy. A cost of N indicates that the cost of the strategy is similar
5730** to a linear scan of an SQLite table with N rows. A cost of log(N)
5731** indicates that the expense of the operation is similar to that of a
5732** binary search on a unique indexed field of an SQLite table with N rows.
5733**
5734** ^The estimatedRows value is an estimate of the number of rows that
5735** will be returned by the strategy.
5736**
5737** The xBestIndex method may optionally populate the idxFlags field with a
5738** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
5739** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
5740** assumes that the strategy may visit at most one row.
5741**
5742** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
5743** SQLite also assumes that if a call to the xUpdate() method is made as
5744** part of the same statement to delete or update a virtual table row and the
5745** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
5746** any database changes. In other words, if the xUpdate() returns
5747** SQLITE_CONSTRAINT, the database contents must be exactly as they were
5748** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
5749** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
5750** the xUpdate method are automatically rolled back by SQLite.
5751**
5752** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
5753** structure for SQLite version 3.8.2. If a virtual table extension is
5754** used with an SQLite version earlier than 3.8.2, the results of attempting
5755** to read or write the estimatedRows field are undefined (but are likely
5756** to included crashing the application). The estimatedRows field should
5757** therefore only be used if [sqlite3_libversion_number()] returns a
5758** value greater than or equal to 3008002. Similarly, the idxFlags field
5759** was added for version 3.9.0. It may therefore only be used if
5760** sqlite3_libversion_number() returns a value greater than or equal to
5761** 3009000.
5762*/
5763struct sqlite3_index_info {
5764 /* Inputs */
5765 int nConstraint; /* Number of entries in aConstraint */
5766 struct sqlite3_index_constraint {
5767 int iColumn; /* Column constrained. -1 for ROWID */
5768 unsigned char op; /* Constraint operator */
5769 unsigned char usable; /* True if this constraint is usable */
5770 int iTermOffset; /* Used internally - xBestIndex should ignore */
5771 } *aConstraint; /* Table of WHERE clause constraints */
5772 int nOrderBy; /* Number of terms in the ORDER BY clause */
5773 struct sqlite3_index_orderby {
5774 int iColumn; /* Column number */
5775 unsigned char desc; /* True for DESC. False for ASC. */
5776 } *aOrderBy; /* The ORDER BY clause */
5777 /* Outputs */
5778 struct sqlite3_index_constraint_usage {
5779 int argvIndex; /* if >0, constraint is part of argv to xFilter */
5780 unsigned char omit; /* Do not code a test for this constraint */
5781 } *aConstraintUsage;
5782 int idxNum; /* Number used to identify the index */
5783 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
5784 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
5785 int orderByConsumed; /* True if output is already ordered */
5786 double estimatedCost; /* Estimated cost of using this index */
5787 /* Fields below are only available in SQLite 3.8.2 and later */
5788 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
5789 /* Fields below are only available in SQLite 3.9.0 and later */
5790 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
5791 /* Fields below are only available in SQLite 3.10.0 and later */
5792 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
5793};
5794
5795/*
5796** CAPI3REF: Virtual Table Scan Flags
5797*/
5798#define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
5799
5800/*
5801** CAPI3REF: Virtual Table Constraint Operator Codes
5802**
5803** These macros defined the allowed values for the
5804** [sqlite3_index_info].aConstraint[].op field. Each value represents
5805** an operator that is part of a constraint term in the wHERE clause of
5806** a query that uses a [virtual table].
5807*/
5808#define SQLITE_INDEX_CONSTRAINT_EQ 2
5809#define SQLITE_INDEX_CONSTRAINT_GT 4
5810#define SQLITE_INDEX_CONSTRAINT_LE 8
5811#define SQLITE_INDEX_CONSTRAINT_LT 16
5812#define SQLITE_INDEX_CONSTRAINT_GE 32
5813#define SQLITE_INDEX_CONSTRAINT_MATCH 64
5814#define SQLITE_INDEX_CONSTRAINT_LIKE 65
5815#define SQLITE_INDEX_CONSTRAINT_GLOB 66
5816#define SQLITE_INDEX_CONSTRAINT_REGEXP 67
5817
5818/*
5819** CAPI3REF: Register A Virtual Table Implementation
5820** METHOD: sqlite3
5821**
5822** ^These routines are used to register a new [virtual table module] name.
5823** ^Module names must be registered before
5824** creating a new [virtual table] using the module and before using a
5825** preexisting [virtual table] for the module.
5826**
5827** ^The module name is registered on the [database connection] specified
5828** by the first parameter. ^The name of the module is given by the
5829** second parameter. ^The third parameter is a pointer to
5830** the implementation of the [virtual table module]. ^The fourth
5831** parameter is an arbitrary client data pointer that is passed through
5832** into the [xCreate] and [xConnect] methods of the virtual table module
5833** when a new virtual table is be being created or reinitialized.
5834**
5835** ^The sqlite3_create_module_v2() interface has a fifth parameter which
5836** is a pointer to a destructor for the pClientData. ^SQLite will
5837** invoke the destructor function (if it is not NULL) when SQLite
5838** no longer needs the pClientData pointer. ^The destructor will also
5839** be invoked if the call to sqlite3_create_module_v2() fails.
5840** ^The sqlite3_create_module()
5841** interface is equivalent to sqlite3_create_module_v2() with a NULL
5842** destructor.
5843*/
5844SQLITE_API int SQLITE_STDCALL sqlite3_create_module(
5845 sqlite3 *db, /* SQLite connection to register module with */
5846 const char *zName, /* Name of the module */
5847 const sqlite3_module *p, /* Methods for the module */
5848 void *pClientData /* Client data for xCreate/xConnect */
5849);
5850SQLITE_API int SQLITE_STDCALL sqlite3_create_module_v2(
5851 sqlite3 *db, /* SQLite connection to register module with */
5852 const char *zName, /* Name of the module */
5853 const sqlite3_module *p, /* Methods for the module */
5854 void *pClientData, /* Client data for xCreate/xConnect */
5855 void(*xDestroy)(void*) /* Module destructor function */
5856);
5857
5858/*
5859** CAPI3REF: Virtual Table Instance Object
5860** KEYWORDS: sqlite3_vtab
5861**
5862** Every [virtual table module] implementation uses a subclass
5863** of this object to describe a particular instance
5864** of the [virtual table]. Each subclass will
5865** be tailored to the specific needs of the module implementation.
5866** The purpose of this superclass is to define certain fields that are
5867** common to all module implementations.
5868**
5869** ^Virtual tables methods can set an error message by assigning a
5870** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
5871** take care that any prior string is freed by a call to [sqlite3_free()]
5872** prior to assigning a new string to zErrMsg. ^After the error message
5873** is delivered up to the client application, the string will be automatically
5874** freed by sqlite3_free() and the zErrMsg field will be zeroed.
5875*/
5876struct sqlite3_vtab {
5877 const sqlite3_module *pModule; /* The module for this virtual table */
5878 int nRef; /* Number of open cursors */
5879 char *zErrMsg; /* Error message from sqlite3_mprintf() */
5880 /* Virtual table implementations will typically add additional fields */
5881};
5882
5883/*
5884** CAPI3REF: Virtual Table Cursor Object
5885** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
5886**
5887** Every [virtual table module] implementation uses a subclass of the
5888** following structure to describe cursors that point into the
5889** [virtual table] and are used
5890** to loop through the virtual table. Cursors are created using the
5891** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
5892** by the [sqlite3_module.xClose | xClose] method. Cursors are used
5893** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
5894** of the module. Each module implementation will define
5895** the content of a cursor structure to suit its own needs.
5896**
5897** This superclass exists in order to define fields of the cursor that
5898** are common to all implementations.
5899*/
5900struct sqlite3_vtab_cursor {
5901 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
5902 /* Virtual table implementations will typically add additional fields */
5903};
5904
5905/*
5906** CAPI3REF: Declare The Schema Of A Virtual Table
5907**
5908** ^The [xCreate] and [xConnect] methods of a
5909** [virtual table module] call this interface
5910** to declare the format (the names and datatypes of the columns) of
5911** the virtual tables they implement.
5912*/
5913SQLITE_API int SQLITE_STDCALL sqlite3_declare_vtab(sqlite3*, const char *zSQL);
5914
5915/*
5916** CAPI3REF: Overload A Function For A Virtual Table
5917** METHOD: sqlite3
5918**
5919** ^(Virtual tables can provide alternative implementations of functions
5920** using the [xFindFunction] method of the [virtual table module].
5921** But global versions of those functions
5922** must exist in order to be overloaded.)^
5923**
5924** ^(This API makes sure a global version of a function with a particular
5925** name and number of parameters exists. If no such function exists
5926** before this API is called, a new function is created.)^ ^The implementation
5927** of the new function always causes an exception to be thrown. So
5928** the new function is not good for anything by itself. Its only
5929** purpose is to be a placeholder function that can be overloaded
5930** by a [virtual table].
5931*/
5932SQLITE_API int SQLITE_STDCALL sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
5933
5934/*
5935** The interface to the virtual-table mechanism defined above (back up
5936** to a comment remarkably similar to this one) is currently considered
5937** to be experimental. The interface might change in incompatible ways.
5938** If this is a problem for you, do not use the interface at this time.
5939**
5940** When the virtual-table mechanism stabilizes, we will declare the
5941** interface fixed, support it indefinitely, and remove this comment.
5942*/
5943
5944/*
5945** CAPI3REF: A Handle To An Open BLOB
5946** KEYWORDS: {BLOB handle} {BLOB handles}
5947**
5948** An instance of this object represents an open BLOB on which
5949** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
5950** ^Objects of this type are created by [sqlite3_blob_open()]
5951** and destroyed by [sqlite3_blob_close()].
5952** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
5953** can be used to read or write small subsections of the BLOB.
5954** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
5955*/
5956typedef struct sqlite3_blob sqlite3_blob;
5957
5958/*
5959** CAPI3REF: Open A BLOB For Incremental I/O
5960** METHOD: sqlite3
5961** CONSTRUCTOR: sqlite3_blob
5962**
5963** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
5964** in row iRow, column zColumn, table zTable in database zDb;
5965** in other words, the same BLOB that would be selected by:
5966**
5967** <pre>
5968** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
5969** </pre>)^
5970**
5971** ^(Parameter zDb is not the filename that contains the database, but
5972** rather the symbolic name of the database. For attached databases, this is
5973** the name that appears after the AS keyword in the [ATTACH] statement.
5974** For the main database file, the database name is "main". For TEMP
5975** tables, the database name is "temp".)^
5976**
5977** ^If the flags parameter is non-zero, then the BLOB is opened for read
5978** and write access. ^If the flags parameter is zero, the BLOB is opened for
5979** read-only access.
5980**
5981** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
5982** in *ppBlob. Otherwise an [error code] is returned and, unless the error
5983** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
5984** the API is not misused, it is always safe to call [sqlite3_blob_close()]
5985** on *ppBlob after this function it returns.
5986**
5987** This function fails with SQLITE_ERROR if any of the following are true:
5988** <ul>
5989** <li> ^(Database zDb does not exist)^,
5990** <li> ^(Table zTable does not exist within database zDb)^,
5991** <li> ^(Table zTable is a WITHOUT ROWID table)^,
5992** <li> ^(Column zColumn does not exist)^,
5993** <li> ^(Row iRow is not present in the table)^,
5994** <li> ^(The specified column of row iRow contains a value that is not
5995** a TEXT or BLOB value)^,
5996** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
5997** constraint and the blob is being opened for read/write access)^,
5998** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
5999** column zColumn is part of a [child key] definition and the blob is
6000** being opened for read/write access)^.
6001** </ul>
6002**
6003** ^Unless it returns SQLITE_MISUSE, this function sets the
6004** [database connection] error code and message accessible via
6005** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6006**
6007**
6008** ^(If the row that a BLOB handle points to is modified by an
6009** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
6010** then the BLOB handle is marked as "expired".
6011** This is true if any column of the row is changed, even a column
6012** other than the one the BLOB handle is open on.)^
6013** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
6014** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
6015** ^(Changes written into a BLOB prior to the BLOB expiring are not
6016** rolled back by the expiration of the BLOB. Such changes will eventually
6017** commit if the transaction continues to completion.)^
6018**
6019** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
6020** the opened blob. ^The size of a blob may not be changed by this
6021** interface. Use the [UPDATE] SQL command to change the size of a
6022** blob.
6023**
6024** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
6025** and the built-in [zeroblob] SQL function may be used to create a
6026** zero-filled blob to read or write using the incremental-blob interface.
6027**
6028** To avoid a resource leak, every open [BLOB handle] should eventually
6029** be released by a call to [sqlite3_blob_close()].
6030*/
6031SQLITE_API int SQLITE_STDCALL sqlite3_blob_open(
6032 sqlite3*,
6033 const char *zDb,
6034 const char *zTable,
6035 const char *zColumn,
6036 sqlite3_int64 iRow,
6037 int flags,
6038 sqlite3_blob **ppBlob
6039);
6040
6041/*
6042** CAPI3REF: Move a BLOB Handle to a New Row
6043** METHOD: sqlite3_blob
6044**
6045** ^This function is used to move an existing blob handle so that it points
6046** to a different row of the same database table. ^The new row is identified
6047** by the rowid value passed as the second argument. Only the row can be
6048** changed. ^The database, table and column on which the blob handle is open
6049** remain the same. Moving an existing blob handle to a new row can be
6050** faster than closing the existing handle and opening a new one.
6051**
6052** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
6053** it must exist and there must be either a blob or text value stored in
6054** the nominated column.)^ ^If the new row is not present in the table, or if
6055** it does not contain a blob or text value, or if another error occurs, an
6056** SQLite error code is returned and the blob handle is considered aborted.
6057** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
6058** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
6059** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
6060** always returns zero.
6061**
6062** ^This function sets the database handle error code and message.
6063*/
6064SQLITE_API int SQLITE_STDCALL sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
6065
6066/*
6067** CAPI3REF: Close A BLOB Handle
6068** DESTRUCTOR: sqlite3_blob
6069**
6070** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
6071** unconditionally. Even if this routine returns an error code, the
6072** handle is still closed.)^
6073**
6074** ^If the blob handle being closed was opened for read-write access, and if
6075** the database is in auto-commit mode and there are no other open read-write
6076** blob handles or active write statements, the current transaction is
6077** committed. ^If an error occurs while committing the transaction, an error
6078** code is returned and the transaction rolled back.
6079**
6080** Calling this function with an argument that is not a NULL pointer or an
6081** open blob handle results in undefined behaviour. ^Calling this routine
6082** with a null pointer (such as would be returned by a failed call to
6083** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
6084** is passed a valid open blob handle, the values returned by the
6085** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
6086*/
6087SQLITE_API int SQLITE_STDCALL sqlite3_blob_close(sqlite3_blob *);
6088
6089/*
6090** CAPI3REF: Return The Size Of An Open BLOB
6091** METHOD: sqlite3_blob
6092**
6093** ^Returns the size in bytes of the BLOB accessible via the
6094** successfully opened [BLOB handle] in its only argument. ^The
6095** incremental blob I/O routines can only read or overwriting existing
6096** blob content; they cannot change the size of a blob.
6097**
6098** This routine only works on a [BLOB handle] which has been created
6099** by a prior successful call to [sqlite3_blob_open()] and which has not
6100** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6101** to this routine results in undefined and probably undesirable behavior.
6102*/
6103SQLITE_API int SQLITE_STDCALL sqlite3_blob_bytes(sqlite3_blob *);
6104
6105/*
6106** CAPI3REF: Read Data From A BLOB Incrementally
6107** METHOD: sqlite3_blob
6108**
6109** ^(This function is used to read data from an open [BLOB handle] into a
6110** caller-supplied buffer. N bytes of data are copied into buffer Z
6111** from the open BLOB, starting at offset iOffset.)^
6112**
6113** ^If offset iOffset is less than N bytes from the end of the BLOB,
6114** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
6115** less than zero, [SQLITE_ERROR] is returned and no data is read.
6116** ^The size of the blob (and hence the maximum value of N+iOffset)
6117** can be determined using the [sqlite3_blob_bytes()] interface.
6118**
6119** ^An attempt to read from an expired [BLOB handle] fails with an
6120** error code of [SQLITE_ABORT].
6121**
6122** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
6123** Otherwise, an [error code] or an [extended error code] is returned.)^
6124**
6125** This routine only works on a [BLOB handle] which has been created
6126** by a prior successful call to [sqlite3_blob_open()] and which has not
6127** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6128** to this routine results in undefined and probably undesirable behavior.
6129**
6130** See also: [sqlite3_blob_write()].
6131*/
6132SQLITE_API int SQLITE_STDCALL sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
6133
6134/*
6135** CAPI3REF: Write Data Into A BLOB Incrementally
6136** METHOD: sqlite3_blob
6137**
6138** ^(This function is used to write data into an open [BLOB handle] from a
6139** caller-supplied buffer. N bytes of data are copied from the buffer Z
6140** into the open BLOB, starting at offset iOffset.)^
6141**
6142** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
6143** Otherwise, an [error code] or an [extended error code] is returned.)^
6144** ^Unless SQLITE_MISUSE is returned, this function sets the
6145** [database connection] error code and message accessible via
6146** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
6147**
6148** ^If the [BLOB handle] passed as the first argument was not opened for
6149** writing (the flags parameter to [sqlite3_blob_open()] was zero),
6150** this function returns [SQLITE_READONLY].
6151**
6152** This function may only modify the contents of the BLOB; it is
6153** not possible to increase the size of a BLOB using this API.
6154** ^If offset iOffset is less than N bytes from the end of the BLOB,
6155** [SQLITE_ERROR] is returned and no data is written. The size of the
6156** BLOB (and hence the maximum value of N+iOffset) can be determined
6157** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
6158** than zero [SQLITE_ERROR] is returned and no data is written.
6159**
6160** ^An attempt to write to an expired [BLOB handle] fails with an
6161** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
6162** before the [BLOB handle] expired are not rolled back by the
6163** expiration of the handle, though of course those changes might
6164** have been overwritten by the statement that expired the BLOB handle
6165** or by other independent statements.
6166**
6167** This routine only works on a [BLOB handle] which has been created
6168** by a prior successful call to [sqlite3_blob_open()] and which has not
6169** been closed by [sqlite3_blob_close()]. Passing any other pointer in
6170** to this routine results in undefined and probably undesirable behavior.
6171**
6172** See also: [sqlite3_blob_read()].
6173*/
6174SQLITE_API int SQLITE_STDCALL sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
6175
6176/*
6177** CAPI3REF: Virtual File System Objects
6178**
6179** A virtual filesystem (VFS) is an [sqlite3_vfs] object
6180** that SQLite uses to interact
6181** with the underlying operating system. Most SQLite builds come with a
6182** single default VFS that is appropriate for the host computer.
6183** New VFSes can be registered and existing VFSes can be unregistered.
6184** The following interfaces are provided.
6185**
6186** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
6187** ^Names are case sensitive.
6188** ^Names are zero-terminated UTF-8 strings.
6189** ^If there is no match, a NULL pointer is returned.
6190** ^If zVfsName is NULL then the default VFS is returned.
6191**
6192** ^New VFSes are registered with sqlite3_vfs_register().
6193** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
6194** ^The same VFS can be registered multiple times without injury.
6195** ^To make an existing VFS into the default VFS, register it again
6196** with the makeDflt flag set. If two different VFSes with the
6197** same name are registered, the behavior is undefined. If a
6198** VFS is registered with a name that is NULL or an empty string,
6199** then the behavior is undefined.
6200**
6201** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
6202** ^(If the default VFS is unregistered, another VFS is chosen as
6203** the default. The choice for the new VFS is arbitrary.)^
6204*/
6205SQLITE_API sqlite3_vfs *SQLITE_STDCALL sqlite3_vfs_find(const char *zVfsName);
6206SQLITE_API int SQLITE_STDCALL sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
6207SQLITE_API int SQLITE_STDCALL sqlite3_vfs_unregister(sqlite3_vfs*);
6208
6209/*
6210** CAPI3REF: Mutexes
6211**
6212** The SQLite core uses these routines for thread
6213** synchronization. Though they are intended for internal
6214** use by SQLite, code that links against SQLite is
6215** permitted to use any of these routines.
6216**
6217** The SQLite source code contains multiple implementations
6218** of these mutex routines. An appropriate implementation
6219** is selected automatically at compile-time. The following
6220** implementations are available in the SQLite core:
6221**
6222** <ul>
6223** <li> SQLITE_MUTEX_PTHREADS
6224** <li> SQLITE_MUTEX_W32
6225** <li> SQLITE_MUTEX_NOOP
6226** </ul>
6227**
6228** The SQLITE_MUTEX_NOOP implementation is a set of routines
6229** that does no real locking and is appropriate for use in
6230** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
6231** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
6232** and Windows.
6233**
6234** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
6235** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
6236** implementation is included with the library. In this case the
6237** application must supply a custom mutex implementation using the
6238** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
6239** before calling sqlite3_initialize() or any other public sqlite3_
6240** function that calls sqlite3_initialize().
6241**
6242** ^The sqlite3_mutex_alloc() routine allocates a new
6243** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
6244** routine returns NULL if it is unable to allocate the requested
6245** mutex. The argument to sqlite3_mutex_alloc() must one of these
6246** integer constants:
6247**
6248** <ul>
6249** <li> SQLITE_MUTEX_FAST
6250** <li> SQLITE_MUTEX_RECURSIVE
6251** <li> SQLITE_MUTEX_STATIC_MASTER
6252** <li> SQLITE_MUTEX_STATIC_MEM
6253** <li> SQLITE_MUTEX_STATIC_OPEN
6254** <li> SQLITE_MUTEX_STATIC_PRNG
6255** <li> SQLITE_MUTEX_STATIC_LRU
6256** <li> SQLITE_MUTEX_STATIC_PMEM
6257** <li> SQLITE_MUTEX_STATIC_APP1
6258** <li> SQLITE_MUTEX_STATIC_APP2
6259** <li> SQLITE_MUTEX_STATIC_APP3
6260** <li> SQLITE_MUTEX_STATIC_VFS1
6261** <li> SQLITE_MUTEX_STATIC_VFS2
6262** <li> SQLITE_MUTEX_STATIC_VFS3
6263** </ul>
6264**
6265** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
6266** cause sqlite3_mutex_alloc() to create
6267** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
6268** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
6269** The mutex implementation does not need to make a distinction
6270** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
6271** not want to. SQLite will only request a recursive mutex in
6272** cases where it really needs one. If a faster non-recursive mutex
6273** implementation is available on the host platform, the mutex subsystem
6274** might return such a mutex in response to SQLITE_MUTEX_FAST.
