xref: /sqlite-3.40.0/src/sqlite.h.in (revision a408adc5)
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.
14**
15** @(#) $Id: sqlite.h.in,v 1.209 2007/05/15 02:45:19 drh Exp $
16*/
17#ifndef _SQLITE3_H_
18#define _SQLITE3_H_
19#include <stdarg.h>     /* Needed for the definition of va_list */
20
21/*
22** Make sure we can call this stuff from C++.
23*/
24#ifdef __cplusplus
25extern "C" {
26#endif
27
28/*
29** The version of the SQLite library.
30*/
31#ifdef SQLITE_VERSION
32# undef SQLITE_VERSION
33#endif
34#define SQLITE_VERSION         "--VERS--"
35
36/*
37** The format of the version string is "X.Y.Z<trailing string>", where
38** X is the major version number, Y is the minor version number and Z
39** is the release number. The trailing string is often "alpha" or "beta".
40** For example "3.1.1beta".
41**
42** The SQLITE_VERSION_NUMBER is an integer with the value
43** (X*100000 + Y*1000 + Z). For example, for version "3.1.1beta",
44** SQLITE_VERSION_NUMBER is set to 3001001. To detect if they are using
45** version 3.1.1 or greater at compile time, programs may use the test
46** (SQLITE_VERSION_NUMBER>=3001001).
47*/
48#ifdef SQLITE_VERSION_NUMBER
49# undef SQLITE_VERSION_NUMBER
50#endif
51#define SQLITE_VERSION_NUMBER --VERSION-NUMBER--
52
53/*
54** The version string is also compiled into the library so that a program
55** can check to make sure that the lib*.a file and the *.h file are from
56** the same version.  The sqlite3_libversion() function returns a pointer
57** to the sqlite3_version variable - useful in DLLs which cannot access
58** global variables.
59*/
60extern const char sqlite3_version[];
61const char *sqlite3_libversion(void);
62
63/*
64** Return the value of the SQLITE_VERSION_NUMBER macro when the
65** library was compiled.
66*/
67int sqlite3_libversion_number(void);
68
69/*
70** Each open sqlite database is represented by an instance of the
71** following opaque structure.
72*/
73typedef struct sqlite3 sqlite3;
74
75
76/*
77** Some compilers do not support the "long long" datatype.  So we have
78** to do a typedef that for 64-bit integers that depends on what compiler
79** is being used.
80*/
81#ifdef SQLITE_INT64_TYPE
82  typedef SQLITE_INT64_TYPE sqlite_int64;
83  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
84#elif defined(_MSC_VER) || defined(__BORLANDC__)
85  typedef __int64 sqlite_int64;
86  typedef unsigned __int64 sqlite_uint64;
87#else
88  typedef long long int sqlite_int64;
89  typedef unsigned long long int sqlite_uint64;
90#endif
91
92/*
93** If compiling for a processor that lacks floating point support,
94** substitute integer for floating-point
95*/
96#ifdef SQLITE_OMIT_FLOATING_POINT
97# define double sqlite_int64
98#endif
99
100/*
101** A function to close the database.
102**
103** Call this function with a pointer to a structure that was previously
104** returned from sqlite3_open() and the corresponding database will by closed.
105**
106** All SQL statements prepared using sqlite3_prepare() or
107** sqlite3_prepare16() must be deallocated using sqlite3_finalize() before
108** this routine is called. Otherwise, SQLITE_BUSY is returned and the
109** database connection remains open.
110*/
111int sqlite3_close(sqlite3 *);
112
113/*
114** The type for a callback function.
115*/
116typedef int (*sqlite3_callback)(void*,int,char**, char**);
117
118/*
119** A function to executes one or more statements of SQL.
120**
121** If one or more of the SQL statements are queries, then
122** the callback function specified by the 3rd parameter is
123** invoked once for each row of the query result.  This callback
124** should normally return 0.  If the callback returns a non-zero
125** value then the query is aborted, all subsequent SQL statements
126** are skipped and the sqlite3_exec() function returns the SQLITE_ABORT.
127**
128** The 1st parameter is an arbitrary pointer that is passed
129** to the callback function as its first parameter.