6275**
6276** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
6277** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
6278** a pointer to a static preexisting mutex. ^Nine static mutexes are
6279** used by the current version of SQLite. Future versions of SQLite
6280** may add additional static mutexes. Static mutexes are for internal
6281** use by SQLite only. Applications that use SQLite mutexes should
6282** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
6283** SQLITE_MUTEX_RECURSIVE.
6284**
6285** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
6286** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
6287** returns a different mutex on every call. ^For the static
6288** mutex types, the same mutex is returned on every call that has
6289** the same type number.
6290**
6291** ^The sqlite3_mutex_free() routine deallocates a previously
6292** allocated dynamic mutex. Attempting to deallocate a static
6293** mutex results in undefined behavior.
6294**
6295** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
6296** to enter a mutex. ^If another thread is already within the mutex,
6297** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
6298** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
6299** upon successful entry. ^(Mutexes created using
6300** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
6301** In such cases, the
6302** mutex must be exited an equal number of times before another thread
6303** can enter.)^ If the same thread tries to enter any mutex other
6304** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
6305**
6306** ^(Some systems (for example, Windows 95) do not support the operation
6307** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
6308** will always return SQLITE_BUSY. The SQLite core only ever uses
6309** sqlite3_mutex_try() as an optimization so this is acceptable
6310** behavior.)^
6311**
6312** ^The sqlite3_mutex_leave() routine exits a mutex that was
6313** previously entered by the same thread. The behavior
6314** is undefined if the mutex is not currently entered by the
6315** calling thread or is not currently allocated.
6316**
6317** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(), or
6318** sqlite3_mutex_leave() is a NULL pointer, then all three routines
6319** behave as no-ops.
6320**
6321** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
6322*/
6323SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_mutex_alloc(int);
6324SQLITE_API void SQLITE_STDCALL sqlite3_mutex_free(sqlite3_mutex*);
6325SQLITE_API void SQLITE_STDCALL sqlite3_mutex_enter(sqlite3_mutex*);
6326SQLITE_API int SQLITE_STDCALL sqlite3_mutex_try(sqlite3_mutex*);
6327SQLITE_API void SQLITE_STDCALL sqlite3_mutex_leave(sqlite3_mutex*);
6328
6329/*
6330** CAPI3REF: Mutex Methods Object
6331**
6332** An instance of this structure defines the low-level routines
6333** used to allocate and use mutexes.
6334**
6335** Usually, the default mutex implementations provided by SQLite are
6336** sufficient, however the application has the option of substituting a custom
6337** implementation for specialized deployments or systems for which SQLite
6338** does not provide a suitable implementation. In this case, the application
6339** creates and populates an instance of this structure to pass
6340** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
6341** Additionally, an instance of this structure can be used as an
6342** output variable when querying the system for the current mutex
6343** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
6344**
6345** ^The xMutexInit method defined by this structure is invoked as
6346** part of system initialization by the sqlite3_initialize() function.
6347** ^The xMutexInit routine is called by SQLite exactly once for each
6348** effective call to [sqlite3_initialize()].
6349**
6350** ^The xMutexEnd method defined by this structure is invoked as
6351** part of system shutdown by the sqlite3_shutdown() function. The
6352** implementation of this method is expected to release all outstanding
6353** resources obtained by the mutex methods implementation, especially
6354** those obtained by the xMutexInit method. ^The xMutexEnd()
6355** interface is invoked exactly once for each call to [sqlite3_shutdown()].
6356**
6357** ^(The remaining seven methods defined by this structure (xMutexAlloc,
6358** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
6359** xMutexNotheld) implement the following interfaces (respectively):
6360**
6361** <ul>
6362** <li> [sqlite3_mutex_alloc()] </li>
6363** <li> [sqlite3_mutex_free()] </li>
6364** <li> [sqlite3_mutex_enter()] </li>
6365** <li> [sqlite3_mutex_try()] </li>
6366** <li> [sqlite3_mutex_leave()] </li>
6367** <li> [sqlite3_mutex_held()] </li>
6368** <li> [sqlite3_mutex_notheld()] </li>
6369** </ul>)^
6370**
6371** The only difference is that the public sqlite3_XXX functions enumerated
6372** above silently ignore any invocations that pass a NULL pointer instead
6373** of a valid mutex handle. The implementations of the methods defined
6374** by this structure are not required to handle this case, the results
6375** of passing a NULL pointer instead of a valid mutex handle are undefined
6376** (i.e. it is acceptable to provide an implementation that segfaults if
6377** it is passed a NULL pointer).
6378**
6379** The xMutexInit() method must be threadsafe. It must be harmless to
6380** invoke xMutexInit() multiple times within the same process and without
6381** intervening calls to xMutexEnd(). Second and subsequent calls to
6382** xMutexInit() must be no-ops.
6383**
6384** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
6385** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
6386** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
6387** memory allocation for a fast or recursive mutex.
6388**
6389** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
6390** called, but only if the prior call to xMutexInit returned SQLITE_OK.
6391** If xMutexInit fails in any way, it is expected to clean up after itself
6392** prior to returning.
6393*/
6394typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
6395struct sqlite3_mutex_methods {
6396 int (*xMutexInit)(void);
6397 int (*xMutexEnd)(void);
6398 sqlite3_mutex *(*xMutexAlloc)(int);
6399 void (*xMutexFree)(sqlite3_mutex *);
6400 void (*xMutexEnter)(sqlite3_mutex *);
6401 int (*xMutexTry)(sqlite3_mutex *);
6402 void (*xMutexLeave)(sqlite3_mutex *);
6403 int (*xMutexHeld)(sqlite3_mutex *);
6404 int (*xMutexNotheld)(sqlite3_mutex *);
6405};
6406
6407/*
6408** CAPI3REF: Mutex Verification Routines
6409**
6410** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
6411** are intended for use inside assert() statements. The SQLite core
6412** never uses these routines except inside an assert() and applications
6413** are advised to follow the lead of the core. The SQLite core only
6414** provides implementations for these routines when it is compiled
6415** with the SQLITE_DEBUG flag. External mutex implementations
6416** are only required to provide these routines if SQLITE_DEBUG is
6417** defined and if NDEBUG is not defined.
6418**
6419** These routines should return true if the mutex in their argument
6420** is held or not held, respectively, by the calling thread.
6421**
6422** The implementation is not required to provide versions of these
6423** routines that actually work. If the implementation does not provide working
6424** versions of these routines, it should at least provide stubs that always
6425** return true so that one does not get spurious assertion failures.
6426**
6427** If the argument to sqlite3_mutex_held() is a NULL pointer then
6428** the routine should return 1. This seems counter-intuitive since
6429** clearly the mutex cannot be held if it does not exist. But
6430** the reason the mutex does not exist is because the build is not
6431** using mutexes. And we do not want the assert() containing the
6432** call to sqlite3_mutex_held() to fail, so a non-zero return is
6433** the appropriate thing to do. The sqlite3_mutex_notheld()
6434** interface should also return 1 when given a NULL pointer.
6435*/
6436#ifndef NDEBUG
6437SQLITE_API int SQLITE_STDCALL sqlite3_mutex_held(sqlite3_mutex*);
6438SQLITE_API int SQLITE_STDCALL sqlite3_mutex_notheld(sqlite3_mutex*);
6439#endif
6440
6441/*
6442** CAPI3REF: Mutex Types
6443**
6444** The [sqlite3_mutex_alloc()] interface takes a single argument
6445** which is one of these integer constants.
6446**
6447** The set of static mutexes may change from one SQLite release to the
6448** next. Applications that override the built-in mutex logic must be
6449** prepared to accommodate additional static mutexes.
6450*/
6451#define SQLITE_MUTEX_FAST 0
6452#define SQLITE_MUTEX_RECURSIVE 1
6453#define SQLITE_MUTEX_STATIC_MASTER 2
6454#define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
6455#define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
6456#define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
6457#define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_random() */
6458#define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
6459#define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
6460#define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
6461#define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
6462#define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
6463#define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
6464#define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
6465#define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
6466#define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
6467
6468/*
6469** CAPI3REF: Retrieve the mutex for a database connection
6470** METHOD: sqlite3
6471**
6472** ^This interface returns a pointer the [sqlite3_mutex] object that
6473** serializes access to the [database connection] given in the argument
6474** when the [threading mode] is Serialized.
6475** ^If the [threading mode] is Single-thread or Multi-thread then this
6476** routine returns a NULL pointer.
6477*/
6478SQLITE_API sqlite3_mutex *SQLITE_STDCALL sqlite3_db_mutex(sqlite3*);
6479
6480/*
6481** CAPI3REF: Low-Level Control Of Database Files
6482** METHOD: sqlite3
6483**
6484** ^The [sqlite3_file_control()] interface makes a direct call to the
6485** xFileControl method for the [sqlite3_io_methods] object associated
6486** with a particular database identified by the second argument. ^The
6487** name of the database is "main" for the main database or "temp" for the
6488** TEMP database, or the name that appears after the AS keyword for
6489** databases that are added using the [ATTACH] SQL command.
6490** ^A NULL pointer can be used in place of "main" to refer to the
6491** main database file.
6492** ^The third and fourth parameters to this routine
6493** are passed directly through to the second and third parameters of
6494** the xFileControl method. ^The return value of the xFileControl
6495** method becomes the return value of this routine.
6496**
6497** ^The SQLITE_FCNTL_FILE_POINTER value for the op parameter causes
6498** a pointer to the underlying [sqlite3_file] object to be written into
6499** the space pointed to by the 4th parameter. ^The SQLITE_FCNTL_FILE_POINTER
6500** case is a short-circuit path which does not actually invoke the
6501** underlying sqlite3_io_methods.xFileControl method.
6502**
6503** ^If the second parameter (zDbName) does not match the name of any
6504** open database file, then SQLITE_ERROR is returned. ^This error
6505** code is not remembered and will not be recalled by [sqlite3_errcode()]
6506** or [sqlite3_errmsg()]. The underlying xFileControl method might
6507** also return SQLITE_ERROR. There is no way to distinguish between
6508** an incorrect zDbName and an SQLITE_ERROR return from the underlying
6509** xFileControl method.
6510**
6511** See also: [SQLITE_FCNTL_LOCKSTATE]
6512*/
6513SQLITE_API int SQLITE_STDCALL sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
6514
6515/*
6516** CAPI3REF: Testing Interface
6517**
6518** ^The sqlite3_test_control() interface is used to read out internal
6519** state of SQLite and to inject faults into SQLite for testing
6520** purposes. ^The first parameter is an operation code that determines
6521** the number, meaning, and operation of all subsequent parameters.
6522**
6523** This interface is not for use by applications. It exists solely
6524** for verifying the correct operation of the SQLite library. Depending
6525** on how the SQLite library is compiled, this interface might not exist.
6526**
6527** The details of the operation codes, their meanings, the parameters
6528** they take, and what they do are all subject to change without notice.
6529** Unlike most of the SQLite API, this function is not guaranteed to
6530** operate consistently from one release to the next.
6531*/
6532SQLITE_API int SQLITE_CDECL sqlite3_test_control(int op, ...);
6533
6534/*
6535** CAPI3REF: Testing Interface Operation Codes
6536**
6537** These constants are the valid operation code parameters used
6538** as the first argument to [sqlite3_test_control()].
6539**
6540** These parameters and their meanings are subject to change
6541** without notice. These values are for testing purposes only.
6542** Applications should not use any of these parameters or the
6543** [sqlite3_test_control()] interface.
6544*/
6545#define SQLITE_TESTCTRL_FIRST 5
6546#define SQLITE_TESTCTRL_PRNG_SAVE 5
6547#define SQLITE_TESTCTRL_PRNG_RESTORE 6
6548#define SQLITE_TESTCTRL_PRNG_RESET 7
6549#define SQLITE_TESTCTRL_BITVEC_TEST 8
6550#define SQLITE_TESTCTRL_FAULT_INSTALL 9
6551#define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
6552#define SQLITE_TESTCTRL_PENDING_BYTE 11
6553#define SQLITE_TESTCTRL_ASSERT 12
6554#define SQLITE_TESTCTRL_ALWAYS 13
6555#define SQLITE_TESTCTRL_RESERVE 14
6556#define SQLITE_TESTCTRL_OPTIMIZATIONS 15
6557#define SQLITE_TESTCTRL_ISKEYWORD 16
6558#define SQLITE_TESTCTRL_SCRATCHMALLOC 17
6559#define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
6560#define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
6561#define SQLITE_TESTCTRL_NEVER_CORRUPT 20
6562#define SQLITE_TESTCTRL_VDBE_COVERAGE 21
6563#define SQLITE_TESTCTRL_BYTEORDER 22
6564#define SQLITE_TESTCTRL_ISINIT 23
6565#define SQLITE_TESTCTRL_SORTER_MMAP 24
6566#define SQLITE_TESTCTRL_IMPOSTER 25
6567#define SQLITE_TESTCTRL_LAST 25
6568
6569/*
6570** CAPI3REF: SQLite Runtime Status
6571**
6572** ^These interfaces are used to retrieve runtime status information
6573** about the performance of SQLite, and optionally to reset various
6574** highwater marks. ^The first argument is an integer code for
6575** the specific parameter to measure. ^(Recognized integer codes
6576** are of the form [status parameters | SQLITE_STATUS_...].)^
6577** ^The current value of the parameter is returned into *pCurrent.
6578** ^The highest recorded value is returned in *pHighwater. ^If the
6579** resetFlag is true, then the highest record value is reset after
6580** *pHighwater is written. ^(Some parameters do not record the highest
6581** value. For those parameters
6582** nothing is written into *pHighwater and the resetFlag is ignored.)^
6583** ^(Other parameters record only the highwater mark and not the current
6584** value. For these latter parameters nothing is written into *pCurrent.)^
6585**
6586** ^The sqlite3_status() and sqlite3_status64() routines return
6587** SQLITE_OK on success and a non-zero [error code] on failure.
6588**
6589** If either the current value or the highwater mark is too large to
6590** be represented by a 32-bit integer, then the values returned by
6591** sqlite3_status() are undefined.
6592**
6593** See also: [sqlite3_db_status()]
6594*/
6595SQLITE_API int SQLITE_STDCALL sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
6596SQLITE_API int SQLITE_STDCALL sqlite3_status64(
6597 int op,
6598 sqlite3_int64 *pCurrent,
6599 sqlite3_int64 *pHighwater,
6600 int resetFlag
6601);
6602
6603
6604/*
6605** CAPI3REF: Status Parameters
6606** KEYWORDS: {status parameters}
6607**
6608** These integer constants designate various run-time status parameters
6609** that can be returned by [sqlite3_status()].
6610**
6611** <dl>
6612** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
6613** <dd>This parameter is the current amount of memory checked out
6614** using [sqlite3_malloc()], either directly or indirectly. The
6615** figure includes calls made to [sqlite3_malloc()] by the application
6616** and internal memory usage by the SQLite library. Scratch memory
6617** controlled by [SQLITE_CONFIG_SCRATCH] and auxiliary page-cache
6618** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
6619** this parameter. The amount returned is the sum of the allocation
6620** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
6621**
6622** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
6623** <dd>This parameter records the largest memory allocation request
6624** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
6625** internal equivalents). Only the value returned in the
6626** *pHighwater parameter to [sqlite3_status()] is of interest.
6627** The value written into the *pCurrent parameter is undefined.</dd>)^
6628**
6629** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
6630** <dd>This parameter records the number of separate memory allocations
6631** currently checked out.</dd>)^
6632**
6633** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
6634** <dd>This parameter returns the number of pages used out of the
6635** [pagecache memory allocator] that was configured using
6636** [SQLITE_CONFIG_PAGECACHE]. The
6637** value returned is in pages, not in bytes.</dd>)^
6638**
6639** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
6640** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
6641** <dd>This parameter returns the number of bytes of page cache
6642** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
6643** buffer and where forced to overflow to [sqlite3_malloc()]. The
6644** returned value includes allocations that overflowed because they
6645** where too large (they were larger than the "sz" parameter to
6646** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
6647** no space was left in the page cache.</dd>)^
6648**
6649** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
6650** <dd>This parameter records the largest memory allocation request
6651** handed to [pagecache memory allocator]. Only the value returned in the
6652** *pHighwater parameter to [sqlite3_status()] is of interest.
6653** The value written into the *pCurrent parameter is undefined.</dd>)^
6654**
6655** [[SQLITE_STATUS_SCRATCH_USED]] ^(<dt>SQLITE_STATUS_SCRATCH_USED</dt>
6656** <dd>This parameter returns the number of allocations used out of the
6657** [scratch memory allocator] configured using
6658** [SQLITE_CONFIG_SCRATCH]. The value returned is in allocations, not
6659** in bytes. Since a single thread may only have one scratch allocation
6660** outstanding at time, this parameter also reports the number of threads
6661** using scratch memory at the same time.</dd>)^
6662**
6663** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
6664** <dd>This parameter returns the number of bytes of scratch memory
6665** allocation which could not be satisfied by the [SQLITE_CONFIG_SCRATCH]
6666** buffer and where forced to overflow to [sqlite3_malloc()]. The values
6667** returned include overflows because the requested allocation was too
6668** larger (that is, because the requested allocation was larger than the
6669** "sz" parameter to [SQLITE_CONFIG_SCRATCH]) and because no scratch buffer
6670** slots were available.
6671** </dd>)^
6672**
6673** [[SQLITE_STATUS_SCRATCH_SIZE]] ^(<dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
6674** <dd>This parameter records the largest memory allocation request
6675** handed to [scratch memory allocator]. Only the value returned in the
6676** *pHighwater parameter to [sqlite3_status()] is of interest.
6677** The value written into the *pCurrent parameter is undefined.</dd>)^
6678**
6679** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
6680** <dd>The *pHighwater parameter records the deepest parser stack.
6681** The *pCurrent value is undefined. The *pHighwater value is only
6682** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
6683** </dl>
6684**
6685** New status parameters may be added from time to time.
6686*/
6687#define SQLITE_STATUS_MEMORY_USED 0
6688#define SQLITE_STATUS_PAGECACHE_USED 1
6689#define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
6690#define SQLITE_STATUS_SCRATCH_USED 3
6691#define SQLITE_STATUS_SCRATCH_OVERFLOW 4
6692#define SQLITE_STATUS_MALLOC_SIZE 5
6693#define SQLITE_STATUS_PARSER_STACK 6
6694#define SQLITE_STATUS_PAGECACHE_SIZE 7
6695#define SQLITE_STATUS_SCRATCH_SIZE 8
6696#define SQLITE_STATUS_MALLOC_COUNT 9
6697
6698/*
6699** CAPI3REF: Database Connection Status
6700** METHOD: sqlite3
6701**
6702** ^This interface is used to retrieve runtime status information
6703** about a single [database connection]. ^The first argument is the
6704** database connection object to be interrogated. ^The second argument
6705** is an integer constant, taken from the set of
6706** [SQLITE_DBSTATUS options], that
6707** determines the parameter to interrogate. The set of
6708** [SQLITE_DBSTATUS options] is likely
6709** to grow in future releases of SQLite.
6710**
6711** ^The current value of the requested parameter is written into *pCur
6712** and the highest instantaneous value is written into *pHiwtr. ^If
6713** the resetFlg is true, then the highest instantaneous value is
6714** reset back down to the current value.
6715**
6716** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
6717** non-zero [error code] on failure.
6718**
6719** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
6720*/
6721SQLITE_API int SQLITE_STDCALL sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
6722
6723/*
6724** CAPI3REF: Status Parameters for database connections
6725** KEYWORDS: {SQLITE_DBSTATUS options}
6726**
6727** These constants are the available integer "verbs" that can be passed as
6728** the second argument to the [sqlite3_db_status()] interface.
6729**
6730** New verbs may be added in future releases of SQLite. Existing verbs
6731** might be discontinued. Applications should check the return code from
6732** [sqlite3_db_status()] to make sure that the call worked.
6733** The [sqlite3_db_status()] interface will return a non-zero error code
6734** if a discontinued or unsupported verb is invoked.
6735**
6736** <dl>
6737** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
6738** <dd>This parameter returns the number of lookaside memory slots currently
6739** checked out.</dd>)^
6740**
6741** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
6742** <dd>This parameter returns the number malloc attempts that were
6743** satisfied using lookaside memory. Only the high-water value is meaningful;
6744** the current value is always zero.)^
6745**
6746** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
6747** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
6748** <dd>This parameter returns the number malloc attempts that might have
6749** been satisfied using lookaside memory but failed due to the amount of
6750** memory requested being larger than the lookaside slot size.
6751** Only the high-water value is meaningful;
6752** the current value is always zero.)^
6753**
6754** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
6755** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
6756** <dd>This parameter returns the number malloc attempts that might have
6757** been satisfied using lookaside memory but failed due to all lookaside
6758** memory already being in use.
6759** Only the high-water value is meaningful;
6760** the current value is always zero.)^
6761**
6762** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
6763** <dd>This parameter returns the approximate number of bytes of heap
6764** memory used by all pager caches associated with the database connection.)^
6765** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
6766**
6767** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
6768** <dd>This parameter returns the approximate number of bytes of heap
6769** memory used to store the schema for all databases associated
6770** with the connection - main, temp, and any [ATTACH]-ed databases.)^
6771** ^The full amount of memory used by the schemas is reported, even if the
6772** schema memory is shared with other database connections due to
6773** [shared cache mode] being enabled.
6774** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
6775**
6776** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
6777** <dd>This parameter returns the approximate number of bytes of heap
6778** and lookaside memory used by all prepared statements associated with
6779** the database connection.)^
6780** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
6781** </dd>
6782**
6783** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
6784** <dd>This parameter returns the number of pager cache hits that have
6785** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
6786** is always 0.
6787** </dd>
6788**
6789** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
6790** <dd>This parameter returns the number of pager cache misses that have
6791** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
6792** is always 0.
6793** </dd>
6794**
6795** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
6796** <dd>This parameter returns the number of dirty cache entries that have
6797** been written to disk. Specifically, the number of pages written to the
6798** wal file in wal mode databases, or the number of pages written to the
6799** database file in rollback mode databases. Any pages written as part of
6800** transaction rollback or database recovery operations are not included.
6801** If an IO or other error occurs while writing a page to disk, the effect
6802** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
6803** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
6804** </dd>
6805**
6806** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
6807** <dd>This parameter returns zero for the current value if and only if
6808** all foreign key constraints (deferred or immediate) have been
6809** resolved.)^ ^The highwater mark is always 0.
6810** </dd>
6811** </dl>
6812*/
6813#define SQLITE_DBSTATUS_LOOKASIDE_USED 0
6814#define SQLITE_DBSTATUS_CACHE_USED 1
6815#define SQLITE_DBSTATUS_SCHEMA_USED 2
6816#define SQLITE_DBSTATUS_STMT_USED 3
6817#define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
6818#define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
6819#define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
6820#define SQLITE_DBSTATUS_CACHE_HIT 7
6821#define SQLITE_DBSTATUS_CACHE_MISS 8
6822#define SQLITE_DBSTATUS_CACHE_WRITE 9
6823#define SQLITE_DBSTATUS_DEFERRED_FKS 10
6824#define SQLITE_DBSTATUS_MAX 10 /* Largest defined DBSTATUS */
6825
6826
6827/*
6828** CAPI3REF: Prepared Statement Status
6829** METHOD: sqlite3_stmt
6830**
6831** ^(Each prepared statement maintains various
6832** [SQLITE_STMTSTATUS counters] that measure the number
6833** of times it has performed specific operations.)^ These counters can
6834** be used to monitor the performance characteristics of the prepared
6835** statements. For example, if the number of table steps greatly exceeds
6836** the number of table searches or result rows, that would tend to indicate
6837** that the prepared statement is using a full table scan rather than
6838** an index.
6839**
6840** ^(This interface is used to retrieve and reset counter values from
6841** a [prepared statement]. The first argument is the prepared statement
6842** object to be interrogated. The second argument
6843** is an integer code for a specific [SQLITE_STMTSTATUS counter]
6844** to be interrogated.)^
6845** ^The current value of the requested counter is returned.
6846** ^If the resetFlg is true, then the counter is reset to zero after this
6847** interface call returns.
6848**
6849** See also: [sqlite3_status()] and [sqlite3_db_status()].
6850*/
6851SQLITE_API int SQLITE_STDCALL sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
6852
6853/*
6854** CAPI3REF: Status Parameters for prepared statements
6855** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
6856**
6857** These preprocessor macros define integer codes that name counter
6858** values associated with the [sqlite3_stmt_status()] interface.
6859** The meanings of the various counters are as follows:
6860**
6861** <dl>
6862** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
6863** <dd>^This is the number of times that SQLite has stepped forward in
6864** a table as part of a full table scan. Large numbers for this counter
6865** may indicate opportunities for performance improvement through
6866** careful use of indices.</dd>
6867**
6868** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
6869** <dd>^This is the number of sort operations that have occurred.
6870** A non-zero value in this counter may indicate an opportunity to
6871** improvement performance through careful use of indices.</dd>
6872**
6873** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
6874** <dd>^This is the number of rows inserted into transient indices that
6875** were created automatically in order to help joins run faster.
6876** A non-zero value in this counter may indicate an opportunity to
6877** improvement performance by adding permanent indices that do not
6878** need to be reinitialized each time the statement is run.</dd>
6879**
6880** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
6881** <dd>^This is the number of virtual machine operations executed
6882** by the prepared statement if that number is less than or equal
6883** to 2147483647. The number of virtual machine operations can be
6884** used as a proxy for the total work done by the prepared statement.
6885** If the number of virtual machine operations exceeds 2147483647
6886** then the value returned by this statement status code is undefined.
6887** </dd>
6888** </dl>
6889*/
6890#define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
6891#define SQLITE_STMTSTATUS_SORT 2
6892#define SQLITE_STMTSTATUS_AUTOINDEX 3
6893#define SQLITE_STMTSTATUS_VM_STEP 4
6894
6895/*
6896** CAPI3REF: Custom Page Cache Object
6897**
6898** The sqlite3_pcache type is opaque. It is implemented by
6899** the pluggable module. The SQLite core has no knowledge of
6900** its size or internal structure and never deals with the
6901** sqlite3_pcache object except by holding and passing pointers
6902** to the object.
6903**
6904** See [sqlite3_pcache_methods2] for additional information.
6905*/
6906typedef struct sqlite3_pcache sqlite3_pcache;
6907
6908/*
6909** CAPI3REF: Custom Page Cache Object
6910**
6911** The sqlite3_pcache_page object represents a single page in the
6912** page cache. The page cache will allocate instances of this
6913** object. Various methods of the page cache use pointers to instances
6914** of this object as parameters or as their return value.
6915**
6916** See [sqlite3_pcache_methods2] for additional information.
6917*/
6918typedef struct sqlite3_pcache_page sqlite3_pcache_page;
6919struct sqlite3_pcache_page {
6920 void *pBuf; /* The content of the page */
6921 void *pExtra; /* Extra information associated with the page */
6922};
6923
6924/*
6925** CAPI3REF: Application Defined Page Cache.
6926** KEYWORDS: {page cache}
6927**
6928** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
6929** register an alternative page cache implementation by passing in an
6930** instance of the sqlite3_pcache_methods2 structure.)^
6931** In many applications, most of the heap memory allocated by
6932** SQLite is used for the page cache.
6933** By implementing a
6934** custom page cache using this API, an application can better control
6935** the amount of memory consumed by SQLite, the way in which
6936** that memory is allocated and released, and the policies used to
6937** determine exactly which parts of a database file are cached and for
6938** how long.
6939**
6940** The alternative page cache mechanism is an
6941** extreme measure that is only needed by the most demanding applications.
6942** The built-in page cache is recommended for most uses.
6943**
6944** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
6945** internal buffer by SQLite within the call to [sqlite3_config]. Hence
6946** the application may discard the parameter after the call to
6947** [sqlite3_config()] returns.)^
6948**
6949** [[the xInit() page cache method]]
6950** ^(The xInit() method is called once for each effective
6951** call to [sqlite3_initialize()])^
6952** (usually only once during the lifetime of the process). ^(The xInit()
6953** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
6954** The intent of the xInit() method is to set up global data structures
6955** required by the custom page cache implementation.
6956** ^(If the xInit() method is NULL, then the
6957** built-in default page cache is used instead of the application defined
6958** page cache.)^
6959**
6960** [[the xShutdown() page cache method]]
6961** ^The xShutdown() method is called by [sqlite3_shutdown()].
6962** It can be used to clean up
6963** any outstanding resources before process shutdown, if required.
6964** ^The xShutdown() method may be NULL.
6965**
6966** ^SQLite automatically serializes calls to the xInit method,
6967** so the xInit method need not be threadsafe. ^The
6968** xShutdown method is only called from [sqlite3_shutdown()] so it does
6969** not need to be threadsafe either. All other methods must be threadsafe
6970** in multithreaded applications.
6971**
6972** ^SQLite will never invoke xInit() more than once without an intervening
6973** call to xShutdown().
6974**
6975** [[the xCreate() page cache methods]]
6976** ^SQLite invokes the xCreate() method to construct a new cache instance.
6977** SQLite will typically create one cache instance for each open database file,
6978** though this is not guaranteed. ^The
6979** first parameter, szPage, is the size in bytes of the pages that must
6980** be allocated by the cache. ^szPage will always a power of two. ^The
6981** second parameter szExtra is a number of bytes of extra storage
6982** associated with each page cache entry. ^The szExtra parameter will
6983** a number less than 250. SQLite will use the
6984** extra szExtra bytes on each page to store metadata about the underlying
6985** database page on disk. The value passed into szExtra depends
6986** on the SQLite version, the target platform, and how SQLite was compiled.
6987** ^The third argument to xCreate(), bPurgeable, is true if the cache being
6988** created will be used to cache database pages of a file stored on disk, or
6989** false if it is used for an in-memory database. The cache implementation
6990** does not have to do anything special based with the value of bPurgeable;
6991** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
6992** never invoke xUnpin() except to deliberately delete a page.
6993** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
6994** false will always have the "discard" flag set to true.
6995** ^Hence, a cache created with bPurgeable false will
6996** never contain any unpinned pages.
6997**
6998** [[the xCachesize() page cache method]]
6999** ^(The xCachesize() method may be called at any time by SQLite to set the
7000** suggested maximum cache-size (number of pages stored by) the cache
7001** instance passed as the first argument. This is the value configured using
7002** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
7003** parameter, the implementation is not required to do anything with this
7004** value; it is advisory only.
7005**
7006** [[the xPagecount() page cache methods]]
7007** The xPagecount() method must return the number of pages currently
7008** stored in the cache, both pinned and unpinned.
7009**
7010** [[the xFetch() page cache methods]]
7011** The xFetch() method locates a page in the cache and returns a pointer to
7012** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
7013** The pBuf element of the returned sqlite3_pcache_page object will be a
7014** pointer to a buffer of szPage bytes used to store the content of a
7015** single database page. The pExtra element of sqlite3_pcache_page will be
7016** a pointer to the szExtra bytes of extra storage that SQLite has requested
7017** for each entry in the page cache.
7018**
7019** The page to be fetched is determined by the key. ^The minimum key value
7020** is 1. After it has been retrieved using xFetch, the page is considered
7021** to be "pinned".
7022**
7023** If the requested page is already in the page cache, then the page cache
7024** implementation must return a pointer to the page buffer with its content
7025** intact. If the requested page is not already in the cache, then the
7026** cache implementation should use the value of the createFlag
7027** parameter to help it determined what action to take:
7028**
7029** <table border=1 width=85% align=center>
7030** <tr><th> createFlag <th> Behavior when page is not already in cache
7031** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
7032** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
7033** Otherwise return NULL.
7034** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
7035** NULL if allocating a new page is effectively impossible.
7036** </table>
7037**
7038** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
7039** will only use a createFlag of 2 after a prior call with a createFlag of 1
7040** failed.)^ In between the to xFetch() calls, SQLite may
7041** attempt to unpin one or more cache pages by spilling the content of
7042** pinned pages to disk and synching the operating system disk cache.
7043**
7044** [[the xUnpin() page cache method]]
7045** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
7046** as its second argument. If the third parameter, discard, is non-zero,
7047** then the page must be evicted from the cache.
7048** ^If the discard parameter is
7049** zero, then the page may be discarded or retained at the discretion of
7050** page cache implementation. ^The page cache implementation
7051** may choose to evict unpinned pages at any time.
7052**
7053** The cache must not perform any reference counting. A single
7054** call to xUnpin() unpins the page regardless of the number of prior calls
7055** to xFetch().
7056**
7057** [[the xRekey() page cache methods]]
7058** The xRekey() method is used to change the key value associated with the
7059** page passed as the second argument. If the cache
7060** previously contains an entry associated with newKey, it must be
7061** discarded. ^Any prior cache entry associated with newKey is guaranteed not
7062** to be pinned.
7063**
7064** When SQLite calls the xTruncate() method, the cache must discard all
7065** existing cache entries with page numbers (keys) greater than or equal
7066** to the value of the iLimit parameter passed to xTruncate(). If any
7067** of these pages are pinned, they are implicitly unpinned, meaning that
7068** they can be safely discarded.
7069**
7070** [[the xDestroy() page cache method]]
7071** ^The xDestroy() method is used to delete a cache allocated by xCreate().
7072** All resources associated with the specified cache should be freed. ^After
7073** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
7074** handle invalid, and will not use it with any other sqlite3_pcache_methods2
7075** functions.
7076**
7077** [[the xShrink() page cache method]]
7078** ^SQLite invokes the xShrink() method when it wants the page cache to
7079** free up as much of heap memory as possible. The page cache implementation
7080** is not obligated to free any memory, but well-behaved implementations should
7081** do their best.
7082*/
7083typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
7084struct sqlite3_pcache_methods2 {
7085 int iVersion;
7086 void *pArg;
7087 int (*xInit)(void*);
7088 void (*xShutdown)(void*);
7089 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
7090 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7091 int (*xPagecount)(sqlite3_pcache*);
7092 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7093 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
7094 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
7095 unsigned oldKey, unsigned newKey);
7096 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7097 void (*xDestroy)(sqlite3_pcache*);
7098 void (*xShrink)(sqlite3_pcache*);
7099};
7100
7101/*
7102** This is the obsolete pcache_methods object that has now been replaced
7103** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
7104** retained in the header file for backwards compatibility only.
7105*/
7106typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
7107struct sqlite3_pcache_methods {
7108 void *pArg;
7109 int (*xInit)(void*);
7110 void (*xShutdown)(void*);
7111 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
7112 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
7113 int (*xPagecount)(sqlite3_pcache*);
7114 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
7115 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
7116 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
7117 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
7118 void (*xDestroy)(sqlite3_pcache*);
7119};
7120
7121
7122/*
7123** CAPI3REF: Online Backup Object
7124**
7125** The sqlite3_backup object records state information about an ongoing
7126** online backup operation. ^The sqlite3_backup object is created by
7127** a call to [sqlite3_backup_init()] and is destroyed by a call to
7128** [sqlite3_backup_finish()].
7129**
7130** See Also: [Using the SQLite Online Backup API]
7131*/
7132typedef struct sqlite3_backup sqlite3_backup;
7133
7134/*
7135** CAPI3REF: Online Backup API.
7136**
7137** The backup API copies the content of one database into another.
7138** It is useful either for creating backups of databases or
7139** for copying in-memory databases to or from persistent files.
7140**
7141** See Also: [Using the SQLite Online Backup API]
7142**
7143** ^SQLite holds a write transaction open on the destination database file
7144** for the duration of the backup operation.
7145** ^The source database is read-locked only while it is being read;
7146** it is not locked continuously for the entire backup operation.
7147** ^Thus, the backup may be performed on a live source database without
7148** preventing other database connections from
7149** reading or writing to the source database while the backup is underway.
7150**
7151** ^(To perform a backup operation:
7152** <ol>
7153** <li><b>sqlite3_backup_init()</b> is called once to initialize the
7154** backup,
7155** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
7156** the data between the two databases, and finally
7157** <li><b>sqlite3_backup_finish()</b> is called to release all resources
7158** associated with the backup operation.
7159** </ol>)^
7160** There should be exactly one call to sqlite3_backup_finish() for each
7161** successful call to sqlite3_backup_init().
7162**
7163** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
7164**
7165** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
7166** [database connection] associated with the destination database
7167** and the database name, respectively.
7168** ^The database name is "main" for the main database, "temp" for the
7169** temporary database, or the name specified after the AS keyword in
7170** an [ATTACH] statement for an attached database.
7171** ^The S and M arguments passed to
7172** sqlite3_backup_init(D,N,S,M) identify the [database connection]
7173** and database name of the source database, respectively.
7174** ^The source and destination [database connections] (parameters S and D)
7175** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
7176** an error.
7177**
7178** ^A call to sqlite3_backup_init() will fail, returning NULL, if
7179** there is already a read or read-write transaction open on the
7180** destination database.
7181**
7182** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
7183** returned and an error code and error message are stored in the
7184** destination [database connection] D.
7185** ^The error code and message for the failed call to sqlite3_backup_init()
7186** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
7187** [sqlite3_errmsg16()] functions.
7188** ^A successful call to sqlite3_backup_init() returns a pointer to an
7189** [sqlite3_backup] object.
7190** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
7191** sqlite3_backup_finish() functions to perform the specified backup
7192** operation.
7193**
7194** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
7195**
7196** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
7197** the source and destination databases specified by [sqlite3_backup] object B.
7198** ^If N is negative, all remaining source pages are copied.
7199** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
7200** are still more pages to be copied, then the function returns [SQLITE_OK].
7201** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
7202** from source to destination, then it returns [SQLITE_DONE].
7203** ^If an error occurs while running sqlite3_backup_step(B,N),
7204** then an [error code] is returned. ^As well as [SQLITE_OK] and
7205** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
7206** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
7207** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
7208**
7209** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
7210** <ol>
7211** <li> the destination database was opened read-only, or
7212** <li> the destination database is using write-ahead-log journaling
7213** and the destination and source page sizes differ, or
7214** <li> the destination database is an in-memory database and the
7215** destination and source page sizes differ.
7216** </ol>)^
7217**
7218** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
7219** the [sqlite3_busy_handler | busy-handler function]
7220** is invoked (if one is specified). ^If the
7221** busy-handler returns non-zero before the lock is available, then
7222** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
7223** sqlite3_backup_step() can be retried later. ^If the source
7224** [database connection]
7225** is being used to write to the source database when sqlite3_backup_step()
7226** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
7227** case the call to sqlite3_backup_step() can be retried later on. ^(If
7228** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
7229** [SQLITE_READONLY] is returned, then
7230** there is no point in retrying the call to sqlite3_backup_step(). These
7231** errors are considered fatal.)^ The application must accept
7232** that the backup operation has failed and pass the backup operation handle
7233** to the sqlite3_backup_finish() to release associated resources.
7234**
7235** ^The first call to sqlite3_backup_step() obtains an exclusive lock
7236** on the destination file. ^The exclusive lock is not released until either
7237** sqlite3_backup_finish() is called or the backup operation is complete
7238** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
7239** sqlite3_backup_step() obtains a [shared lock] on the source database that
7240** lasts for the duration of the sqlite3_backup_step() call.
7241** ^Because the source database is not locked between calls to
7242** sqlite3_backup_step(), the source database may be modified mid-way
7243** through the backup process. ^If the source database is modified by an
7244** external process or via a database connection other than the one being
7245** used by the backup operation, then the backup will be automatically
7246** restarted by the next call to sqlite3_backup_step(). ^If the source
7247** database is modified by the using the same database connection as is used
7248** by the backup operation, then the backup database is automatically
7249** updated at the same time.
7250**
7251** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
7252**
7253** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
7254** application wishes to abandon the backup operation, the application
7255** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
7256** ^The sqlite3_backup_finish() interfaces releases all
7257** resources associated with the [sqlite3_backup] object.
7258** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
7259** active write-transaction on the destination database is rolled back.
7260** The [sqlite3_backup] object is invalid
7261** and may not be used following a call to sqlite3_backup_finish().
7262**
7263** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
7264** sqlite3_backup_step() errors occurred, regardless or whether or not
7265** sqlite3_backup_step() completed.
7266** ^If an out-of-memory condition or IO error occurred during any prior
7267** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
7268** sqlite3_backup_finish() returns the corresponding [error code].
7269**
7270** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
7271** is not a permanent error and does not affect the return value of
7272** sqlite3_backup_finish().
7273**
7274** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
7275** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
7276**
7277** ^The sqlite3_backup_remaining() routine returns the number of pages still
7278** to be backed up at the conclusion of the most recent sqlite3_backup_step().
7279** ^The sqlite3_backup_pagecount() routine returns the total number of pages
7280** in the source database at the conclusion of the most recent
7281** sqlite3_backup_step().
7282** ^(The values returned by these functions are only updated by
7283** sqlite3_backup_step(). If the source database is modified in a way that
7284** changes the size of the source database or the number of pages remaining,
7285** those changes are not reflected in the output of sqlite3_backup_pagecount()
7286** and sqlite3_backup_remaining() until after the next
7287** sqlite3_backup_step().)^
7288**
7289** <b>Concurrent Usage of Database Handles</b>
7290**
7291** ^The source [database connection] may be used by the application for other
7292** purposes while a backup operation is underway or being initialized.
7293** ^If SQLite is compiled and configured to support threadsafe database
7294** connections, then the source database connection may be used concurrently
7295** from within other threads.
7296**
7297** However, the application must guarantee that the destination
7298** [database connection] is not passed to any other API (by any thread) after
7299** sqlite3_backup_init() is called and before the corresponding call to
7300** sqlite3_backup_finish(). SQLite does not currently check to see
7301** if the application incorrectly accesses the destination [database connection]
7302** and so no error code is reported, but the operations may malfunction
7303** nevertheless. Use of the destination database connection while a
7304** backup is in progress might also also cause a mutex deadlock.
7305**
7306** If running in [shared cache mode], the application must
7307** guarantee that the shared cache used by the destination database
7308** is not accessed while the backup is running. In practice this means
7309** that the application must guarantee that the disk file being
7310** backed up to is not accessed by any connection within the process,
7311** not just the specific connection that was passed to sqlite3_backup_init().
7312**
7313** The [sqlite3_backup] object itself is partially threadsafe. Multiple
7314** threads may safely make multiple concurrent calls to sqlite3_backup_step().
7315** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
7316** APIs are not strictly speaking threadsafe. If they are invoked at the
7317** same time as another thread is invoking sqlite3_backup_step() it is
7318** possible that they return invalid values.
7319*/
7320SQLITE_API sqlite3_backup *SQLITE_STDCALL sqlite3_backup_init(
7321 sqlite3 *pDest, /* Destination database handle */
7322 const char *zDestName, /* Destination database name */
7323 sqlite3 *pSource, /* Source database handle */
7324 const char *zSourceName /* Source database name */
7325);
7326SQLITE_API int SQLITE_STDCALL sqlite3_backup_step(sqlite3_backup *p, int nPage);
7327SQLITE_API int SQLITE_STDCALL sqlite3_backup_finish(sqlite3_backup *p);
7328SQLITE_API int SQLITE_STDCALL sqlite3_backup_remaining(sqlite3_backup *p);
7329SQLITE_API int SQLITE_STDCALL sqlite3_backup_pagecount(sqlite3_backup *p);
7330
7331/*
7332** CAPI3REF: Unlock Notification
7333** METHOD: sqlite3
7334**
7335** ^When running in shared-cache mode, a database operation may fail with
7336** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
7337** individual tables within the shared-cache cannot be obtained. See
7338** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
7339** ^This API may be used to register a callback that SQLite will invoke
7340** when the connection currently holding the required lock relinquishes it.