130**
131** The 2nd parameter to the callback function is the number of
132** columns in the query result.  The 3rd parameter to the callback
133** is an array of strings holding the values for each column.
134** The 4th parameter to the callback is an array of strings holding
135** the names of each column.
136**
137** The callback function may be NULL, even for queries.  A NULL
138** callback is not an error.  It just means that no callback
139** will be invoked.
140**
141** If an error occurs while parsing or evaluating the SQL (but
142** not while executing the callback) then an appropriate error
143** message is written into memory obtained from malloc() and
144** *errmsg is made to point to that message.  The calling function
145** is responsible for freeing the memory that holds the error
146** message.   Use sqlite3_free() for this.  If errmsg==NULL,
147** then no error message is ever written.
148**
149** The return value is is SQLITE_OK if there are no errors and
150** some other return code if there is an error.  The particular
151** return value depends on the type of error.
152**
153** If the query could not be executed because a database file is
154** locked or busy, then this function returns SQLITE_BUSY.  (This
155** behavior can be modified somewhat using the sqlite3_busy_handler()
156** and sqlite3_busy_timeout() functions below.)
157*/
158int sqlite3_exec(
159  sqlite3*,                     /* An open database */
160  const char *sql,              /* SQL to be executed */
161  sqlite3_callback,             /* Callback function */
162  void *,                       /* 1st argument to callback function */
163  char **errmsg                 /* Error msg written here */
164);
165
166/*
167** Return values for sqlite3_exec() and sqlite3_step()
168*/
169#define SQLITE_OK           0   /* Successful result */
170/* beginning-of-error-codes */
171#define SQLITE_ERROR        1   /* SQL error or missing database */
172#define SQLITE_INTERNAL     2   /* NOT USED. Internal logic error in SQLite */
173#define SQLITE_PERM         3   /* Access permission denied */
174#define SQLITE_ABORT        4   /* Callback routine requested an abort */
175#define SQLITE_BUSY         5   /* The database file is locked */
176#define SQLITE_LOCKED       6   /* A table in the database is locked */
177#define SQLITE_NOMEM        7   /* A malloc() failed */
178#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
179#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
180#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
181#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
182#define SQLITE_NOTFOUND    12   /* NOT USED. Table or record not found */
183#define SQLITE_FULL        13   /* Insertion failed because database is full */
184#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
185#define SQLITE_PROTOCOL    15   /* NOT USED. Database lock protocol error */
186#define SQLITE_EMPTY       16   /* Database is empty */
187#define SQLITE_SCHEMA      17   /* The database schema changed */
188#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
189#define SQLITE_CONSTRAINT  19   /* Abort due to contraint violation */
190#define SQLITE_MISMATCH    20   /* Data type mismatch */
191#define SQLITE_MISUSE      21   /* Library used incorrectly */
192#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
193#define SQLITE_AUTH        23   /* Authorization denied */
194#define SQLITE_FORMAT      24   /* Auxiliary database format error */
195#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
196#define SQLITE_NOTADB      26   /* File opened that is not a database file */
197#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
198#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
199/* end-of-error-codes */
200
201/*
202** Using the sqlite3_extended_result_codes() API, you can cause
203** SQLite to return result codes with additional information in
204** their upper bits.  The lower 8 bits will be the same as the
205** primary result codes above.  But the upper bits might contain
206** more specific error information.
207**
208** To extract the primary result code from an extended result code,
209** simply mask off the lower 8 bits.
210**
211**        primary = extended & 0xff;
212**
213** New result error codes may be added from time to time.  Software
214** that uses the extended result codes should plan accordingly and be
215** sure to always handle new unknown codes gracefully.
216**
217** The SQLITE_OK result code will never be extended.  It will always
218** be exactly zero.
219**
220** The extended result codes always have the primary result code
221** as a prefix.  Primary result codes only contain a single "_"
222** character.  Extended result codes contain two or more "_" characters.