7341** ^This API is only available if the library was compiled with the
7342** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
7343**
7344** See Also: [Using the SQLite Unlock Notification Feature].
7345**
7346** ^Shared-cache locks are released when a database connection concludes
7347** its current transaction, either by committing it or rolling it back.
7348**
7349** ^When a connection (known as the blocked connection) fails to obtain a
7350** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
7351** identity of the database connection (the blocking connection) that
7352** has locked the required resource is stored internally. ^After an
7353** application receives an SQLITE_LOCKED error, it may call the
7354** sqlite3_unlock_notify() method with the blocked connection handle as
7355** the first argument to register for a callback that will be invoked
7356** when the blocking connections current transaction is concluded. ^The
7357** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
7358** call that concludes the blocking connections transaction.
7359**
7360** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
7361** there is a chance that the blocking connection will have already
7362** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
7363** If this happens, then the specified callback is invoked immediately,
7364** from within the call to sqlite3_unlock_notify().)^
7365**
7366** ^If the blocked connection is attempting to obtain a write-lock on a
7367** shared-cache table, and more than one other connection currently holds
7368** a read-lock on the same table, then SQLite arbitrarily selects one of
7369** the other connections to use as the blocking connection.
7370**
7371** ^(There may be at most one unlock-notify callback registered by a
7372** blocked connection. If sqlite3_unlock_notify() is called when the
7373** blocked connection already has a registered unlock-notify callback,
7374** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
7375** called with a NULL pointer as its second argument, then any existing
7376** unlock-notify callback is canceled. ^The blocked connections
7377** unlock-notify callback may also be canceled by closing the blocked
7378** connection using [sqlite3_close()].
7379**
7380** The unlock-notify callback is not reentrant. If an application invokes
7381** any sqlite3_xxx API functions from within an unlock-notify callback, a
7382** crash or deadlock may be the result.
7383**
7384** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
7385** returns SQLITE_OK.
7386**
7387** <b>Callback Invocation Details</b>
7388**
7389** When an unlock-notify callback is registered, the application provides a
7390** single void* pointer that is passed to the callback when it is invoked.
7391** However, the signature of the callback function allows SQLite to pass
7392** it an array of void* context pointers. The first argument passed to
7393** an unlock-notify callback is a pointer to an array of void* pointers,
7394** and the second is the number of entries in the array.
7395**
7396** When a blocking connections transaction is concluded, there may be
7397** more than one blocked connection that has registered for an unlock-notify
7398** callback. ^If two or more such blocked connections have specified the
7399** same callback function, then instead of invoking the callback function
7400** multiple times, it is invoked once with the set of void* context pointers
7401** specified by the blocked connections bundled together into an array.
7402** This gives the application an opportunity to prioritize any actions
7403** related to the set of unblocked database connections.
7404**
7405** <b>Deadlock Detection</b>
7406**
7407** Assuming that after registering for an unlock-notify callback a
7408** database waits for the callback to be issued before taking any further
7409** action (a reasonable assumption), then using this API may cause the
7410** application to deadlock. For example, if connection X is waiting for
7411** connection Y's transaction to be concluded, and similarly connection
7412** Y is waiting on connection X's transaction, then neither connection
7413** will proceed and the system may remain deadlocked indefinitely.
7414**
7415** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
7416** detection. ^If a given call to sqlite3_unlock_notify() would put the
7417** system in a deadlocked state, then SQLITE_LOCKED is returned and no
7418** unlock-notify callback is registered. The system is said to be in
7419** a deadlocked state if connection A has registered for an unlock-notify
7420** callback on the conclusion of connection B's transaction, and connection
7421** B has itself registered for an unlock-notify callback when connection
7422** A's transaction is concluded. ^Indirect deadlock is also detected, so
7423** the system is also considered to be deadlocked if connection B has
7424** registered for an unlock-notify callback on the conclusion of connection
7425** C's transaction, where connection C is waiting on connection A. ^Any
7426** number of levels of indirection are allowed.
7427**
7428** <b>The "DROP TABLE" Exception</b>
7429**
7430** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
7431** always appropriate to call sqlite3_unlock_notify(). There is however,
7432** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
7433** SQLite checks if there are any currently executing SELECT statements
7434** that belong to the same connection. If there are, SQLITE_LOCKED is
7435** returned. In this case there is no "blocking connection", so invoking
7436** sqlite3_unlock_notify() results in the unlock-notify callback being
7437** invoked immediately. If the application then re-attempts the "DROP TABLE"
7438** or "DROP INDEX" query, an infinite loop might be the result.
7439**
7440** One way around this problem is to check the extended error code returned
7441** by an sqlite3_step() call. ^(If there is a blocking connection, then the
7442** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
7443** the special "DROP TABLE/INDEX" case, the extended error code is just
7444** SQLITE_LOCKED.)^
7445*/
7446SQLITE_API int SQLITE_STDCALL sqlite3_unlock_notify(
7447 sqlite3 *pBlocked, /* Waiting connection */
7448 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
7449 void *pNotifyArg /* Argument to pass to xNotify */
7450);
7451
7452
7453/*
7454** CAPI3REF: String Comparison
7455**
7456** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
7457** and extensions to compare the contents of two buffers containing UTF-8
7458** strings in a case-independent fashion, using the same definition of "case
7459** independence" that SQLite uses internally when comparing identifiers.
7460*/
7461SQLITE_API int SQLITE_STDCALL sqlite3_stricmp(const char *, const char *);
7462SQLITE_API int SQLITE_STDCALL sqlite3_strnicmp(const char *, const char *, int);
7463
7464/*
7465** CAPI3REF: String Globbing
7466*
7467** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
7468** string X matches the [GLOB] pattern P.
7469** ^The definition of [GLOB] pattern matching used in
7470** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
7471** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
7472** is case sensitive.
7473**
7474** Note that this routine returns zero on a match and non-zero if the strings
7475** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
7476**
7477** See also: [sqlite3_strlike()].
7478*/
7479SQLITE_API int SQLITE_STDCALL sqlite3_strglob(const char *zGlob, const char *zStr);
7480
7481/*
7482** CAPI3REF: String LIKE Matching
7483*
7484** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
7485** string X matches the [LIKE] pattern P with escape character E.
7486** ^The definition of [LIKE] pattern matching used in
7487** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
7488** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
7489** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
7490** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
7491** insensitive - equivalent upper and lower case ASCII characters match
7492** one another.
7493**
7494** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
7495** only ASCII characters are case folded.
7496**
7497** Note that this routine returns zero on a match and non-zero if the strings
7498** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
7499**
7500** See also: [sqlite3_strglob()].
7501*/
7502SQLITE_API int SQLITE_STDCALL sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
7503
7504/*
7505** CAPI3REF: Error Logging Interface
7506**
7507** ^The [sqlite3_log()] interface writes a message into the [error log]
7508** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
7509** ^If logging is enabled, the zFormat string and subsequent arguments are
7510** used with [sqlite3_snprintf()] to generate the final output string.
7511**
7512** The sqlite3_log() interface is intended for use by extensions such as
7513** virtual tables, collating functions, and SQL functions. While there is
7514** nothing to prevent an application from calling sqlite3_log(), doing so
7515** is considered bad form.
7516**
7517** The zFormat string must not be NULL.
7518**
7519** To avoid deadlocks and other threading problems, the sqlite3_log() routine
7520** will not use dynamically allocated memory. The log message is stored in
7521** a fixed-length buffer on the stack. If the log message is longer than
7522** a few hundred characters, it will be truncated to the length of the
7523** buffer.
7524*/
7525SQLITE_API void SQLITE_CDECL sqlite3_log(int iErrCode, const char *zFormat, ...);
7526
7527/*
7528** CAPI3REF: Write-Ahead Log Commit Hook
7529** METHOD: sqlite3
7530**
7531** ^The [sqlite3_wal_hook()] function is used to register a callback that
7532** is invoked each time data is committed to a database in wal mode.
7533**
7534** ^(The callback is invoked by SQLite after the commit has taken place and
7535** the associated write-lock on the database released)^, so the implementation
7536** may read, write or [checkpoint] the database as required.
7537**
7538** ^The first parameter passed to the callback function when it is invoked
7539** is a copy of the third parameter passed to sqlite3_wal_hook() when
7540** registering the callback. ^The second is a copy of the database handle.
7541** ^The third parameter is the name of the database that was written to -
7542** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
7543** is the number of pages currently in the write-ahead log file,
7544** including those that were just committed.
7545**
7546** The callback function should normally return [SQLITE_OK]. ^If an error
7547** code is returned, that error will propagate back up through the
7548** SQLite code base to cause the statement that provoked the callback
7549** to report an error, though the commit will have still occurred. If the
7550** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
7551** that does not correspond to any valid SQLite error code, the results
7552** are undefined.
7553**
7554** A single database handle may have at most a single write-ahead log callback
7555** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
7556** previously registered write-ahead log callback. ^Note that the
7557** [sqlite3_wal_autocheckpoint()] interface and the
7558** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
7559** overwrite any prior [sqlite3_wal_hook()] settings.
7560*/
7561SQLITE_API void *SQLITE_STDCALL sqlite3_wal_hook(
7562 sqlite3*,
7563 int(*)(void *,sqlite3*,const char*,int),
7564 void*
7565);
7566
7567/*
7568** CAPI3REF: Configure an auto-checkpoint
7569** METHOD: sqlite3
7570**
7571** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
7572** [sqlite3_wal_hook()] that causes any database on [database connection] D
7573** to automatically [checkpoint]
7574** after committing a transaction if there are N or
7575** more frames in the [write-ahead log] file. ^Passing zero or
7576** a negative value as the nFrame parameter disables automatic
7577** checkpoints entirely.
7578**
7579** ^The callback registered by this function replaces any existing callback
7580** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
7581** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
7582** configured by this function.
7583**
7584** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
7585** from SQL.
7586**
7587** ^Checkpoints initiated by this mechanism are
7588** [sqlite3_wal_checkpoint_v2|PASSIVE].
7589**
7590** ^Every new [database connection] defaults to having the auto-checkpoint
7591** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
7592** pages. The use of this interface
7593** is only necessary if the default setting is found to be suboptimal
7594** for a particular application.
7595*/
7596SQLITE_API int SQLITE_STDCALL sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
7597
7598/*
7599** CAPI3REF: Checkpoint a database
7600** METHOD: sqlite3
7601**
7602** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
7603** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
7604**
7605** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
7606** [write-ahead log] for database X on [database connection] D to be
7607** transferred into the database file and for the write-ahead log to
7608** be reset. See the [checkpointing] documentation for addition
7609** information.
7610**
7611** This interface used to be the only way to cause a checkpoint to
7612** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
7613** interface was added. This interface is retained for backwards
7614** compatibility and as a convenience for applications that need to manually
7615** start a callback but which do not need the full power (and corresponding
7616** complication) of [sqlite3_wal_checkpoint_v2()].
7617*/
7618SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
7619
7620/*
7621** CAPI3REF: Checkpoint a database
7622** METHOD: sqlite3
7623**
7624** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
7625** operation on database X of [database connection] D in mode M. Status
7626** information is written back into integers pointed to by L and C.)^
7627** ^(The M parameter must be a valid [checkpoint mode]:)^
7628**
7629** <dl>
7630** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
7631** ^Checkpoint as many frames as possible without waiting for any database
7632** readers or writers to finish, then sync the database file if all frames
7633** in the log were checkpointed. ^The [busy-handler callback]
7634** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
7635** ^On the other hand, passive mode might leave the checkpoint unfinished
7636** if there are concurrent readers or writers.
7637**
7638** <dt>SQLITE_CHECKPOINT_FULL<dd>
7639** ^This mode blocks (it invokes the
7640** [sqlite3_busy_handler|busy-handler callback]) until there is no
7641** database writer and all readers are reading from the most recent database
7642** snapshot. ^It then checkpoints all frames in the log file and syncs the
7643** database file. ^This mode blocks new database writers while it is pending,
7644** but new database readers are allowed to continue unimpeded.
7645**
7646** <dt>SQLITE_CHECKPOINT_RESTART<dd>
7647** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
7648** that after checkpointing the log file it blocks (calls the
7649** [busy-handler callback])
7650** until all readers are reading from the database file only. ^This ensures
7651** that the next writer will restart the log file from the beginning.
7652** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
7653** database writer attempts while it is pending, but does not impede readers.
7654**
7655** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
7656** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
7657** addition that it also truncates the log file to zero bytes just prior
7658** to a successful return.
7659** </dl>
7660**
7661** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
7662** the log file or to -1 if the checkpoint could not run because
7663** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
7664** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
7665** log file (including any that were already checkpointed before the function
7666** was called) or to -1 if the checkpoint could not run due to an error or
7667** because the database is not in WAL mode. ^Note that upon successful
7668** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
7669** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
7670**
7671** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
7672** any other process is running a checkpoint operation at the same time, the
7673** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
7674** busy-handler configured, it will not be invoked in this case.
7675**
7676** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
7677** exclusive "writer" lock on the database file. ^If the writer lock cannot be
7678** obtained immediately, and a busy-handler is configured, it is invoked and
7679** the writer lock retried until either the busy-handler returns 0 or the lock
7680** is successfully obtained. ^The busy-handler is also invoked while waiting for
7681** database readers as described above. ^If the busy-handler returns 0 before
7682** the writer lock is obtained or while waiting for database readers, the
7683** checkpoint operation proceeds from that point in the same way as
7684** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
7685** without blocking any further. ^SQLITE_BUSY is returned in this case.
7686**
7687** ^If parameter zDb is NULL or points to a zero length string, then the
7688** specified operation is attempted on all WAL databases [attached] to
7689** [database connection] db. In this case the
7690** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
7691** an SQLITE_BUSY error is encountered when processing one or more of the
7692** attached WAL databases, the operation is still attempted on any remaining
7693** attached databases and SQLITE_BUSY is returned at the end. ^If any other
7694** error occurs while processing an attached database, processing is abandoned
7695** and the error code is returned to the caller immediately. ^If no error
7696** (SQLITE_BUSY or otherwise) is encountered while processing the attached
7697** databases, SQLITE_OK is returned.
7698**
7699** ^If database zDb is the name of an attached database that is not in WAL
7700** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
7701** zDb is not NULL (or a zero length string) and is not the name of any
7702** attached database, SQLITE_ERROR is returned to the caller.
7703**
7704** ^Unless it returns SQLITE_MISUSE,
7705** the sqlite3_wal_checkpoint_v2() interface
7706** sets the error information that is queried by
7707** [sqlite3_errcode()] and [sqlite3_errmsg()].
7708**
7709** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
7710** from SQL.
7711*/
7712SQLITE_API int SQLITE_STDCALL sqlite3_wal_checkpoint_v2(
7713 sqlite3 *db, /* Database handle */
7714 const char *zDb, /* Name of attached database (or NULL) */
7715 int eMode, /* SQLITE_CHECKPOINT_* value */
7716 int *pnLog, /* OUT: Size of WAL log in frames */
7717 int *pnCkpt /* OUT: Total number of frames checkpointed */
7718);
7719
7720/*
7721** CAPI3REF: Checkpoint Mode Values
7722** KEYWORDS: {checkpoint mode}
7723**
7724** These constants define all valid values for the "checkpoint mode" passed
7725** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
7726** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
7727** meaning of each of these checkpoint modes.
7728*/
7729#define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
7730#define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
7731#define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for for readers */
7732#define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
7733
7734/*
7735** CAPI3REF: Virtual Table Interface Configuration
7736**
7737** This function may be called by either the [xConnect] or [xCreate] method
7738** of a [virtual table] implementation to configure
7739** various facets of the virtual table interface.
7740**
7741** If this interface is invoked outside the context of an xConnect or
7742** xCreate virtual table method then the behavior is undefined.
7743**
7744** At present, there is only one option that may be configured using
7745** this function. (See [SQLITE_VTAB_CONSTRAINT_SUPPORT].) Further options
7746** may be added in the future.
7747*/
7748SQLITE_API int SQLITE_CDECL sqlite3_vtab_config(sqlite3*, int op, ...);
7749
7750/*
7751** CAPI3REF: Virtual Table Configuration Options
7752**
7753** These macros define the various options to the
7754** [sqlite3_vtab_config()] interface that [virtual table] implementations
7755** can use to customize and optimize their behavior.
7756**
7757** <dl>
7758** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT
7759** <dd>Calls of the form
7760** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
7761** where X is an integer. If X is zero, then the [virtual table] whose
7762** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
7763** support constraints. In this configuration (which is the default) if
7764** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
7765** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
7766** specified as part of the users SQL statement, regardless of the actual
7767** ON CONFLICT mode specified.
7768**
7769** If X is non-zero, then the virtual table implementation guarantees
7770** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
7771** any modifications to internal or persistent data structures have been made.
7772** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
7773** is able to roll back a statement or database transaction, and abandon
7774** or continue processing the current SQL statement as appropriate.
7775** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
7776** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
7777** had been ABORT.
7778**
7779** Virtual table implementations that are required to handle OR REPLACE
7780** must do so within the [xUpdate] method. If a call to the
7781** [sqlite3_vtab_on_conflict()] function indicates that the current ON
7782** CONFLICT policy is REPLACE, the virtual table implementation should
7783** silently replace the appropriate rows within the xUpdate callback and
7784** return SQLITE_OK. Or, if this is not possible, it may return
7785** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
7786** constraint handling.
7787** </dl>
7788*/
7789#define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
7790
7791/*
7792** CAPI3REF: Determine The Virtual Table Conflict Policy
7793**
7794** This function may only be called from within a call to the [xUpdate] method
7795** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
7796** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
7797** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
7798** of the SQL statement that triggered the call to the [xUpdate] method of the
7799** [virtual table].
7800*/
7801SQLITE_API int SQLITE_STDCALL sqlite3_vtab_on_conflict(sqlite3 *);
7802
7803/*
7804** CAPI3REF: Conflict resolution modes
7805** KEYWORDS: {conflict resolution mode}
7806**
7807** These constants are returned by [sqlite3_vtab_on_conflict()] to
7808** inform a [virtual table] implementation what the [ON CONFLICT] mode
7809** is for the SQL statement being evaluated.
7810**
7811** Note that the [SQLITE_IGNORE] constant is also used as a potential
7812** return value from the [sqlite3_set_authorizer()] callback and that
7813** [SQLITE_ABORT] is also a [result code].
7814*/
7815#define SQLITE_ROLLBACK 1
7816/* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
7817#define SQLITE_FAIL 3
7818/* #define SQLITE_ABORT 4 // Also an error code */
7819#define SQLITE_REPLACE 5
7820
7821/*
7822** CAPI3REF: Prepared Statement Scan Status Opcodes
7823** KEYWORDS: {scanstatus options}
7824**
7825** The following constants can be used for the T parameter to the
7826** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
7827** different metric for sqlite3_stmt_scanstatus() to return.
7828**
7829** When the value returned to V is a string, space to hold that string is
7830** managed by the prepared statement S and will be automatically freed when
7831** S is finalized.
7832**
7833** <dl>
7834** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
7835** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be
7836** set to the total number of times that the X-th loop has run.</dd>
7837**
7838** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
7839** <dd>^The [sqlite3_int64] variable pointed to by the T parameter will be set
7840** to the total number of rows examined by all iterations of the X-th loop.</dd>
7841**
7842** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
7843** <dd>^The "double" variable pointed to by the T parameter will be set to the
7844** query planner's estimate for the average number of rows output from each
7845** iteration of the X-th loop. If the query planner's estimates was accurate,
7846** then this value will approximate the quotient NVISIT/NLOOP and the
7847** product of this value for all prior loops with the same SELECTID will
7848** be the NLOOP value for the current loop.
7849**
7850** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
7851** <dd>^The "const char *" variable pointed to by the T parameter will be set
7852** to a zero-terminated UTF-8 string containing the name of the index or table
7853** used for the X-th loop.
7854**
7855** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
7856** <dd>^The "const char *" variable pointed to by the T parameter will be set
7857** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
7858** description for the X-th loop.
7859**
7860** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECT</dt>
7861** <dd>^The "int" variable pointed to by the T parameter will be set to the
7862** "select-id" for the X-th loop. The select-id identifies which query or
7863** subquery the loop is part of. The main query has a select-id of zero.
7864** The select-id is the same value as is output in the first column
7865** of an [EXPLAIN QUERY PLAN] query.
7866** </dl>
7867*/
7868#define SQLITE_SCANSTAT_NLOOP 0
7869#define SQLITE_SCANSTAT_NVISIT 1
7870#define SQLITE_SCANSTAT_EST 2
7871#define SQLITE_SCANSTAT_NAME 3
7872#define SQLITE_SCANSTAT_EXPLAIN 4
7873#define SQLITE_SCANSTAT_SELECTID 5
7874
7875/*
7876** CAPI3REF: Prepared Statement Scan Status
7877** METHOD: sqlite3_stmt
7878**
7879** This interface returns information about the predicted and measured
7880** performance for pStmt. Advanced applications can use this
7881** interface to compare the predicted and the measured performance and
7882** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
7883**
7884** Since this interface is expected to be rarely used, it is only
7885** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
7886** compile-time option.
7887**
7888** The "iScanStatusOp" parameter determines which status information to return.
7889** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
7890** of this interface is undefined.
7891** ^The requested measurement is written into a variable pointed to by
7892** the "pOut" parameter.
7893** Parameter "idx" identifies the specific loop to retrieve statistics for.
7894** Loops are numbered starting from zero. ^If idx is out of range - less than
7895** zero or greater than or equal to the total number of loops used to implement
7896** the statement - a non-zero value is returned and the variable that pOut
7897** points to is unchanged.
7898**
7899** ^Statistics might not be available for all loops in all statements. ^In cases
7900** where there exist loops with no available statistics, this function behaves
7901** as if the loop did not exist - it returns non-zero and leave the variable
7902** that pOut points to unchanged.
7903**
7904** See also: [sqlite3_stmt_scanstatus_reset()]
7905*/
7906SQLITE_API int SQLITE_STDCALL sqlite3_stmt_scanstatus(
7907 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
7908 int idx, /* Index of loop to report on */
7909 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
7910 void *pOut /* Result written here */
7911);
7912
7913/*
7914** CAPI3REF: Zero Scan-Status Counters
7915** METHOD: sqlite3_stmt
7916**
7917** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
7918**
7919** This API is only available if the library is built with pre-processor
7920** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
7921*/
7922SQLITE_API void SQLITE_STDCALL sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
7923
7924/*
7925** CAPI3REF: Flush caches to disk mid-transaction
7926**
7927** ^If a write-transaction is open on [database connection] D when the
7928** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
7929** pages in the pager-cache that are not currently in use are written out
7930** to disk. A dirty page may be in use if a database cursor created by an
7931** active SQL statement is reading from it, or if it is page 1 of a database
7932** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
7933** interface flushes caches for all schemas - "main", "temp", and
7934** any [attached] databases.
7935**
7936** ^If this function needs to obtain extra database locks before dirty pages
7937** can be flushed to disk, it does so. ^If those locks cannot be obtained
7938** immediately and there is a busy-handler callback configured, it is invoked
7939** in the usual manner. ^If the required lock still cannot be obtained, then
7940** the database is skipped and an attempt made to flush any dirty pages
7941** belonging to the next (if any) database. ^If any databases are skipped
7942** because locks cannot be obtained, but no other error occurs, this
7943** function returns SQLITE_BUSY.
7944**
7945** ^If any other error occurs while flushing dirty pages to disk (for
7946** example an IO error or out-of-memory condition), then processing is
7947** abandoned and an SQLite [error code] is returned to the caller immediately.
7948**
7949** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
7950**
7951** ^This function does not set the database handle error code or message
7952** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
7953*/
7954SQLITE_API int SQLITE_STDCALL sqlite3_db_cacheflush(sqlite3*);
7955
7956/*
7957** CAPI3REF: The pre-update hook.
7958**
7959** ^These interfaces are only available if SQLite is compiled using the
7960** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
7961**
7962** ^The [sqlite3_preupdate_hook()] interface registers a callback function
7963** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
7964** on a [rowid table].
7965** ^At most one preupdate hook may be registered at a time on a single
7966** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
7967** the previous setting.
7968** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
7969** with a NULL pointer as the second parameter.
7970** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
7971** the first parameter to callbacks.
7972**
7973** ^The preupdate hook only fires for changes to [rowid tables]; the preupdate
7974** hook is not invoked for changes to [virtual tables] or [WITHOUT ROWID]
7975** tables.
7976**
7977** ^The second parameter to the preupdate callback is a pointer to
7978** the [database connection] that registered the preupdate hook.
7979** ^The third parameter to the preupdate callback is one of the constants
7980** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to indentify the
7981** kind of update operation that is about to occur.
7982** ^(The fourth parameter to the preupdate callback is the name of the
7983** database within the database connection that is being modified. This
7984** will be "main" for the main database or "temp" for TEMP tables or
7985** the name given after the AS keyword in the [ATTACH] statement for attached
7986** databases.)^
7987** ^The fifth parameter to the preupdate callback is the name of the
7988** table that is being modified.
7989** ^The sixth parameter to the preupdate callback is the initial [rowid] of the
7990** row being changes for SQLITE_UPDATE and SQLITE_DELETE changes and is
7991** undefined for SQLITE_INSERT changes.
7992** ^The seventh parameter to the preupdate callback is the final [rowid] of
7993** the row being changed for SQLITE_UPDATE and SQLITE_INSERT changes and is
7994** undefined for SQLITE_DELETE changes.
7995**
7996** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
7997** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
7998** provide additional information about a preupdate event. These routines
7999** may only be called from within a preupdate callback. Invoking any of
8000** these routines from outside of a preupdate callback or with a
8001** [database connection] pointer that is different from the one supplied
8002** to the preupdate callback results in undefined and probably undesirable
8003** behavior.
8004**
8005** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
8006** in the row that is being inserted, updated, or deleted.
8007**
8008** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
8009** a [protected sqlite3_value] that contains the value of the Nth column of
8010** the table row before it is updated. The N parameter must be between 0
8011** and one less than the number of columns or the behavior will be
8012** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
8013** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
8014** behavior is undefined. The [sqlite3_value] that P points to
8015** will be destroyed when the preupdate callback returns.
8016**
8017** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
8018** a [protected sqlite3_value] that contains the value of the Nth column of
8019** the table row after it is updated. The N parameter must be between 0
8020** and one less than the number of columns or the behavior will be
8021** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
8022** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
8023** behavior is undefined. The [sqlite3_value] that P points to
8024** will be destroyed when the preupdate callback returns.
8025**
8026** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
8027** callback was invoked as a result of a direct insert, update, or delete
8028** operation; or 1 for inserts, updates, or deletes invoked by top-level
8029** triggers; or 2 for changes resulting from triggers called by top-level
8030** triggers; and so forth.
8031**
8032** See also: [sqlite3_update_hook()]
8033*/
8034SQLITE_API SQLITE_EXPERIMENTAL void *SQLITE_STDCALL sqlite3_preupdate_hook(
8035 sqlite3 *db,
8036 void(*xPreUpdate)(
8037 void *pCtx, /* Copy of third arg to preupdate_hook() */
8038 sqlite3 *db, /* Database handle */
8039 int op, /* SQLITE_UPDATE, DELETE or INSERT */
8040 char const *zDb, /* Database name */
8041 char const *zName, /* Table name */
8042 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
8043 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
8044 ),
8045 void*
8046);
8047SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
8048SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_count(sqlite3 *);
8049SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_depth(sqlite3 *);
8050SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
8051
8052/*
8053** CAPI3REF: Low-level system error code
8054**
8055** ^Attempt to return the underlying operating system error code or error
8056** number that caused the most recent I/O error or failure to open a file.
8057** The return value is OS-dependent. For example, on unix systems, after
8058** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
8059** called to get back the underlying "errno" that caused the problem, such
8060** as ENOSPC, EAUTH, EISDIR, and so forth.
8061*/
8062SQLITE_API int SQLITE_STDCALL sqlite3_system_errno(sqlite3*);
8063
8064/*
8065** CAPI3REF: Database Snapshot
8066** KEYWORDS: {snapshot}
8067** EXPERIMENTAL
8068**
8069** An instance of the snapshot object records the state of a [WAL mode]
8070** database for some specific point in history.
8071**
8072** In [WAL mode], multiple [database connections] that are open on the
8073** same database file can each be reading a different historical version
8074** of the database file. When a [database connection] begins a read
8075** transaction, that connection sees an unchanging copy of the database
8076** as it existed for the point in time when the transaction first started.
8077** Subsequent changes to the database from other connections are not seen
8078** by the reader until a new read transaction is started.
8079**
8080** The sqlite3_snapshot object records state information about an historical
8081** version of the database file so that it is possible to later open a new read
8082** transaction that sees that historical version of the database rather than
8083** the most recent version.
8084**
8085** The constructor for this object is [sqlite3_snapshot_get()]. The
8086** [sqlite3_snapshot_open()] method causes a fresh read transaction to refer
8087** to an historical snapshot (if possible). The destructor for
8088** sqlite3_snapshot objects is [sqlite3_snapshot_free()].
8089*/
8090typedef struct sqlite3_snapshot sqlite3_snapshot;
8091
8092/*
8093** CAPI3REF: Record A Database Snapshot
8094** EXPERIMENTAL
8095**
8096** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
8097** new [sqlite3_snapshot] object that records the current state of
8098** schema S in database connection D. ^On success, the
8099** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
8100** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
8101** ^If schema S of [database connection] D is not a [WAL mode] database
8102** that is in a read transaction, then [sqlite3_snapshot_get(D,S,P)]
8103** leaves the *P value unchanged and returns an appropriate [error code].
8104**
8105** The [sqlite3_snapshot] object returned from a successful call to
8106** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
8107** to avoid a memory leak.
8108**
8109** The [sqlite3_snapshot_get()] interface is only available when the
8110** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8111*/
8112SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_get(
8113 sqlite3 *db,
8114 const char *zSchema,
8115 sqlite3_snapshot **ppSnapshot
8116);
8117
8118/*
8119** CAPI3REF: Start a read transaction on an historical snapshot
8120** EXPERIMENTAL
8121**
8122** ^The [sqlite3_snapshot_open(D,S,P)] interface starts a
8123** read transaction for schema S of
8124** [database connection] D such that the read transaction
8125** refers to historical [snapshot] P, rather than the most
8126** recent change to the database.
8127** ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK on success
8128** or an appropriate [error code] if it fails.
8129**
8130** ^In order to succeed, a call to [sqlite3_snapshot_open(D,S,P)] must be
8131** the first operation following the [BEGIN] that takes the schema S
8132** out of [autocommit mode].
8133** ^In other words, schema S must not currently be in
8134** a transaction for [sqlite3_snapshot_open(D,S,P)] to work, but the
8135** database connection D must be out of [autocommit mode].
8136** ^A [snapshot] will fail to open if it has been overwritten by a
8137** [checkpoint].
8138** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
8139** database connection D does not know that the database file for
8140** schema S is in [WAL mode]. A database connection might not know
8141** that the database file is in [WAL mode] if there has been no prior
8142** I/O on that database connection, or if the database entered [WAL mode]
8143** after the most recent I/O on the database connection.)^
8144** (Hint: Run "[PRAGMA application_id]" against a newly opened
8145** database connection in order to make it ready to use snapshots.)
8146**
8147** The [sqlite3_snapshot_open()] interface is only available when the
8148** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8149*/
8150SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_open(
8151 sqlite3 *db,
8152 const char *zSchema,
8153 sqlite3_snapshot *pSnapshot
8154);
8155
8156/*
8157** CAPI3REF: Destroy a snapshot
8158** EXPERIMENTAL
8159**
8160** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
8161** The application must eventually free every [sqlite3_snapshot] object
8162** using this routine to avoid a memory leak.
8163**
8164** The [sqlite3_snapshot_free()] interface is only available when the
8165** SQLITE_ENABLE_SNAPSHOT compile-time option is used.
8166*/
8167SQLITE_API SQLITE_EXPERIMENTAL void SQLITE_STDCALL sqlite3_snapshot_free(sqlite3_snapshot*);
8168
8169/*
8170** CAPI3REF: Compare the ages of two snapshot handles.
8171** EXPERIMENTAL
8172**
8173** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
8174** of two valid snapshot handles.
8175**
8176** If the two snapshot handles are not associated with the same database
8177** file, the result of the comparison is undefined.
8178**
8179** Additionally, the result of the comparison is only valid if both of the
8180** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
8181** last time the wal file was deleted. The wal file is deleted when the
8182** database is changed back to rollback mode or when the number of database
8183** clients drops to zero. If either snapshot handle was obtained before the
8184** wal file was last deleted, the value returned by this function
8185** is undefined.
8186**
8187** Otherwise, this API returns a negative value if P1 refers to an older
8188** snapshot than P2, zero if the two handles refer to the same database
8189** snapshot, and a positive value if P1 is a newer snapshot than P2.
8190*/
8191SQLITE_API SQLITE_EXPERIMENTAL int SQLITE_STDCALL sqlite3_snapshot_cmp(
8192 sqlite3_snapshot *p1,
8193 sqlite3_snapshot *p2
8194);
8195
8196/*
8197** Undo the hack that converts floating point types to integer for
8198** builds on processors without floating point support.
8199*/
8200#ifdef SQLITE_OMIT_FLOATING_POINT
8201# undef double
8202#endif
8203
8204#ifdef __cplusplus
8205} /* End of the 'extern "C"' block */
8206#endif
8207#endif /* _SQLITE3_H_ */
8208
8209/******** Begin file sqlite3rtree.h *********/
8210/*
8211** 2010 August 30
8212**
8213** The author disclaims copyright to this source code. In place of
8214** a legal notice, here is a blessing:
8215**
8216** May you do good and not evil.
8217** May you find forgiveness for yourself and forgive others.
8218** May you share freely, never taking more than you give.
8219**
8220*************************************************************************
8221*/
8222
8223#ifndef _SQLITE3RTREE_H_
8224#define _SQLITE3RTREE_H_
8225
8226
8227#ifdef __cplusplus
8228extern "C" {
8229#endif
8230
8231typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
8232typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
8233
8234/* The double-precision datatype used by RTree depends on the
8235** SQLITE_RTREE_INT_ONLY compile-time option.
8236*/
8237#ifdef SQLITE_RTREE_INT_ONLY
8238 typedef sqlite3_int64 sqlite3_rtree_dbl;
8239#else
8240 typedef double sqlite3_rtree_dbl;
8241#endif
8242
8243/*
8244** Register a geometry callback named zGeom that can be used as part of an
8245** R-Tree geometry query as follows:
8246**
8247** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
8248*/
8249SQLITE_API int SQLITE_STDCALL sqlite3_rtree_geometry_callback(
8250 sqlite3 *db,
8251 const char *zGeom,
8252 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
8253 void *pContext
8254);
8255
8256
8257/*
8258** A pointer to a structure of the following type is passed as the first
8259** argument to callbacks registered using rtree_geometry_callback().
8260*/
8261struct sqlite3_rtree_geometry {
8262 void *pContext; /* Copy of pContext passed to s_r_g_c() */
8263 int nParam; /* Size of array aParam[] */
8264 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
8265 void *pUser; /* Callback implementation user data */
8266 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
8267};
8268
8269/*
8270** Register a 2nd-generation geometry callback named zScore that can be
8271** used as part of an R-Tree geometry query as follows:
8272**
8273** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
8274*/
8275SQLITE_API int SQLITE_STDCALL sqlite3_rtree_query_callback(
8276 sqlite3 *db,
8277 const char *zQueryFunc,
8278 int (*xQueryFunc)(sqlite3_rtree_query_info*),
8279 void *pContext,
8280 void (*xDestructor)(void*)
8281);
8282
8283
8284/*
8285** A pointer to a structure of the following type is passed as the
8286** argument to scored geometry callback registered using
8287** sqlite3_rtree_query_callback().
8288**
8289** Note that the first 5 fields of this structure are identical to
8290** sqlite3_rtree_geometry. This structure is a subclass of
8291** sqlite3_rtree_geometry.
8292*/
8293struct sqlite3_rtree_query_info {
8294 void *pContext; /* pContext from when function registered */
8295 int nParam; /* Number of function parameters */
8296 sqlite3_rtree_dbl *aParam; /* value of function parameters */
8297 void *pUser; /* callback can use this, if desired */
8298 void (*xDelUser)(void*); /* function to free pUser */
8299 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
8300 unsigned int *anQueue; /* Number of pending entries in the queue */
8301 int nCoord; /* Number of coordinates */
8302 int iLevel; /* Level of current node or entry */
8303 int mxLevel; /* The largest iLevel value in the tree */
8304 sqlite3_int64 iRowid; /* Rowid for current entry */
8305 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
8306 int eParentWithin; /* Visibility of parent node */
8307 int eWithin; /* OUT: Visiblity */
8308 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
8309 /* The following fields are only available in 3.8.11 and later */
8310 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
8311};
8312
8313/*
8314** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
8315*/
8316#define NOT_WITHIN 0 /* Object completely outside of query region */
8317#define PARTLY_WITHIN 1 /* Object partially overlaps query region */
8318#define FULLY_WITHIN 2 /* Object fully contained within query region */
8319
8320
8321#ifdef __cplusplus
8322} /* end of the 'extern "C"' block */
8323#endif
8324
8325#endif /* ifndef _SQLITE3RTREE_H_ */
8326
8327/******** End of sqlite3rtree.h *********/
8328/******** Begin file sqlite3session.h *********/
8329
8330#if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
8331#define __SQLITESESSION_H_ 1
8332
8333/*
8334** Make sure we can call this stuff from C++.
8335*/
8336#ifdef __cplusplus
8337extern "C" {
8338#endif
8339
8340
8341/*
8342** CAPI3REF: Session Object Handle
8343*/
8344typedef struct sqlite3_session sqlite3_session;
8345
8346/*
8347** CAPI3REF: Changeset Iterator Handle
8348*/
8349typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
8350
8351/*
8352** CAPI3REF: Create A New Session Object
8353**
8354** Create a new session object attached to database handle db. If successful,
8355** a pointer to the new object is written to *ppSession and SQLITE_OK is
8356** returned. If an error occurs, *ppSession is set to NULL and an SQLite
8357** error code (e.g. SQLITE_NOMEM) is returned.
8358**
8359** It is possible to create multiple session objects attached to a single
8360** database handle.
8361**
8362** Session objects created using this function should be deleted using the
8363** [sqlite3session_delete()] function before the database handle that they
8364** are attached to is itself closed. If the database handle is closed before
8365** the session object is deleted, then the results of calling any session
8366** module function, including [sqlite3session_delete()] on the session object
8367** are undefined.
8368**
8369** Because the session module uses the [sqlite3_preupdate_hook()] API, it
8370** is not possible for an application to register a pre-update hook on a
8371** database handle that has one or more session objects attached. Nor is
8372** it possible to create a session object attached to a database handle for
8373** which a pre-update hook is already defined. The results of attempting
8374** either of these things are undefined.
8375**
8376** The session object will be used to create changesets for tables in
8377** database zDb, where zDb is either "main", or "temp", or the name of an
8378** attached database. It is not an error if database zDb is not attached
8379** to the database when the session object is created.
8380*/
8381int sqlite3session_create(
8382 sqlite3 *db, /* Database handle */
8383 const char *zDb, /* Name of db (e.g. "main") */
8384 sqlite3_session **ppSession /* OUT: New session object */
8385);
8386
8387/*
8388** CAPI3REF: Delete A Session Object
8389**
8390** Delete a session object previously allocated using
8391** [sqlite3session_create()]. Once a session object has been deleted, the
8392** results of attempting to use pSession with any other session module
8393** function are undefined.
8394**
8395** Session objects must be deleted before the database handle to which they
8396** are attached is closed. Refer to the documentation for
8397** [sqlite3session_create()] for details.
8398*/
8399void sqlite3session_delete(sqlite3_session *pSession);
8400
8401
8402/*
8403** CAPI3REF: Enable Or Disable A Session Object
8404**
8405** Enable or disable the recording of changes by a session object. When
8406** enabled, a session object records changes made to the database. When
8407** disabled - it does not. A newly created session object is enabled.
8408** Refer to the documentation for [sqlite3session_changeset()] for further
8409** details regarding how enabling and disabling a session object affects
8410** the eventual changesets.
8411**
8412** Passing zero to this function disables the session. Passing a value
8413** greater than zero enables it. Passing a value less than zero is a
8414** no-op, and may be used to query the current state of the session.
8415**
8416** The return value indicates the final state of the session object: 0 if
8417** the session is disabled, or 1 if it is enabled.
8418*/
8419int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
8420
8421/*
8422** CAPI3REF: Set Or Clear the Indirect Change Flag
8423**
8424** Each change recorded by a session object is marked as either direct or
8425** indirect. A change is marked as indirect if either:
8426**
8427** <ul>
8428** <li> The session object "indirect" flag is set when the change is
8429** made, or
8430** <li> The change is made by an SQL trigger or foreign key action
8431** instead of directly as a result of a users SQL statement.
8432** </ul>
8433**
8434** If a single row is affected by more than one operation within a session,
8435** then the change is considered indirect if all operations meet the criteria
8436** for an indirect change above, or direct otherwise.
8437**
8438** This function is used to set, clear or query the session object indirect
8439** flag. If the second argument passed to this function is zero, then the
8440** indirect flag is cleared. If it is greater than zero, the indirect flag
8441** is set. Passing a value less than zero does not modify the current value
8442** of the indirect flag, and may be used to query the current state of the
8443** indirect flag for the specified session object.
8444**
8445** The return value indicates the final state of the indirect flag: 0 if
8446** it is clear, or 1 if it is set.
8447*/
8448int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
8449
8450/*
8451** CAPI3REF: Attach A Table To A Session Object
8452**
8453** If argument zTab is not NULL, then it is the name of a table to attach
8454** to the session object passed as the first argument. All subsequent changes
8455** made to the table while the session object is enabled will be recorded. See
8456** documentation for [sqlite3session_changeset()] for further details.
8457**
8458** Or, if argument zTab is NULL, then changes are recorded for all tables
8459** in the database. If additional tables are added to the database (by
8460** executing "CREATE TABLE" statements) after this call is made, changes for
8461** the new tables are also recorded.
8462**
8463** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
8464** defined as part of their CREATE TABLE statement. It does not matter if the
8465** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
8466** KEY may consist of a single column, or may be a composite key.
8467**
8468** It is not an error if the named table does not exist in the database. Nor
8469** is it an error if the named table does not have a PRIMARY KEY. However,
8470** no changes will be recorded in either of these scenarios.
8471**
8472** Changes are not recorded for individual rows that have NULL values stored
8473** in one or more of their PRIMARY KEY columns.
8474**
8475** SQLITE_OK is returned if the call completes without error. Or, if an error
8476** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
8477*/
8478int sqlite3session_attach(
8479 sqlite3_session *pSession, /* Session object */
8480 const char *zTab /* Table name */
8481);
8482
8483/*
8484** CAPI3REF: Set a table filter on a Session Object.
8485**
8486** The second argument (xFilter) is the "filter callback". For changes to rows
8487** in tables that are not attached to the Session oject, the filter is called
8488** to determine whether changes to the table's rows should be tracked or not.
8489** If xFilter returns 0, changes is not tracked. Note that once a table is
8490** attached, xFilter will not be called again.