223*/
224#define SQLITE_IOERR_READ          (SQLITE_IOERR | (1<<8))
225#define SQLITE_IOERR_SHORT_READ    (SQLITE_IOERR | (2<<8))
226#define SQLITE_IOERR_WRITE         (SQLITE_IOERR | (3<<8))
227#define SQLITE_IOERR_FSYNC         (SQLITE_IOERR | (4<<8))
228#define SQLITE_IOERR_DIR_FSYNC     (SQLITE_IOERR | (5<<8))
229#define SQLITE_IOERR_TRUNCATE      (SQLITE_IOERR | (6<<8))
230#define SQLITE_IOERR_FSTAT         (SQLITE_IOERR | (7<<8))
231#define SQLITE_IOERR_UNLOCK        (SQLITE_IOERR | (8<<8))
232#define SQLITE_IOERR_RDLOCK        (SQLITE_IOERR | (9<<8))
233#define SQLITE_IOERR_DELETE        (SQLITE_IOERR | (10<<8))
234
235/*
236** Enable or disable the extended result codes.
237*/
238int sqlite3_extended_result_codes(sqlite3*, int onoff);
239
240/*
241** Each entry in an SQLite table has a unique integer key.  (The key is
242** the value of the INTEGER PRIMARY KEY column if there is such a column,
243** otherwise the key is generated automatically.  The unique key is always
244** available as the ROWID, OID, or _ROWID_ column.)  The following routine
245** returns the integer key of the most recent insert in the database.
246*/
247sqlite_int64 sqlite3_last_insert_rowid(sqlite3*);
248
249/*
250** This function returns the number of database rows that were changed
251** (or inserted or deleted) by the most recent SQL statement.  Only
252** changes that are directly specified by the INSERT, UPDATE, or
253** DELETE statement are counted.  Auxiliary changes caused by
254** triggers are not counted.   Within the body of a trigger, however,
255** the sqlite3_changes() API can be called to find the number of
256** changes in the most recently completed INSERT, UPDATE, or DELETE
257** statement within the body of the trigger.
258**
259** All changes are counted, even if they were later undone by a
260** ROLLBACK or ABORT.  Except, changes associated with creating and
261** dropping tables are not counted.
262**
263** If a callback invokes sqlite3_exec() or sqlite3_step() recursively,
264** then the changes in the inner, recursive call are counted together
265** with the changes in the outer call.
266**
267** SQLite implements the command "DELETE FROM table" without a WHERE clause
268** by dropping and recreating the table.  (This is much faster than going
269** through and deleting individual elements form the table.)  Because of
270** this optimization, the change count for "DELETE FROM table" will be
271** zero regardless of the number of elements that were originally in the
272** table. To get an accurate count of the number of rows deleted, use
273** "DELETE FROM table WHERE 1" instead.
274*/
275int sqlite3_changes(sqlite3*);
276
277/*
278** This function returns the number of database rows that have been
279** modified by INSERT, UPDATE or DELETE statements since the database handle
280** was opened. This includes UPDATE, INSERT and DELETE statements executed
281** as part of trigger programs. All changes are counted as soon as the
282** statement that makes them is completed (when the statement handle is
283** passed to sqlite3_reset() or sqlite_finalise()).
284**
285** SQLite implements the command "DELETE FROM table" without a WHERE clause
286** by dropping and recreating the table.  (This is much faster than going
287** through and deleting individual elements form the table.)  Because of
288** this optimization, the change count for "DELETE FROM table" will be
289** zero regardless of the number of elements that were originally in the
290** table. To get an accurate count of the number of rows deleted, use
291** "DELETE FROM table WHERE 1" instead.
292*/
293int sqlite3_total_changes(sqlite3*);
294
295/* This function causes any pending database operation to abort and
296** return at its earliest opportunity.  This routine is typically
297** called in response to a user action such as pressing "Cancel"
298** or Ctrl-C where the user wants a long query operation to halt
299** immediately.
300**
301** It is safe to call this routine from a different thread that the
302** thread that is currently running the database operation.
303*/
304void sqlite3_interrupt(sqlite3*);
305
306
307/* These functions return true if the given input string comprises
308** one or more complete SQL statements. For the sqlite3_complete() call,
309** the parameter must be a nul-terminated UTF-8 string. For
310** sqlite3_complete16(), a nul-terminated machine byte order UTF-16 string
311** is required.
312**
313** This routine is useful for command-line input to see of the user has
314** entered a complete statement of SQL or if the current statement needs
315** to be continued on the next line.  The algorithm is simple.  If the
316** last token other than spaces and comments is a semicolon, then return
317** true.  Actually, the algorithm is a little more complicated than that
318** in order to deal with triggers, but the basic idea is the same:  the
319** statement is not complete unless it ends in a semicolon.
320*/
321int sqlite3_complete(const char *sql);
322int sqlite3_complete16(const void *sql);
323
324/*
325** This routine identifies a callback function that is invoked
326** whenever an attempt is made to open a database table that is
327** currently locked by another process or thread.  If the busy callback
328** is NULL, then sqlite3_exec() returns SQLITE_BUSY immediately if
329** it finds a locked table.  If the busy callback is not NULL, then
330** sqlite3_exec() invokes the callback with two arguments.  The
331** first argument to the handler is a copy of the void* pointer which
332** is the third argument to this routine.  The second argument to
333** the handler is the number of times that the busy handler has
334** been invoked for this locking event.  If the
335** busy callback returns 0, then sqlite3_exec() immediately returns
336** SQLITE_BUSY.  If the callback returns non-zero, then sqlite3_exec()
337** tries to open the table again and the cycle repeats.
338**
339** The presence of a busy handler does not guarantee that
340** it will be invoked when there is lock contention.
341** If SQLite determines that invoking the busy handler could result in
342** a deadlock, it will return SQLITE_BUSY instead.
343** Consider a scenario where one process is holding a read lock that
344** it is trying to promote to a reserved lock and
345** a second process is holding a reserved lock that it is trying
346** to promote to an exclusive lock.  The first process cannot proceed
347** because it is blocked by the second and the second process cannot
348** proceed because it is blocked by the first.  If both processes
349** invoke the busy handlers, neither will make any progress.  Therefore,
350** SQLite returns SQLITE_BUSY for the first process, hoping that this
351** will induce the first process to release its read lock and allow
352** the second process to proceed.
353**
354** The default busy callback is NULL.
355**
356** Sqlite is re-entrant, so the busy handler may start a new query.
357** (It is not clear why anyone would ever want to do this, but it
358** is allowed, in theory.)  But the busy handler may not close the
359** database.  Closing the database from a busy handler will delete
360** data structures out from under the executing query and will
361** probably result in a coredump.
362*/
363int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
364
365/*
366** This routine sets a busy handler that sleeps for a while when a
367** table is locked.  The handler will sleep multiple times until
368** at least "ms" milleseconds of sleeping have been done.  After
369** "ms" milleseconds of sleeping, the handler returns 0 which
370** causes sqlite3_exec() to return SQLITE_BUSY.
371**
372** Calling this routine with an argument less than or equal to zero
373** turns off all busy handlers.
374*/
375int sqlite3_busy_timeout(sqlite3*, int ms);
376
377/*
378** This next routine is really just a wrapper around sqlite3_exec().
379** Instead of invoking a user-supplied callback for each row of the
380** result, this routine remembers each row of the result in memory
381** obtained from malloc(), then returns all of the result after the
382** query has finished.
383**
384** As an example, suppose the query result where this table:
385**
386**        Name        | Age
387**        -----------------------
388**        Alice       | 43
389**        Bob         | 28
390**        Cindy       | 21
391**
392** If the 3rd argument were &azResult then after the function returns
393** azResult will contain the following data:
394**
395**        azResult[0] = "Name";
396**        azResult[1] = "Age";
397**        azResult[2] = "Alice";
398**        azResult[3] = "43";
399**        azResult[4] = "Bob";
400**        azResult[5] = "28";
401**        azResult[6] = "Cindy";
402**        azResult[7] = "21";
403**
404** Notice that there is an extra row of data containing the column
405** headers.  But the *nrow return value is still 3.  *ncolumn is
406** set to 2.  In general, the number of values inserted into azResult
407** will be ((*nrow) + 1)*(*ncolumn).