8491*/
8492void sqlite3session_table_filter(
8493 sqlite3_session *pSession, /* Session object */
8494 int(*xFilter)(
8495 void *pCtx, /* Copy of third arg to _filter_table() */
8496 const char *zTab /* Table name */
8497 ),
8498 void *pCtx /* First argument passed to xFilter */
8499);
8500
8501/*
8502** CAPI3REF: Generate A Changeset From A Session Object
8503**
8504** Obtain a changeset containing changes to the tables attached to the
8505** session object passed as the first argument. If successful,
8506** set *ppChangeset to point to a buffer containing the changeset
8507** and *pnChangeset to the size of the changeset in bytes before returning
8508** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
8509** zero and return an SQLite error code.
8510**
8511** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
8512** each representing a change to a single row of an attached table. An INSERT
8513** change contains the values of each field of a new database row. A DELETE
8514** contains the original values of each field of a deleted database row. An
8515** UPDATE change contains the original values of each field of an updated
8516** database row along with the updated values for each updated non-primary-key
8517** column. It is not possible for an UPDATE change to represent a change that
8518** modifies the values of primary key columns. If such a change is made, it
8519** is represented in a changeset as a DELETE followed by an INSERT.
8520**
8521** Changes are not recorded for rows that have NULL values stored in one or
8522** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
8523** no corresponding change is present in the changesets returned by this
8524** function. If an existing row with one or more NULL values stored in
8525** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
8526** only an INSERT is appears in the changeset. Similarly, if an existing row
8527** with non-NULL PRIMARY KEY values is updated so that one or more of its
8528** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
8529** DELETE change only.
8530**
8531** The contents of a changeset may be traversed using an iterator created
8532** using the [sqlite3changeset_start()] API. A changeset may be applied to
8533** a database with a compatible schema using the [sqlite3changeset_apply()]
8534** API.
8535**
8536** Within a changeset generated by this function, all changes related to a
8537** single table are grouped together. In other words, when iterating through
8538** a changeset or when applying a changeset to a database, all changes related
8539** to a single table are processed before moving on to the next table. Tables
8540** are sorted in the same order in which they were attached (or auto-attached)
8541** to the sqlite3_session object. The order in which the changes related to
8542** a single table are stored is undefined.
8543**
8544** Following a successful call to this function, it is the responsibility of
8545** the caller to eventually free the buffer that *ppChangeset points to using
8546** [sqlite3_free()].
8547**
8548** <h3>Changeset Generation</h3>
8549**
8550** Once a table has been attached to a session object, the session object
8551** records the primary key values of all new rows inserted into the table.
8552** It also records the original primary key and other column values of any
8553** deleted or updated rows. For each unique primary key value, data is only
8554** recorded once - the first time a row with said primary key is inserted,
8555** updated or deleted in the lifetime of the session.
8556**
8557** There is one exception to the previous paragraph: when a row is inserted,
8558** updated or deleted, if one or more of its primary key columns contain a
8559** NULL value, no record of the change is made.
8560**
8561** The session object therefore accumulates two types of records - those
8562** that consist of primary key values only (created when the user inserts
8563** a new record) and those that consist of the primary key values and the
8564** original values of other table columns (created when the users deletes
8565** or updates a record).
8566**
8567** When this function is called, the requested changeset is created using
8568** both the accumulated records and the current contents of the database
8569** file. Specifically:
8570**
8571** <ul>
8572** <li> For each record generated by an insert, the database is queried
8573** for a row with a matching primary key. If one is found, an INSERT
8574** change is added to the changeset. If no such row is found, no change
8575** is added to the changeset.
8576**
8577** <li> For each record generated by an update or delete, the database is
8578** queried for a row with a matching primary key. If such a row is
8579** found and one or more of the non-primary key fields have been
8580** modified from their original values, an UPDATE change is added to
8581** the changeset. Or, if no such row is found in the table, a DELETE
8582** change is added to the changeset. If there is a row with a matching
8583** primary key in the database, but all fields contain their original
8584** values, no change is added to the changeset.
8585** </ul>
8586**
8587** This means, amongst other things, that if a row is inserted and then later
8588** deleted while a session object is active, neither the insert nor the delete
8589** will be present in the changeset. Or if a row is deleted and then later a
8590** row with the same primary key values inserted while a session object is
8591** active, the resulting changeset will contain an UPDATE change instead of
8592** a DELETE and an INSERT.
8593**
8594** When a session object is disabled (see the [sqlite3session_enable()] API),
8595** it does not accumulate records when rows are inserted, updated or deleted.
8596** This may appear to have some counter-intuitive effects if a single row
8597** is written to more than once during a session. For example, if a row
8598** is inserted while a session object is enabled, then later deleted while
8599** the same session object is disabled, no INSERT record will appear in the
8600** changeset, even though the delete took place while the session was disabled.
8601** Or, if one field of a row is updated while a session is disabled, and
8602** another field of the same row is updated while the session is enabled, the
8603** resulting changeset will contain an UPDATE change that updates both fields.
8604*/
8605int sqlite3session_changeset(
8606 sqlite3_session *pSession, /* Session object */
8607 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
8608 void **ppChangeset /* OUT: Buffer containing changeset */
8609);
8610
8611/*
8612** CAPI3REF: Load The Difference Between Tables Into A Session
8613**
8614** If it is not already attached to the session object passed as the first
8615** argument, this function attaches table zTbl in the same manner as the
8616** [sqlite3session_attach()] function. If zTbl does not exist, or if it
8617** does not have a primary key, this function is a no-op (but does not return
8618** an error).
8619**
8620** Argument zFromDb must be the name of a database ("main", "temp" etc.)
8621** attached to the same database handle as the session object that contains
8622** a table compatible with the table attached to the session by this function.
8623** A table is considered compatible if it:
8624**
8625** <ul>
8626** <li> Has the same name,
8627** <li> Has the same set of columns declared in the same order, and
8628** <li> Has the same PRIMARY KEY definition.
8629** </ul>
8630**
8631** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
8632** are compatible but do not have any PRIMARY KEY columns, it is not an error
8633** but no changes are added to the session object. As with other session
8634** APIs, tables without PRIMARY KEYs are simply ignored.
8635**
8636** This function adds a set of changes to the session object that could be
8637** used to update the table in database zFrom (call this the "from-table")
8638** so that its content is the same as the table attached to the session
8639** object (call this the "to-table"). Specifically:
8640**
8641** <ul>
8642** <li> For each row (primary key) that exists in the to-table but not in
8643** the from-table, an INSERT record is added to the session object.
8644**
8645** <li> For each row (primary key) that exists in the to-table but not in
8646** the from-table, a DELETE record is added to the session object.
8647**
8648** <li> For each row (primary key) that exists in both tables, but features
8649** different in each, an UPDATE record is added to the session.
8650** </ul>
8651**
8652** To clarify, if this function is called and then a changeset constructed
8653** using [sqlite3session_changeset()], then after applying that changeset to
8654** database zFrom the contents of the two compatible tables would be
8655** identical.
8656**
8657** It an error if database zFrom does not exist or does not contain the
8658** required compatible table.
8659**
8660** If the operation successful, SQLITE_OK is returned. Otherwise, an SQLite
8661** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
8662** may be set to point to a buffer containing an English language error
8663** message. It is the responsibility of the caller to free this buffer using
8664** sqlite3_free().
8665*/
8666int sqlite3session_diff(
8667 sqlite3_session *pSession,
8668 const char *zFromDb,
8669 const char *zTbl,
8670 char **pzErrMsg
8671);
8672
8673
8674/*
8675** CAPI3REF: Generate A Patchset From A Session Object
8676**
8677** The differences between a patchset and a changeset are that:
8678**
8679** <ul>
8680** <li> DELETE records consist of the primary key fields only. The
8681** original values of other fields are omitted.
8682** <li> The original values of any modified fields are omitted from
8683** UPDATE records.
8684** </ul>
8685**
8686** A patchset blob may be used with up to date versions of all
8687** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
8688** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
8689** attempting to use a patchset blob with old versions of the
8690** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
8691**
8692** Because the non-primary key "old.*" fields are omitted, no
8693** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
8694** is passed to the sqlite3changeset_apply() API. Other conflict types work
8695** in the same way as for changesets.
8696**
8697** Changes within a patchset are ordered in the same way as for changesets
8698** generated by the sqlite3session_changeset() function (i.e. all changes for
8699** a single table are grouped together, tables appear in the order in which
8700** they were attached to the session object).
8701*/
8702int sqlite3session_patchset(
8703 sqlite3_session *pSession, /* Session object */
8704 int *pnPatchset, /* OUT: Size of buffer at *ppChangeset */
8705 void **ppPatchset /* OUT: Buffer containing changeset */
8706);
8707
8708/*
8709** CAPI3REF: Test if a changeset has recorded any changes.
8710**
8711** Return non-zero if no changes to attached tables have been recorded by
8712** the session object passed as the first argument. Otherwise, if one or
8713** more changes have been recorded, return zero.
8714**
8715** Even if this function returns zero, it is possible that calling
8716** [sqlite3session_changeset()] on the session handle may still return a
8717** changeset that contains no changes. This can happen when a row in
8718** an attached table is modified and then later on the original values
8719** are restored. However, if this function returns non-zero, then it is
8720** guaranteed that a call to sqlite3session_changeset() will return a
8721** changeset containing zero changes.
8722*/
8723int sqlite3session_isempty(sqlite3_session *pSession);
8724
8725/*
8726** CAPI3REF: Create An Iterator To Traverse A Changeset
8727**
8728** Create an iterator used to iterate through the contents of a changeset.
8729** If successful, *pp is set to point to the iterator handle and SQLITE_OK
8730** is returned. Otherwise, if an error occurs, *pp is set to zero and an
8731** SQLite error code is returned.
8732**
8733** The following functions can be used to advance and query a changeset
8734** iterator created by this function:
8735**
8736** <ul>
8737** <li> [sqlite3changeset_next()]
8738** <li> [sqlite3changeset_op()]
8739** <li> [sqlite3changeset_new()]
8740** <li> [sqlite3changeset_old()]
8741** </ul>
8742**
8743** It is the responsibility of the caller to eventually destroy the iterator
8744** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
8745** changeset (pChangeset) must remain valid until after the iterator is
8746** destroyed.
8747**
8748** Assuming the changeset blob was created by one of the
8749** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
8750** [sqlite3changeset_invert()] functions, all changes within the changeset
8751** that apply to a single table are grouped together. This means that when
8752** an application iterates through a changeset using an iterator created by
8753** this function, all changes that relate to a single table are visted
8754** consecutively. There is no chance that the iterator will visit a change
8755** the applies to table X, then one for table Y, and then later on visit
8756** another change for table X.
8757*/
8758int sqlite3changeset_start(
8759 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
8760 int nChangeset, /* Size of changeset blob in bytes */
8761 void *pChangeset /* Pointer to blob containing changeset */
8762);
8763
8764
8765/*
8766** CAPI3REF: Advance A Changeset Iterator
8767**
8768** This function may only be used with iterators created by function
8769** [sqlite3changeset_start()]. If it is called on an iterator passed to
8770** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
8771** is returned and the call has no effect.
8772**
8773** Immediately after an iterator is created by sqlite3changeset_start(), it
8774** does not point to any change in the changeset. Assuming the changeset
8775** is not empty, the first call to this function advances the iterator to
8776** point to the first change in the changeset. Each subsequent call advances
8777** the iterator to point to the next change in the changeset (if any). If
8778** no error occurs and the iterator points to a valid change after a call
8779** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
8780** Otherwise, if all changes in the changeset have already been visited,
8781** SQLITE_DONE is returned.
8782**
8783** If an error occurs, an SQLite error code is returned. Possible error
8784** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
8785** SQLITE_NOMEM.
8786*/
8787int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
8788
8789/*
8790** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
8791**
8792** The pIter argument passed to this function may either be an iterator
8793** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
8794** created by [sqlite3changeset_start()]. In the latter case, the most recent
8795** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
8796** is not the case, this function returns [SQLITE_MISUSE].
8797**
8798** If argument pzTab is not NULL, then *pzTab is set to point to a
8799** nul-terminated utf-8 encoded string containing the name of the table
8800** affected by the current change. The buffer remains valid until either
8801** sqlite3changeset_next() is called on the iterator or until the
8802** conflict-handler function returns. If pnCol is not NULL, then *pnCol is
8803** set to the number of columns in the table affected by the change. If
8804** pbIncorrect is not NULL, then *pbIndirect is set to true (1) if the change
8805** is an indirect change, or false (0) otherwise. See the documentation for
8806** [sqlite3session_indirect()] for a description of direct and indirect
8807** changes. Finally, if pOp is not NULL, then *pOp is set to one of
8808** [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE], depending on the
8809** type of change that the iterator currently points to.
8810**
8811** If no error occurs, SQLITE_OK is returned. If an error does occur, an
8812** SQLite error code is returned. The values of the output variables may not
8813** be trusted in this case.
8814*/
8815int sqlite3changeset_op(
8816 sqlite3_changeset_iter *pIter, /* Iterator object */
8817 const char **pzTab, /* OUT: Pointer to table name */
8818 int *pnCol, /* OUT: Number of columns in table */
8819 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
8820 int *pbIndirect /* OUT: True for an 'indirect' change */
8821);
8822
8823/*
8824** CAPI3REF: Obtain The Primary Key Definition Of A Table
8825**
8826** For each modified table, a changeset includes the following:
8827**
8828** <ul>
8829** <li> The number of columns in the table, and
8830** <li> Which of those columns make up the tables PRIMARY KEY.
8831** </ul>
8832**
8833** This function is used to find which columns comprise the PRIMARY KEY of
8834** the table modified by the change that iterator pIter currently points to.
8835** If successful, *pabPK is set to point to an array of nCol entries, where
8836** nCol is the number of columns in the table. Elements of *pabPK are set to
8837** 0x01 if the corresponding column is part of the tables primary key, or
8838** 0x00 if it is not.
8839**
8840** If argumet pnCol is not NULL, then *pnCol is set to the number of columns
8841** in the table.
8842**
8843** If this function is called when the iterator does not point to a valid
8844** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
8845** SQLITE_OK is returned and the output variables populated as described
8846** above.
8847*/
8848int sqlite3changeset_pk(
8849 sqlite3_changeset_iter *pIter, /* Iterator object */
8850 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
8851 int *pnCol /* OUT: Number of entries in output array */
8852);
8853
8854/*
8855** CAPI3REF: Obtain old.* Values From A Changeset Iterator
8856**
8857** The pIter argument passed to this function may either be an iterator
8858** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
8859** created by [sqlite3changeset_start()]. In the latter case, the most recent
8860** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
8861** Furthermore, it may only be called if the type of change that the iterator
8862** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
8863** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
8864**
8865** Argument iVal must be greater than or equal to 0, and less than the number
8866** of columns in the table affected by the current change. Otherwise,
8867** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
8868**
8869** If successful, this function sets *ppValue to point to a protected
8870** sqlite3_value object containing the iVal'th value from the vector of
8871** original row values stored as part of the UPDATE or DELETE change and
8872** returns SQLITE_OK. The name of the function comes from the fact that this
8873** is similar to the "old.*" columns available to update or delete triggers.
8874**
8875** If some other error occurs (e.g. an OOM condition), an SQLite error code
8876** is returned and *ppValue is set to NULL.
8877*/
8878int sqlite3changeset_old(
8879 sqlite3_changeset_iter *pIter, /* Changeset iterator */
8880 int iVal, /* Column number */
8881 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
8882);
8883
8884/*
8885** CAPI3REF: Obtain new.* Values From A Changeset Iterator
8886**
8887** The pIter argument passed to this function may either be an iterator
8888** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
8889** created by [sqlite3changeset_start()]. In the latter case, the most recent
8890** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
8891** Furthermore, it may only be called if the type of change that the iterator
8892** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
8893** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
8894**
8895** Argument iVal must be greater than or equal to 0, and less than the number
8896** of columns in the table affected by the current change. Otherwise,
8897** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
8898**
8899** If successful, this function sets *ppValue to point to a protected
8900** sqlite3_value object containing the iVal'th value from the vector of
8901** new row values stored as part of the UPDATE or INSERT change and
8902** returns SQLITE_OK. If the change is an UPDATE and does not include
8903** a new value for the requested column, *ppValue is set to NULL and
8904** SQLITE_OK returned. The name of the function comes from the fact that
8905** this is similar to the "new.*" columns available to update or delete
8906** triggers.
8907**
8908** If some other error occurs (e.g. an OOM condition), an SQLite error code
8909** is returned and *ppValue is set to NULL.
8910*/
8911int sqlite3changeset_new(
8912 sqlite3_changeset_iter *pIter, /* Changeset iterator */
8913 int iVal, /* Column number */
8914 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
8915);
8916
8917/*
8918** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
8919**
8920** This function should only be used with iterator objects passed to a
8921** conflict-handler callback by [sqlite3changeset_apply()] with either
8922** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
8923** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
8924** is set to NULL.
8925**
8926** Argument iVal must be greater than or equal to 0, and less than the number
8927** of columns in the table affected by the current change. Otherwise,
8928** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
8929**
8930** If successful, this function sets *ppValue to point to a protected
8931** sqlite3_value object containing the iVal'th value from the
8932** "conflicting row" associated with the current conflict-handler callback
8933** and returns SQLITE_OK.
8934**
8935** If some other error occurs (e.g. an OOM condition), an SQLite error code
8936** is returned and *ppValue is set to NULL.
8937*/
8938int sqlite3changeset_conflict(
8939 sqlite3_changeset_iter *pIter, /* Changeset iterator */
8940 int iVal, /* Column number */
8941 sqlite3_value **ppValue /* OUT: Value from conflicting row */
8942);
8943
8944/*
8945** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
8946**
8947** This function may only be called with an iterator passed to an
8948** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
8949** it sets the output variable to the total number of known foreign key
8950** violations in the destination database and returns SQLITE_OK.
8951**
8952** In all other cases this function returns SQLITE_MISUSE.
8953*/
8954int sqlite3changeset_fk_conflicts(
8955 sqlite3_changeset_iter *pIter, /* Changeset iterator */
8956 int *pnOut /* OUT: Number of FK violations */
8957);
8958
8959
8960/*
8961** CAPI3REF: Finalize A Changeset Iterator
8962**
8963** This function is used to finalize an iterator allocated with
8964** [sqlite3changeset_start()].
8965**
8966** This function should only be called on iterators created using the
8967** [sqlite3changeset_start()] function. If an application calls this
8968** function with an iterator passed to a conflict-handler by
8969** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
8970** call has no effect.
8971**
8972** If an error was encountered within a call to an sqlite3changeset_xxx()
8973** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
8974** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
8975** to that error is returned by this function. Otherwise, SQLITE_OK is
8976** returned. This is to allow the following pattern (pseudo-code):
8977**
8978** sqlite3changeset_start();
8979** while( SQLITE_ROW==sqlite3changeset_next() ){
8980** // Do something with change.
8981** }
8982** rc = sqlite3changeset_finalize();
8983** if( rc!=SQLITE_OK ){
8984** // An error has occurred
8985** }
8986*/
8987int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
8988
8989/*
8990** CAPI3REF: Invert A Changeset
8991**
8992** This function is used to "invert" a changeset object. Applying an inverted
8993** changeset to a database reverses the effects of applying the uninverted
8994** changeset. Specifically:
8995**
8996** <ul>
8997** <li> Each DELETE change is changed to an INSERT, and
8998** <li> Each INSERT change is changed to a DELETE, and
8999** <li> For each UPDATE change, the old.* and new.* values are exchanged.
9000** </ul>
9001**
9002** This function does not change the order in which changes appear within
9003** the changeset. It merely reverses the sense of each individual change.
9004**
9005** If successful, a pointer to a buffer containing the inverted changeset
9006** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
9007** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
9008** zeroed and an SQLite error code returned.
9009**
9010** It is the responsibility of the caller to eventually call sqlite3_free()
9011** on the *ppOut pointer to free the buffer allocation following a successful
9012** call to this function.
9013**
9014** WARNING/TODO: This function currently assumes that the input is a valid
9015** changeset. If it is not, the results are undefined.
9016*/
9017int sqlite3changeset_invert(
9018 int nIn, const void *pIn, /* Input changeset */
9019 int *pnOut, void **ppOut /* OUT: Inverse of input */
9020);
9021
9022/*
9023** CAPI3REF: Concatenate Two Changeset Objects
9024**
9025** This function is used to concatenate two changesets, A and B, into a
9026** single changeset. The result is a changeset equivalent to applying
9027** changeset A followed by changeset B.
9028**
9029** This function combines the two input changesets using an
9030** sqlite3_changegroup object. Calling it produces similar results as the
9031** following code fragment:
9032**
9033** sqlite3_changegroup *pGrp;
9034** rc = sqlite3_changegroup_new(&pGrp);
9035** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
9036** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
9037** if( rc==SQLITE_OK ){
9038** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
9039** }else{
9040** *ppOut = 0;
9041** *pnOut = 0;
9042** }
9043**
9044** Refer to the sqlite3_changegroup documentation below for details.
9045*/
9046int sqlite3changeset_concat(
9047 int nA, /* Number of bytes in buffer pA */
9048 void *pA, /* Pointer to buffer containing changeset A */
9049 int nB, /* Number of bytes in buffer pB */
9050 void *pB, /* Pointer to buffer containing changeset B */
9051 int *pnOut, /* OUT: Number of bytes in output changeset */
9052 void **ppOut /* OUT: Buffer containing output changeset */
9053);
9054
9055
9056/*
9057** Changegroup handle.
9058*/
9059typedef struct sqlite3_changegroup sqlite3_changegroup;
9060
9061/*
9062** CAPI3REF: Combine two or more changesets into a single changeset.
9063**
9064** An sqlite3_changegroup object is used to combine two or more changesets
9065** (or patchsets) into a single changeset (or patchset). A single changegroup
9066** object may combine changesets or patchsets, but not both. The output is
9067** always in the same format as the input.