408**
409** After the calling function has finished using the result, it should
410** pass the result data pointer to sqlite3_free_table() in order to
411** release the memory that was malloc-ed.  Because of the way the
412** malloc() happens, the calling function must not try to call
413** free() directly.  Only sqlite3_free_table() is able to release
414** the memory properly and safely.
415**
416** The return value of this routine is the same as from sqlite3_exec().
417*/
418int sqlite3_get_table(
419  sqlite3*,               /* An open database */
420  const char *sql,       /* SQL to be executed */
421  char ***resultp,       /* Result written to a char *[]  that this points to */
422  int *nrow,             /* Number of result rows written here */
423  int *ncolumn,          /* Number of result columns written here */
424  char **errmsg          /* Error msg written here */
425);
426
427/*
428** Call this routine to free the memory that sqlite3_get_table() allocated.
429*/
430void sqlite3_free_table(char **result);
431
432/*
433** The following routines are variants of the "sprintf()" from the
434** standard C library.  The resulting string is written into memory
435** obtained from malloc() so that there is never a possiblity of buffer
436** overflow.  These routines also implement some additional formatting
437** options that are useful for constructing SQL statements.
438**
439** The strings returned by these routines should be freed by calling
440** sqlite3_free().
441**
442** All of the usual printf formatting options apply.  In addition, there
443** is a "%q" option.  %q works like %s in that it substitutes a null-terminated
444** string from the argument list.  But %q also doubles every '\'' character.
445** %q is designed for use inside a string literal.  By doubling each '\''
446** character it escapes that character and allows it to be inserted into
447** the string.
448**
449** For example, so some string variable contains text as follows:
450**
451**      char *zText = "It's a happy day!";
452**
453** We can use this text in an SQL statement as follows:
454**
455**      char *z = sqlite3_mprintf("INSERT INTO TABLES('%q')", zText);
456**      sqlite3_exec(db, z, callback1, 0, 0);
457**      sqlite3_free(z);
458**
459** Because the %q format string is used, the '\'' character in zText
460** is escaped and the SQL generated is as follows:
461**
462**      INSERT INTO table1 VALUES('It''s a happy day!')
463**
464** This is correct.  Had we used %s instead of %q, the generated SQL
465** would have looked like this:
466**
467**      INSERT INTO table1 VALUES('It's a happy day!');
468**
469** This second example is an SQL syntax error.  As a general rule you
470** should always use %q instead of %s when inserting text into a string
471** literal.
472*/
473char *sqlite3_mprintf(const char*,...);
474char *sqlite3_vmprintf(const char*, va_list);
475char *sqlite3_snprintf(int,char*,const char*, ...);
476
477/*
478** SQLite uses its own memory allocator.  On many installations, this
479** memory allocator is identical to the standard malloc()/realloc()/free()
480** and can be used interchangable.  On others, the implementations are
481** different.  For maximum portability, it is best not to mix calls
482** to the standard malloc/realloc/free with the sqlite versions.
483*/
484void *sqlite3_malloc(int);
485void *sqlite3_realloc(void*, int);
486void sqlite3_free(void*);
487
488#ifndef SQLITE_OMIT_AUTHORIZATION
489/*
490** This routine registers a callback with the SQLite library.  The
491** callback is invoked (at compile-time, not at run-time) for each
492** attempt to access a column of a table in the database.  The callback
493** returns SQLITE_OK if access is allowed, SQLITE_DENY if the entire
494** SQL statement should be aborted with an error and SQLITE_IGNORE
495** if the column should be treated as a NULL value.
496*/
497int sqlite3_set_authorizer(
498  sqlite3*,
499  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
500  void *pUserData
501);
502#endif
503
504/*
505** The second parameter to the access authorization function above will
506** be one of the values below.  These values signify what kind of operation
507** is to be authorized.  The 3rd and 4th parameters to the authorization
508** function will be parameters or NULL depending on which of the following
509** codes is used as the second parameter.  The 5th parameter is the name
510** of the database ("main", "temp", etc.) if applicable.  The 6th parameter
511** is the name of the inner-most trigger or view that is responsible for
512** the access attempt or NULL if this access attempt is directly from
513** input SQL code.
514**
515**                                          Arg-3           Arg-4
516*/
517#define SQLITE_COPY                  0   /* Table Name      File Name       */
518#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
519#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
520#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
521#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
522#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
523#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
524#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
525#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
526#define SQLITE_DELETE                9   /* Table Name      NULL            */
527#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
528#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
529#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
530#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
531#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
532#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
533#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
534#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
535#define SQLITE_INSERT               18   /* Table Name      NULL            */
536#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
537#define SQLITE_READ                 20   /* Table Name      Column Name     */
538#define SQLITE_SELECT               21   /* NULL            NULL            */
539#define SQLITE_TRANSACTION          22   /* NULL            NULL            */
540#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
541#define SQLITE_ATTACH               24   /* Filename        NULL            */
542#define SQLITE_DETACH               25   /* Database Name   NULL            */
543#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
544#define SQLITE_REINDEX              27   /* Index Name      NULL            */
545#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
546#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
547#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
548#define SQLITE_FUNCTION             31   /* Function Name   NULL            */
549
550/*
551** The return value of the authorization function should be one of the
552** following constants:
553*/
554/* #define SQLITE_OK  0   // Allow access (This is actually defined above) */
555#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
556#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
557
558/*
559** Register a function for tracing SQL command evaluation.  The function
560** registered by sqlite3_trace() is invoked at the first sqlite3_step()
561** for the evaluation of an SQL statement.  The function registered by
562** sqlite3_profile() runs at the end of each SQL statement and includes
563** information on how long that statement ran.
564**
565** The sqlite3_profile() API is currently considered experimental and
566** is subject to change.
567*/
568void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
569void *sqlite3_profile(sqlite3*,
570   void(*xProfile)(void*,const char*,sqlite_uint64), void*);
571
572/*
573** This routine configures a callback function - the progress callback - that
574** is invoked periodically during long running calls to sqlite3_exec(),
575** sqlite3_step() and sqlite3_get_table(). An example use for this API is to
576** keep a GUI updated during a large query.
577**
578** The progress callback is invoked once for every N virtual machine opcodes,
579** where N is the second argument to this function. The progress callback
580** itself is identified by the third argument to this function. The fourth
581** argument to this function is a void pointer passed to the progress callback
582** function each time it is invoked.
583**
584** If a call to sqlite3_exec(), sqlite3_step() or sqlite3_get_table() results
585** in less than N opcodes being executed, then the progress callback is not
586** invoked.
587**
588** To remove the progress callback altogether, pass NULL as the third
589** argument to this function.
590**
591** If the progress callback returns a result other than 0, then the current
592** query is immediately terminated and any database changes rolled back. If the
593** query was part of a larger transaction, then the transaction is not rolled
594** back and remains active. The sqlite3_exec() call returns SQLITE_ABORT.
595**
596******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
597*/
598void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
599
600/*
601** Register a callback function to be invoked whenever a new transaction
602** is committed.  The pArg argument is passed through to the callback.
603** callback.  If the callback function returns non-zero, then the commit
604** is converted into a rollback.
605**
606** If another function was previously registered, its pArg value is returned.
607** Otherwise NULL is returned.
608**
609** Registering a NULL function disables the callback.
610**
611******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
612*/
613void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
614
615/*
616** Open the sqlite database file "filename".  The "filename" is UTF-8
617** encoded for sqlite3_open() and UTF-16 encoded in the native byte order
618** for sqlite3_open16().  An sqlite3* handle is returned in *ppDb, even
619** if an error occurs. If the database is opened (or created) successfully,
620** then SQLITE_OK is returned. Otherwise an error code is returned. The
621** sqlite3_errmsg() or sqlite3_errmsg16()  routines can be used to obtain
622** an English language description of the error.
623**
624** If the database file does not exist, then a new database is created.
625** The encoding for the database is UTF-8 if sqlite3_open() is called and
626** UTF-16 if sqlite3_open16 is used.
627**
628** Whether or not an error occurs when it is opened, resources associated
629** with the sqlite3* handle should be released by passing it to
630** sqlite3_close() when it is no longer required.