9068**
9069** If successful, this function returns SQLITE_OK and populates (*pp) with
9070** a pointer to a new sqlite3_changegroup object before returning. The caller
9071** should eventually free the returned object using a call to
9072** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
9073** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
9074**
9075** The usual usage pattern for an sqlite3_changegroup object is as follows:
9076**
9077** <ul>
9078** <li> It is created using a call to sqlite3changegroup_new().
9079**
9080** <li> Zero or more changesets (or patchsets) are added to the object
9081** by calling sqlite3changegroup_add().
9082**
9083** <li> The result of combining all input changesets together is obtained
9084** by the application via a call to sqlite3changegroup_output().
9085**
9086** <li> The object is deleted using a call to sqlite3changegroup_delete().
9087** </ul>
9088**
9089** Any number of calls to add() and output() may be made between the calls to
9090** new() and delete(), and in any order.
9091**
9092** As well as the regular sqlite3changegroup_add() and
9093** sqlite3changegroup_output() functions, also available are the streaming
9094** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
9095*/
9096int sqlite3changegroup_new(sqlite3_changegroup **pp);
9097
9098/*
9099** Add all changes within the changeset (or patchset) in buffer pData (size
9100** nData bytes) to the changegroup.
9101**
9102** If the buffer contains a patchset, then all prior calls to this function
9103** on the same changegroup object must also have specified patchsets. Or, if
9104** the buffer contains a changeset, so must have the earlier calls to this
9105** function. Otherwise, SQLITE_ERROR is returned and no changes are added
9106** to the changegroup.
9107**
9108** Rows within the changeset and changegroup are identified by the values in
9109** their PRIMARY KEY columns. A change in the changeset is considered to
9110** apply to the same row as a change already present in the changegroup if
9111** the two rows have the same primary key.
9112**
9113** Changes to rows that that do not already appear in the changegroup are
9114** simply copied into it. Or, if both the new changeset and the changegroup
9115** contain changes that apply to a single row, the final contents of the
9116** changegroup depends on the type of each change, as follows:
9117**
9118** <table border=1 style="margin-left:8ex;margin-right:8ex">
9119** <tr><th style="white-space:pre">Existing Change </th>
9120** <th style="white-space:pre">New Change </th>
9121** <th>Output Change
9122** <tr><td>INSERT <td>INSERT <td>
9123** The new change is ignored. This case does not occur if the new
9124** changeset was recorded immediately after the changesets already
9125** added to the changegroup.
9126** <tr><td>INSERT <td>UPDATE <td>
9127** The INSERT change remains in the changegroup. The values in the
9128** INSERT change are modified as if the row was inserted by the
9129** existing change and then updated according to the new change.
9130** <tr><td>INSERT <td>DELETE <td>
9131** The existing INSERT is removed from the changegroup. The DELETE is
9132** not added.
9133** <tr><td>UPDATE <td>INSERT <td>
9134** The new change is ignored. This case does not occur if the new
9135** changeset was recorded immediately after the changesets already
9136** added to the changegroup.
9137** <tr><td>UPDATE <td>UPDATE <td>
9138** The existing UPDATE remains within the changegroup. It is amended
9139** so that the accompanying values are as if the row was updated once
9140** by the existing change and then again by the new change.
9141** <tr><td>UPDATE <td>DELETE <td>
9142** The existing UPDATE is replaced by the new DELETE within the
9143** changegroup.
9144** <tr><td>DELETE <td>INSERT <td>
9145** If one or more of the column values in the row inserted by the
9146** new change differ from those in the row deleted by the existing
9147** change, the existing DELETE is replaced by an UPDATE within the
9148** changegroup. Otherwise, if the inserted row is exactly the same
9149** as the deleted row, the existing DELETE is simply discarded.
9150** <tr><td>DELETE <td>UPDATE <td>
9151** The new change is ignored. This case does not occur if the new
9152** changeset was recorded immediately after the changesets already
9153** added to the changegroup.
9154** <tr><td>DELETE <td>DELETE <td>
9155** The new change is ignored. This case does not occur if the new
9156** changeset was recorded immediately after the changesets already
9157** added to the changegroup.
9158** </table>
9159**
9160** If the new changeset contains changes to a table that is already present
9161** in the changegroup, then the number of columns and the position of the
9162** primary key columns for the table must be consistent. If this is not the
9163** case, this function fails with SQLITE_SCHEMA. If the input changeset
9164** appears to be corrupt and the corruption is detected, SQLITE_CORRUPT is
9165** returned. Or, if an out-of-memory condition occurs during processing, this
9166** function returns SQLITE_NOMEM. In all cases, if an error occurs the
9167** final contents of the changegroup is undefined.
9168**
9169** If no error occurs, SQLITE_OK is returned.
9170*/
9171int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
9172
9173/*
9174** Obtain a buffer containing a changeset (or patchset) representing the
9175** current contents of the changegroup. If the inputs to the changegroup
9176** were themselves changesets, the output is a changeset. Or, if the
9177** inputs were patchsets, the output is also a patchset.
9178**
9179** As with the output of the sqlite3session_changeset() and
9180** sqlite3session_patchset() functions, all changes related to a single
9181** table are grouped together in the output of this function. Tables appear
9182** in the same order as for the very first changeset added to the changegroup.
9183** If the second or subsequent changesets added to the changegroup contain
9184** changes for tables that do not appear in the first changeset, they are
9185** appended onto the end of the output changeset, again in the order in
9186** which they are first encountered.
9187**
9188** If an error occurs, an SQLite error code is returned and the output
9189** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
9190** is returned and the output variables are set to the size of and a
9191** pointer to the output buffer, respectively. In this case it is the
9192** responsibility of the caller to eventually free the buffer using a
9193** call to sqlite3_free().
9194*/
9195int sqlite3changegroup_output(
9196 sqlite3_changegroup*,
9197 int *pnData, /* OUT: Size of output buffer in bytes */
9198 void **ppData /* OUT: Pointer to output buffer */
9199);
9200
9201/*
9202** Delete a changegroup object.
9203*/
9204void sqlite3changegroup_delete(sqlite3_changegroup*);
9205
9206/*
9207** CAPI3REF: Apply A Changeset To A Database
9208**
9209** Apply a changeset to a database. This function attempts to update the
9210** "main" database attached to handle db with the changes found in the
9211** changeset passed via the second and third arguments.
9212**
9213** The fourth argument (xFilter) passed to this function is the "filter
9214** callback". If it is not NULL, then for each table affected by at least one
9215** change in the changeset, the filter callback is invoked with
9216** the table name as the second argument, and a copy of the context pointer
9217** passed as the sixth argument to this function as the first. If the "filter
9218** callback" returns zero, then no attempt is made to apply any changes to
9219** the table. Otherwise, if the return value is non-zero or the xFilter
9220** argument to this function is NULL, all changes related to the table are
9221** attempted.
9222**
9223** For each table that is not excluded by the filter callback, this function
9224** tests that the target database contains a compatible table. A table is
9225** considered compatible if all of the following are true:
9226**
9227** <ul>
9228** <li> The table has the same name as the name recorded in the
9229** changeset, and
9230** <li> The table has the same number of columns as recorded in the
9231** changeset, and
9232** <li> The table has primary key columns in the same position as
9233** recorded in the changeset.
9234** </ul>
9235**
9236** If there is no compatible table, it is not an error, but none of the
9237** changes associated with the table are applied. A warning message is issued
9238** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
9239** one such warning is issued for each table in the changeset.
9240**
9241** For each change for which there is a compatible table, an attempt is made
9242** to modify the table contents according to the UPDATE, INSERT or DELETE
9243** change. If a change cannot be applied cleanly, the conflict handler
9244** function passed as the fifth argument to sqlite3changeset_apply() may be
9245** invoked. A description of exactly when the conflict handler is invoked for
9246** each type of change is below.
9247**
9248** Unlike the xFilter argument, xConflict may not be passed NULL. The results
9249** of passing anything other than a valid function pointer as the xConflict
9250** argument are undefined.
9251**
9252** Each time the conflict handler function is invoked, it must return one
9253** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
9254** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
9255** if the second argument passed to the conflict handler is either
9256** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
9257** returns an illegal value, any changes already made are rolled back and
9258** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
9259** actions are taken by sqlite3changeset_apply() depending on the value
9260** returned by each invocation of the conflict-handler function. Refer to
9261** the documentation for the three
9262** [SQLITE_CHANGESET_OMIT|available return values] for details.
9263**
9264** <dl>
9265** <dt>DELETE Changes<dd>
9266** For each DELETE change, this function checks if the target database
9267** contains a row with the same primary key value (or values) as the
9268** original row values stored in the changeset. If it does, and the values
9269** stored in all non-primary key columns also match the values stored in
9270** the changeset the row is deleted from the target database.
9271**
9272** If a row with matching primary key values is found, but one or more of
9273** the non-primary key fields contains a value different from the original
9274** row value stored in the changeset, the conflict-handler function is
9275** invoked with [SQLITE_CHANGESET_DATA] as the second argument.
9276**
9277** If no row with matching primary key values is found in the database,
9278** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
9279** passed as the second argument.
9280**
9281** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
9282** (which can only happen if a foreign key constraint is violated), the
9283** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
9284** passed as the second argument. This includes the case where the DELETE
9285** operation is attempted because an earlier call to the conflict handler
9286** function returned [SQLITE_CHANGESET_REPLACE].
9287**
9288** <dt>INSERT Changes<dd>
9289** For each INSERT change, an attempt is made to insert the new row into
9290** the database.
9291**
9292** If the attempt to insert the row fails because the database already
9293** contains a row with the same primary key values, the conflict handler
9294** function is invoked with the second argument set to
9295** [SQLITE_CHANGESET_CONFLICT].
9296**
9297** If the attempt to insert the row fails because of some other constraint
9298** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
9299** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
9300** This includes the case where the INSERT operation is re-attempted because
9301** an earlier call to the conflict handler function returned
9302** [SQLITE_CHANGESET_REPLACE].
9303**
9304** <dt>UPDATE Changes<dd>
9305** For each UPDATE change, this function checks if the target database
9306** contains a row with the same primary key value (or values) as the
9307** original row values stored in the changeset. If it does, and the values
9308** stored in all non-primary key columns also match the values stored in
9309** the changeset the row is updated within the target database.
9310**
9311** If a row with matching primary key values is found, but one or more of
9312** the non-primary key fields contains a value different from an original
9313** row value stored in the changeset, the conflict-handler function is
9314** invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
9315** UPDATE changes only contain values for non-primary key fields that are
9316** to be modified, only those fields need to match the original values to
9317** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
9318**
9319** If no row with matching primary key values is found in the database,
9320** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
9321** passed as the second argument.
9322**
9323** If the UPDATE operation is attempted, but SQLite returns
9324** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
9325** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
9326** This includes the case where the UPDATE operation is attempted after
9327** an earlier call to the conflict handler function returned
9328** [SQLITE_CHANGESET_REPLACE].
9329** </dl>
9330**
9331** It is safe to execute SQL statements, including those that write to the
9332** table that the callback related to, from within the xConflict callback.
9333** This can be used to further customize the applications conflict
9334** resolution strategy.
9335**
9336** All changes made by this function are enclosed in a savepoint transaction.
9337** If any other error (aside from a constraint failure when attempting to
9338** write to the target database) occurs, then the savepoint transaction is
9339** rolled back, restoring the target database to its original state, and an
9340** SQLite error code returned.
9341*/
9342int sqlite3changeset_apply(
9343 sqlite3 *db, /* Apply change to "main" db of this handle */
9344 int nChangeset, /* Size of changeset in bytes */
9345 void *pChangeset, /* Changeset blob */
9346 int(*xFilter)(
9347 void *pCtx, /* Copy of sixth arg to _apply() */
9348 const char *zTab /* Table name */
9349 ),
9350 int(*xConflict)(
9351 void *pCtx, /* Copy of sixth arg to _apply() */
9352 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
9353 sqlite3_changeset_iter *p /* Handle describing change and conflict */
9354 ),
9355 void *pCtx /* First argument passed to xConflict */
9356);
9357
9358/*
9359** CAPI3REF: Constants Passed To The Conflict Handler
9360**
9361** Values that may be passed as the second argument to a conflict-handler.
9362**
9363** <dl>
9364** <dt>SQLITE_CHANGESET_DATA<dd>
9365** The conflict handler is invoked with CHANGESET_DATA as the second argument
9366** when processing a DELETE or UPDATE change if a row with the required
9367** PRIMARY KEY fields is present in the database, but one or more other
9368** (non primary-key) fields modified by the update do not contain the
9369** expected "before" values.
9370**
9371** The conflicting row, in this case, is the database row with the matching
9372** primary key.
9373**
9374** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
9375** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
9376** argument when processing a DELETE or UPDATE change if a row with the
9377** required PRIMARY KEY fields is not present in the database.
9378**
9379** There is no conflicting row in this case. The results of invoking the
9380** sqlite3changeset_conflict() API are undefined.
9381**
9382** <dt>SQLITE_CHANGESET_CONFLICT<dd>
9383** CHANGESET_CONFLICT is passed as the second argument to the conflict
9384** handler while processing an INSERT change if the operation would result
9385** in duplicate primary key values.
9386**
9387** The conflicting row in this case is the database row with the matching
9388** primary key.
9389**
9390** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
9391** If foreign key handling is enabled, and applying a changeset leaves the
9392** database in a state containing foreign key violations, the conflict
9393** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
9394** exactly once before the changeset is committed. If the conflict handler
9395** returns CHANGESET_OMIT, the changes, including those that caused the
9396** foreign key constraint violation, are committed. Or, if it returns
9397** CHANGESET_ABORT, the changeset is rolled back.
9398**
9399** No current or conflicting row information is provided. The only function
9400** it is possible to call on the supplied sqlite3_changeset_iter handle
9401** is sqlite3changeset_fk_conflicts().
9402**
9403** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
9404** If any other constraint violation occurs while applying a change (i.e.
9405** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
9406** invoked with CHANGESET_CONSTRAINT as the second argument.
9407**
9408** There is no conflicting row in this case. The results of invoking the
9409** sqlite3changeset_conflict() API are undefined.
9410**
9411** </dl>
9412*/
9413#define SQLITE_CHANGESET_DATA 1
9414#define SQLITE_CHANGESET_NOTFOUND 2
9415#define SQLITE_CHANGESET_CONFLICT 3
9416#define SQLITE_CHANGESET_CONSTRAINT 4
9417#define SQLITE_CHANGESET_FOREIGN_KEY 5
9418
9419/*
9420** CAPI3REF: Constants Returned By The Conflict Handler
9421**
9422** A conflict handler callback must return one of the following three values.
9423**
9424** <dl>
9425** <dt>SQLITE_CHANGESET_OMIT<dd>
9426** If a conflict handler returns this value no special action is taken. The
9427** change that caused the conflict is not applied. The session module
9428** continues to the next change in the changeset.
9429**
9430** <dt>SQLITE_CHANGESET_REPLACE<dd>
9431** This value may only be returned if the second argument to the conflict
9432** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
9433** is not the case, any changes applied so far are rolled back and the
9434** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
9435**
9436** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
9437** handler, then the conflicting row is either updated or deleted, depending
9438** on the type of change.
9439**
9440** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
9441** handler, then the conflicting row is removed from the database and a
9442** second attempt to apply the change is made. If this second attempt fails,
9443** the original row is restored to the database before continuing.
9444**
9445** <dt>SQLITE_CHANGESET_ABORT<dd>
9446** If this value is returned, any changes applied so far are rolled back
9447** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
9448** </dl>
9449*/
9450#define SQLITE_CHANGESET_OMIT 0
9451#define SQLITE_CHANGESET_REPLACE 1
9452#define SQLITE_CHANGESET_ABORT 2
9453
9454/*
9455** CAPI3REF: Streaming Versions of API functions.
9456**
9457** The six streaming API xxx_strm() functions serve similar purposes to the
9458** corresponding non-streaming API functions:
9459**
9460** <table border=1 style="margin-left:8ex;margin-right:8ex">
9461** <tr><th>Streaming function<th>Non-streaming equivalent</th>
9462** <tr><td>sqlite3changeset_apply_str<td>[sqlite3changeset_apply]
9463** <tr><td>sqlite3changeset_concat_str<td>[sqlite3changeset_concat]
9464** <tr><td>sqlite3changeset_invert_str<td>[sqlite3changeset_invert]
9465** <tr><td>sqlite3changeset_start_str<td>[sqlite3changeset_start]
9466** <tr><td>sqlite3session_changeset_str<td>[sqlite3session_changeset]
9467** <tr><td>sqlite3session_patchset_str<td>[sqlite3session_patchset]
9468** </table>
9469**
9470** Non-streaming functions that accept changesets (or patchsets) as input
9471** require that the entire changeset be stored in a single buffer in memory.
9472** Similarly, those that return a changeset or patchset do so by returning
9473** a pointer to a single large buffer allocated using sqlite3_malloc().
9474** Normally this is convenient. However, if an application running in a
9475** low-memory environment is required to handle very large changesets, the
9476** large contiguous memory allocations required can become onerous.
9477**
9478** In order to avoid this problem, instead of a single large buffer, input
9479** is passed to a streaming API functions by way of a callback function that
9480** the sessions module invokes to incrementally request input data as it is
9481** required. In all cases, a pair of API function parameters such as
9482**
9483** <pre>
9484** int nChangeset,
9485** void *pChangeset,
9486** </pre>
9487**
9488** Is replaced by:
9489**
9490** <pre>
9491** int (*xInput)(void *pIn, void *pData, int *pnData),
9492** void *pIn,
9493** </pre>
9494**
9495** Each time the xInput callback is invoked by the sessions module, the first
9496** argument passed is a copy of the supplied pIn context pointer. The second
9497** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
9498** error occurs the xInput method should copy up to (*pnData) bytes of data
9499** into the buffer and set (*pnData) to the actual number of bytes copied
9500** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
9501** should be set to zero to indicate this. Or, if an error occurs, an SQLite
9502** error code should be returned. In all cases, if an xInput callback returns
9503** an error, all processing is abandoned and the streaming API function
9504** returns a copy of the error code to the caller.
9505**
9506** In the case of sqlite3changeset_start_strm(), the xInput callback may be
9507** invoked by the sessions module at any point during the lifetime of the
9508** iterator. If such an xInput callback returns an error, the iterator enters
9509** an error state, whereby all subsequent calls to iterator functions
9510** immediately fail with the same error code as returned by xInput.
9511**
9512** Similarly, streaming API functions that return changesets (or patchsets)
9513** return them in chunks by way of a callback function instead of via a
9514** pointer to a single large buffer. In this case, a pair of parameters such
9515** as:
9516**
9517** <pre>
9518** int *pnChangeset,
9519** void **ppChangeset,
9520** </pre>
9521**
9522** Is replaced by:
9523**
9524** <pre>
9525** int (*xOutput)(void *pOut, const void *pData, int nData),
9526** void *pOut
9527** </pre>
9528**
9529** The xOutput callback is invoked zero or more times to return data to
9530** the application. The first parameter passed to each call is a copy of the
9531** pOut pointer supplied by the application. The second parameter, pData,
9532** points to a buffer nData bytes in size containing the chunk of output
9533** data being returned. If the xOutput callback successfully processes the
9534** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
9535** it should return some other SQLite error code. In this case processing
9536** is immediately abandoned and the streaming API function returns a copy
9537** of the xOutput error code to the application.
9538**
9539** The sessions module never invokes an xOutput callback with the third
9540** parameter set to a value less than or equal to zero. Other than this,
9541** no guarantees are made as to the size of the chunks of data returned.
9542*/
9543int sqlite3changeset_apply_strm(
9544 sqlite3 *db, /* Apply change to "main" db of this handle */
9545 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
9546 void *pIn, /* First arg for xInput */
9547 int(*xFilter)(
9548 void *pCtx, /* Copy of sixth arg to _apply() */
9549 const char *zTab /* Table name */
9550 ),
9551 int(*xConflict)(
9552 void *pCtx, /* Copy of sixth arg to _apply() */
9553 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
9554 sqlite3_changeset_iter *p /* Handle describing change and conflict */
9555 ),
9556 void *pCtx /* First argument passed to xConflict */
9557);
9558int sqlite3changeset_concat_strm(
9559 int (*xInputA)(void *pIn, void *pData, int *pnData),
9560 void *pInA,
9561 int (*xInputB)(void *pIn, void *pData, int *pnData),
9562 void *pInB,
9563 int (*xOutput)(void *pOut, const void *pData, int nData),
9564 void *pOut
9565);
9566int sqlite3changeset_invert_strm(
9567 int (*xInput)(void *pIn, void *pData, int *pnData),
9568 void *pIn,
9569 int (*xOutput)(void *pOut, const void *pData, int nData),
9570 void *pOut
9571);
9572int sqlite3changeset_start_strm(
9573 sqlite3_changeset_iter **pp,
9574 int (*xInput)(void *pIn, void *pData, int *pnData),
9575 void *pIn
9576);
9577int sqlite3session_changeset_strm(
9578 sqlite3_session *pSession,
9579 int (*xOutput)(void *pOut, const void *pData, int nData),
9580 void *pOut
9581);
9582int sqlite3session_patchset_strm(
9583 sqlite3_session *pSession,
9584 int (*xOutput)(void *pOut, const void *pData, int nData),
9585 void *pOut
9586);
9587int sqlite3changegroup_add_strm(sqlite3_changegroup*,
9588 int (*xInput)(void *pIn, void *pData, int *pnData),
9589 void *pIn
9590);
9591int sqlite3changegroup_output_strm(sqlite3_changegroup*,
9592 int (*xOutput)(void *pOut, const void *pData, int nData),
9593 void *pOut
9594);
9595
9596
9597/*
9598** Make sure we can call this stuff from C++.
9599*/
9600#ifdef __cplusplus
9601}
9602#endif
9603
9604#endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
9605
9606/******** End of sqlite3session.h *********/
9607/******** Begin file fts5.h *********/
9608/*
9609** 2014 May 31
9610**
9611** The author disclaims copyright to this source code. In place of
9612** a legal notice, here is a blessing:
9613**
9614** May you do good and not evil.
9615** May you find forgiveness for yourself and forgive others.
9616** May you share freely, never taking more than you give.
9617**
9618******************************************************************************
9619**
9620** Interfaces to extend FTS5. Using the interfaces defined in this file,
9621** FTS5 may be extended with:
9622**
9623** * custom tokenizers, and
9624** * custom auxiliary functions.
9625*/
9626
9627
9628#ifndef _FTS5_H
9629#define _FTS5_H
9630
9631
9632#ifdef __cplusplus
9633extern "C" {
9634#endif
9635
9636/*************************************************************************
9637** CUSTOM AUXILIARY FUNCTIONS
9638**
9639** Virtual table implementations may overload SQL functions by implementing
9640** the sqlite3_module.xFindFunction() method.
9641*/
9642
9643typedef struct Fts5ExtensionApi Fts5ExtensionApi;
9644typedef struct Fts5Context Fts5Context;
9645typedef struct Fts5PhraseIter Fts5PhraseIter;
9646
9647typedef void (*fts5_extension_function)(
9648 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
9649 Fts5Context *pFts, /* First arg to pass to pApi functions */
9650 sqlite3_context *pCtx, /* Context for returning result/error */
9651 int nVal, /* Number of values in apVal[] array */
9652 sqlite3_value **apVal /* Array of trailing arguments */
9653);
9654
9655struct Fts5PhraseIter {
9656 const unsigned char *a;
9657 const unsigned char *b;
9658};
9659
9660/*
9661** EXTENSION API FUNCTIONS
9662**
9663** xUserData(pFts):
9664** Return a copy of the context pointer the extension function was
9665** registered with.
9666**
9667** xColumnTotalSize(pFts, iCol, pnToken):
9668** If parameter iCol is less than zero, set output variable *pnToken
9669** to the total number of tokens in the FTS5 table. Or, if iCol is
9670** non-negative but less than the number of columns in the table, return
9671** the total number of tokens in column iCol, considering all rows in
9672** the FTS5 table.
9673**
9674** If parameter iCol is greater than or equal to the number of columns
9675** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
9676** an OOM condition or IO error), an appropriate SQLite error code is
9677** returned.
9678**
9679** xColumnCount(pFts):
9680** Return the number of columns in the table.
9681**
9682** xColumnSize(pFts, iCol, pnToken):
9683** If parameter iCol is less than zero, set output variable *pnToken
9684** to the total number of tokens in the current row. Or, if iCol is
9685** non-negative but less than the number of columns in the table, set
9686** *pnToken to the number of tokens in column iCol of the current row.
9687**
9688** If parameter iCol is greater than or equal to the number of columns
9689** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
9690** an OOM condition or IO error), an appropriate SQLite error code is
9691** returned.
9692**
9693** This function may be quite inefficient if used with an FTS5 table
9694** created with the "columnsize=0" option.
9695**
9696** xColumnText:
9697** This function attempts to retrieve the text of column iCol of the
9698** current document. If successful, (*pz) is set to point to a buffer
9699** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
9700** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
9701** if an error occurs, an SQLite error code is returned and the final values
9702** of (*pz) and (*pn) are undefined.
9703**
9704** xPhraseCount:
9705** Returns the number of phrases in the current query expression.
9706**
9707** xPhraseSize:
9708** Returns the number of tokens in phrase iPhrase of the query. Phrases
9709** are numbered starting from zero.
9710**
9711** xInstCount:
9712** Set *pnInst to the total number of occurrences of all phrases within
9713** the query within the current row. Return SQLITE_OK if successful, or
9714** an error code (i.e. SQLITE_NOMEM) if an error occurs.
9715**
9716** This API can be quite slow if used with an FTS5 table created with the
9717** "detail=none" or "detail=column" option. If the FTS5 table is created
9718** with either "detail=none" or "detail=column" and "content=" option
9719** (i.e. if it is a contentless table), then this API always returns 0.
9720**
9721** xInst:
9722** Query for the details of phrase match iIdx within the current row.
9723** Phrase matches are numbered starting from zero, so the iIdx argument
9724** should be greater than or equal to zero and smaller than the value
9725** output by xInstCount().
9726**
9727** Usually, output parameter *piPhrase is set to the phrase number, *piCol
9728** to the column in which it occurs and *piOff the token offset of the
9729** first token of the phrase. The exception is if the table was created
9730** with the offsets=0 option specified. In this case *piOff is always
9731** set to -1.
9732**
9733** Returns SQLITE_OK if successful, or an error code (i.e. SQLITE_NOMEM)
9734** if an error occurs.
9735**
9736** This API can be quite slow if used with an FTS5 table created with the
9737** "detail=none" or "detail=column" option.
9738**
9739** xRowid:
9740** Returns the rowid of the current row.
9741**
9742** xTokenize:
9743** Tokenize text using the tokenizer belonging to the FTS5 table.
9744**
9745** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
9746** This API function is used to query the FTS table for phrase iPhrase
9747** of the current query. Specifically, a query equivalent to:
9748**
9749** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
9750**
9751** with $p set to a phrase equivalent to the phrase iPhrase of the
9752** current query is executed. Any column filter that applies to
9753** phrase iPhrase of the current query is included in $p. For each
9754** row visited, the callback function passed as the fourth argument
9755** is invoked. The context and API objects passed to the callback
9756** function may be used to access the properties of each matched row.
9757** Invoking Api.xUserData() returns a copy of the pointer passed as
9758** the third argument to pUserData.
9759**
9760** If the callback function returns any value other than SQLITE_OK, the
9761** query is abandoned and the xQueryPhrase function returns immediately.
9762** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
9763** Otherwise, the error code is propagated upwards.
9764**
9765** If the query runs to completion without incident, SQLITE_OK is returned.
9766** Or, if some error occurs before the query completes or is aborted by
9767** the callback, an SQLite error code is returned.
9768**
9769**
9770** xSetAuxdata(pFts5, pAux, xDelete)
9771**
9772** Save the pointer passed as the second argument as the extension functions
9773** "auxiliary data". The pointer may then be retrieved by the current or any
9774** future invocation of the same fts5 extension function made as part of
9775** of the same MATCH query using the xGetAuxdata() API.
9776**
9777** Each extension function is allocated a single auxiliary data slot for
9778** each FTS query (MATCH expression). If the extension function is invoked
9779** more than once for a single FTS query, then all invocations share a
9780** single auxiliary data context.
9781**
9782** If there is already an auxiliary data pointer when this function is
9783** invoked, then it is replaced by the new pointer. If an xDelete callback
9784** was specified along with the original pointer, it is invoked at this
9785** point.
9786**
9787** The xDelete callback, if one is specified, is also invoked on the
9788** auxiliary data pointer after the FTS5 query has finished.
9789**
9790** If an error (e.g. an OOM condition) occurs within this function, an
9791** the auxiliary data is set to NULL and an error code returned. If the
9792** xDelete parameter was not NULL, it is invoked on the auxiliary data
9793** pointer before returning.
9794**
9795**
9796** xGetAuxdata(pFts5, bClear)
9797**
9798** Returns the current auxiliary data pointer for the fts5 extension
9799** function. See the xSetAuxdata() method for details.
9800**
9801** If the bClear argument is non-zero, then the auxiliary data is cleared
9802** (set to NULL) before this function returns. In this case the xDelete,
9803** if any, is not invoked.
9804**
9805**
9806** xRowCount(pFts5, pnRow)
9807**
9808** This function is used to retrieve the total number of rows in the table.
9809** In other words, the same value that would be returned by:
9810**
9811** SELECT count(*) FROM ftstable;
9812**
9813** xPhraseFirst()
9814** This function is used, along with type Fts5PhraseIter and the xPhraseNext
9815** method, to iterate through all instances of a single query phrase within
9816** the current row. This is the same information as is accessible via the
9817** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
9818** to use, this API may be faster under some circumstances. To iterate
9819** through instances of phrase iPhrase, use the following code:
9820**
9821** Fts5PhraseIter iter;
9822** int iCol, iOff;
9823** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
9824** iCol>=0;
9825** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
9826** ){
9827** // An instance of phrase iPhrase at offset iOff of column iCol
9828** }
9829**
9830** The Fts5PhraseIter structure is defined above. Applications should not
9831** modify this structure directly - it should only be used as shown above
9832** with the xPhraseFirst() and xPhraseNext() API methods (and by
9833** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
9834**
9835** This API can be quite slow if used with an FTS5 table created with the
9836** "detail=none" or "detail=column" option. If the FTS5 table is created
9837** with either "detail=none" or "detail=column" and "content=" option
9838** (i.e. if it is a contentless table), then this API always iterates
9839** through an empty set (all calls to xPhraseFirst() set iCol to -1).
9840**
9841** xPhraseNext()
9842** See xPhraseFirst above.
9843**
9844** xPhraseFirstColumn()
9845** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
9846** and xPhraseNext() APIs described above. The difference is that instead
9847** of iterating through all instances of a phrase in the current row, these
9848** APIs are used to iterate through the set of columns in the current row
9849** that contain one or more instances of a specified phrase. For example:
9850**
9851** Fts5PhraseIter iter;
9852** int iCol;
9853** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
9854** iCol>=0;
9855** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
9856** ){
9857** // Column iCol contains at least one instance of phrase iPhrase
9858** }
9859**
9860** This API can be quite slow if used with an FTS5 table created with the
9861** "detail=none" option. If the FTS5 table is created with either
9862** "detail=none" "content=" option (i.e. if it is a contentless table),
9863** then this API always iterates through an empty set (all calls to
9864** xPhraseFirstColumn() set iCol to -1).
9865**
9866** The information accessed using this API and its companion
9867** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
9868** (or xInst/xInstCount). The chief advantage of this API is that it is
9869** significantly more efficient than those alternatives when used with
9870** "detail=column" tables.
9871**
9872** xPhraseNextColumn()
9873** See xPhraseFirstColumn above.
9874*/
9875struct Fts5ExtensionApi {
9876 int iVersion; /* Currently always set to 3 */
9877
9878 void *(*xUserData)(Fts5Context*);
9879
9880 int (*xColumnCount)(Fts5Context*);
9881 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
9882 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
9883
9884 int (*xTokenize)(Fts5Context*,
9885 const char *pText, int nText, /* Text to tokenize */
9886 void *pCtx, /* Context passed to xToken() */
9887 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
9888 );
9889
9890 int (*xPhraseCount)(Fts5Context*);
9891 int (*xPhraseSize)(Fts5Context*, int iPhrase);
9892
9893 int (*xInstCount)(Fts5Context*, int *pnInst);
9894 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
9895
9896 sqlite3_int64 (*xRowid)(Fts5Context*);
9897 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
9898 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
9899
9900 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
9901 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
9902 );
9903 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
9904 void *(*xGetAuxdata)(Fts5Context*, int bClear);
9905
9906 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
9907 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
9908
9909 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
9910 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
9911};
9912
9913/*
9914** CUSTOM AUXILIARY FUNCTIONS
9915*************************************************************************/
9916
9917/*************************************************************************
9918** CUSTOM TOKENIZERS
9919**
9920** Applications may also register custom tokenizer types. A tokenizer
9921** is registered by providing fts5 with a populated instance of the
9922** following structure. All structure methods must be defined, setting
9923** any member of the fts5_tokenizer struct to NULL leads to undefined
9924** behaviour. The structure methods are expected to function as follows:
9925**
9926** xCreate:
9927** This function is used to allocate and inititalize a tokenizer instance.
9928** A tokenizer instance is required to actually tokenize text.
9929**
9930** The first argument passed to this function is a copy of the (void*)
9931** pointer provided by the application when the fts5_tokenizer object
9932** was registered with FTS5 (the third argument to xCreateTokenizer()).
9933** The second and third arguments are an array of nul-terminated strings
9934** containing the tokenizer arguments, if any, specified following the
9935** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
9936** to create the FTS5 table.
9937**
9938** The final argument is an output variable. If successful, (*ppOut)
9939** should be set to point to the new tokenizer handle and SQLITE_OK
9940** returned. If an error occurs, some value other than SQLITE_OK should
9941** be returned. In this case, fts5 assumes that the final value of *ppOut
9942** is undefined.
9943**
9944** xDelete:
9945** This function is invoked to delete a tokenizer handle previously
9946** allocated using xCreate(). Fts5 guarantees that this function will
9947** be invoked exactly once for each successful call to xCreate().
9948**
9949** xTokenize:
9950** This function is expected to tokenize the nText byte string indicated
9951** by argument pText. pText may or may not be nul-terminated. The first
9952** argument passed to this function is a pointer to an Fts5Tokenizer object
9953** returned by an earlier call to xCreate().
9954**
9955** The second argument indicates the reason that FTS5 is requesting
9956** tokenization of the supplied text. This is always one of the following
9957** four values:
9958**
9959** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
9960** or removed from the FTS table. The tokenizer is being invoked to
9961** determine the set of tokens to add to (or delete from) the
9962** FTS index.
9963**
9964** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
9965** against the FTS index. The tokenizer is being called to tokenize
9966** a bareword or quoted string specified as part of the query.
9967**
9968** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
9969** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
9970** followed by a "*" character, indicating that the last token
9971** returned by the tokenizer will be treated as a token prefix.
9972**
9973** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
9974** satisfy an fts5_api.xTokenize() request made by an auxiliary
9975** function. Or an fts5_api.xColumnSize() request made by the same
9976** on a columnsize=0 database.
9977** </ul>
9978**
9979** For each token in the input string, the supplied callback xToken() must
9980** be invoked. The first argument to it should be a copy of the pointer
9981** passed as the second argument to xTokenize(). The third and fourth
9982** arguments are a pointer to a buffer containing the token text, and the
9983** size of the token in bytes. The 4th and 5th arguments are the byte offsets
9984** of the first byte of and first byte immediately following the text from
9985** which the token is derived within the input.
9986**
9987** The second argument passed to the xToken() callback ("tflags") should
9988** normally be set to 0. The exception is if the tokenizer supports
9989** synonyms. In this case see the discussion below for details.
9990**
9991** FTS5 assumes the xToken() callback is invoked for each token in the
9992** order that they occur within the input text.
9993**
9994** If an xToken() callback returns any value other than SQLITE_OK, then
9995** the tokenization should be abandoned and the xTokenize() method should
9996** immediately return a copy of the xToken() return value. Or, if the
9997** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
9998** if an error occurs with the xTokenize() implementation itself, it
9999** may abandon the tokenization and return any error code other than
10000** SQLITE_OK or SQLITE_DONE.
10001**
10002** SYNONYM SUPPORT
10003**
10004** Custom tokenizers may also support synonyms. Consider a case in which a
10005** user wishes to query for a phrase such as "first place". Using the
10006** built-in tokenizers, the FTS5 query 'first + place' will match instances
10007** of "first place" within the document set, but not alternative forms
10008** such as "1st place". In some applications, it would be better to match
10009** all instances of "first place" or "1st place" regardless of which form
10010** the user specified in the MATCH query text.
10011**
10012** There are several ways to approach this in FTS5:
10013**
10014** <ol><li> By mapping all synonyms to a single token. In this case, the
10015** In the above example, this means that the tokenizer returns the
10016** same token for inputs "first" and "1st". Say that token is in
10017** fact "first", so that when the user inserts the document "I won
10018** 1st place" entries are added to the index for tokens "i", "won",
10019** "first" and "place". If the user then queries for '1st + place',
10020** the tokenizer substitutes "first" for "1st" and the query works
10021** as expected.
10022**
10023** <li> By adding multiple synonyms for a single term to the FTS index.
10024** In this case, when tokenizing query text, the tokenizer may
10025** provide multiple synonyms for a single term within the document.
10026** FTS5 then queries the index for each synonym individually. For
10027** example, faced with the query:
10028**
10029** <codeblock>
10030** ... MATCH 'first place'</codeblock>
10031**
10032** the tokenizer offers both "1st" and "first" as synonyms for the
10033** first token in the MATCH query and FTS5 effectively runs a query
10034** similar to:
10035**
10036** <codeblock>
10037** ... MATCH '(first OR 1st) place'</codeblock>
10038**
10039** except that, for the purposes of auxiliary functions, the query
10040** still appears to contain just two phrases - "(first OR 1st)"
10041** being treated as a single phrase.
10042**
10043** <li> By adding multiple synonyms for a single term to the FTS index.
10044** Using this method, when tokenizing document text, the tokenizer
10045** provides multiple synonyms for each token. So that when a
10046** document such as "I won first place" is tokenized, entries are
10047** added to the FTS index for "i", "won", "first", "1st" and
10048** "place".
10049**
10050** This way, even if the tokenizer does not provide synonyms
10051** when tokenizing query text (it should not - to do would be
10052** inefficient), it doesn't matter if the user queries for
10053** 'first + place' or '1st + place', as there are entires in the
10054** FTS index corresponding to both forms of the first token.
10055** </ol>
10056**
10057** Whether it is parsing document or query text, any call to xToken that
10058** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
10059** is considered to supply a synonym for the previous token. For example,
10060** when parsing the document "I won first place", a tokenizer that supports
10061** synonyms would call xToken() 5 times, as follows:
10062**
10063** <codeblock>
10064** xToken(pCtx, 0, "i", 1, 0, 1);
10065** xToken(pCtx, 0, "won", 3, 2, 5);
10066** xToken(pCtx, 0, "first", 5, 6, 11);
10067** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
10068** xToken(pCtx, 0, "place", 5, 12, 17);
10069**</codeblock>
10070**
10071** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
10072** xToken() is called. Multiple synonyms may be specified for a single token
10073** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
10074** There is no limit to the number of synonyms that may be provided for a
10075** single token.
10076**
10077** In many cases, method (1) above is the best approach. It does not add
10078** extra data to the FTS index or require FTS5 to query for multiple terms,
10079** so it is efficient in terms of disk space and query speed. However, it
10080** does not support prefix queries very well. If, as suggested above, the
10081** token "first" is subsituted for "1st" by the tokenizer, then the query:
10082**
10083** <codeblock>
10084** ... MATCH '1s*'</codeblock>
10085**
10086** will not match documents that contain the token "1st" (as the tokenizer
10087** will probably not map "1s" to any prefix of "first").
10088**
10089** For full prefix support, method (3) may be preferred. In this case,
10090** because the index contains entries for both "first" and "1st", prefix
10091** queries such as 'fi*' or '1s*' will match correctly. However, because
10092** extra entries are added to the FTS index, this method uses more space
10093** within the database.
10094**
10095** Method (2) offers a midpoint between (1) and (3). Using this method,
10096** a query such as '1s*' will match documents that contain the literal
10097** token "1st", but not "first" (assuming the tokenizer is not able to
10098** provide synonyms for prefixes). However, a non-prefix query like '1st'
10099** will match against "1st" and "first". This method does not require
10100** extra disk space, as no extra entries are added to the FTS index.
10101** On the other hand, it may require more CPU cycles to run MATCH queries,
10102** as separate queries of the FTS index are required for each synonym.
10103**
10104** When using methods (2) or (3), it is important that the tokenizer only
10105** provide synonyms when tokenizing document text (method (2)) or query
10106** text (method (3)), not both. Doing so will not cause any errors, but is
10107** inefficient.
10108*/
10109typedef struct Fts5Tokenizer Fts5Tokenizer;
10110typedef struct fts5_tokenizer fts5_tokenizer;
10111struct fts5_tokenizer {
10112 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
10113 void (*xDelete)(Fts5Tokenizer*);
10114 int (*xTokenize)(Fts5Tokenizer*,
10115 void *pCtx,
10116 int flags, /* Mask of FTS5_TOKENIZE_* flags */
10117 const char *pText, int nText,
10118 int (*xToken)(
10119 void *pCtx, /* Copy of 2nd argument to xTokenize() */
10120 int tflags, /* Mask of FTS5_TOKEN_* flags */
10121 const char *pToken, /* Pointer to buffer containing token */
10122 int nToken, /* Size of token in bytes */
10123 int iStart, /* Byte offset of token within input text */
10124 int iEnd /* Byte offset of end of token within input text */
10125 )
10126 );
10127};
10128
10129/* Flags that may be passed as the third argument to xTokenize() */
10130#define FTS5_TOKENIZE_QUERY 0x0001
10131#define FTS5_TOKENIZE_PREFIX 0x0002
10132#define FTS5_TOKENIZE_DOCUMENT 0x0004
10133#define FTS5_TOKENIZE_AUX 0x0008
10134
10135/* Flags that may be passed by the tokenizer implementation back to FTS5
10136** as the third argument to the supplied xToken callback. */
10137#define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
10138
10139/*
10140** END OF CUSTOM TOKENIZERS
10141*************************************************************************/
10142
10143/*************************************************************************
10144** FTS5 EXTENSION REGISTRATION API
10145*/
10146typedef struct fts5_api fts5_api;
10147struct fts5_api {
10148 int iVersion; /* Currently always set to 2 */
10149
10150 /* Create a new tokenizer */
10151 int (*xCreateTokenizer)(
10152 fts5_api *pApi,
10153 const char *zName,
10154 void *pContext,
10155 fts5_tokenizer *pTokenizer,
10156 void (*xDestroy)(void*)
10157 );
10158
10159 /* Find an existing tokenizer */
10160 int (*xFindTokenizer)(
10161 fts5_api *pApi,
10162 const char *zName,
10163 void **ppContext,
10164 fts5_tokenizer *pTokenizer
10165 );
10166
10167 /* Create a new auxiliary function */
10168 int (*xCreateFunction)(
10169 fts5_api *pApi,
10170 const char *zName,
10171 void *pContext,
10172 fts5_extension_function xFunction,
10173 void (*xDestroy)(void*)
10174 );
10175};
10176
10177/*
10178** END OF REGISTRATION API
10179*************************************************************************/
10180
10181#ifdef __cplusplus
10182} /* end of the 'extern "C"' block */
10183#endif
10184
10185#endif /* _FTS5_H */
10186
10187
10188/******** End of fts5.h *********/