631*/
632int sqlite3_open(
633  const char *filename,   /* Database filename (UTF-8) */
634  sqlite3 **ppDb          /* OUT: SQLite db handle */
635);
636int sqlite3_open16(
637  const void *filename,   /* Database filename (UTF-16) */
638  sqlite3 **ppDb          /* OUT: SQLite db handle */
639);
640
641/*
642** Return the error code for the most recent sqlite3_* API call associated
643** with sqlite3 handle 'db'. SQLITE_OK is returned if the most recent
644** API call was successful.
645**
646** Calls to many sqlite3_* functions set the error code and string returned
647** by sqlite3_errcode(), sqlite3_errmsg() and sqlite3_errmsg16()
648** (overwriting the previous values). Note that calls to sqlite3_errcode(),
649** sqlite3_errmsg() and sqlite3_errmsg16() themselves do not affect the
650** results of future invocations.
651**
652** Assuming no other intervening sqlite3_* API calls are made, the error
653** code returned by this function is associated with the same error as
654** the strings  returned by sqlite3_errmsg() and sqlite3_errmsg16().
655*/
656int sqlite3_errcode(sqlite3 *db);
657
658/*
659** Return a pointer to a UTF-8 encoded string describing in english the
660** error condition for the most recent sqlite3_* API call. The returned
661** string is always terminated by an 0x00 byte.
662**
663** The string "not an error" is returned when the most recent API call was
664** successful.
665*/
666const char *sqlite3_errmsg(sqlite3*);
667
668/*
669** Return a pointer to a UTF-16 native byte order encoded string describing
670** in english the error condition for the most recent sqlite3_* API call.
671** The returned string is always terminated by a pair of 0x00 bytes.
672**
673** The string "not an error" is returned when the most recent API call was
674** successful.
675*/
676const void *sqlite3_errmsg16(sqlite3*);
677
678/*
679** An instance of the following opaque structure is used to represent
680** a compiled SQL statment.
681*/
682typedef struct sqlite3_stmt sqlite3_stmt;
683
684/*
685** To execute an SQL query, it must first be compiled into a byte-code
686** program using one of the following routines. The only difference between
687** them is that the second argument, specifying the SQL statement to
688** compile, is assumed to be encoded in UTF-8 for the sqlite3_prepare()
689** function and UTF-16 for sqlite3_prepare16().
690**
691** The first parameter "db" is an SQLite database handle. The second
692** parameter "zSql" is the statement to be compiled, encoded as either
693** UTF-8 or UTF-16 (see above). If the next parameter, "nBytes", is less
694** than zero, then zSql is read up to the first nul terminator.  If
695** "nBytes" is not less than zero, then it is the length of the string zSql
696** in bytes (not characters).
697**
698** *pzTail is made to point to the first byte past the end of the first
699** SQL statement in zSql.  This routine only compiles the first statement
700** in zSql, so *pzTail is left pointing to what remains uncompiled.
701**
702** *ppStmt is left pointing to a compiled SQL statement that can be
703** executed using sqlite3_step().  Or if there is an error, *ppStmt may be
704** set to NULL.  If the input text contained no SQL (if the input is and
705** empty string or a comment) then *ppStmt is set to NULL.
706**
707** On success, SQLITE_OK is returned.  Otherwise an error code is returned.
708*/
709int sqlite3_prepare(
710  sqlite3 *db,            /* Database handle */
711  const char *zSql,       /* SQL statement, UTF-8 encoded */
712  int nBytes,             /* Length of zSql in bytes. */
713  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
714  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
715);
716int sqlite3_prepare16(
717  sqlite3 *db,            /* Database handle */
718  const void *zSql,       /* SQL statement, UTF-16 encoded */
719  int nBytes,             /* Length of zSql in bytes. */
720  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
721  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
722);
723
724/*
725** Newer versions of the prepare API work just like the legacy versions
726** but with one exception:  The a copy of the SQL text is saved in the
727** sqlite3_stmt structure that is returned.  If this copy exists, it
728** modifieds the behavior of sqlite3_step() slightly.  First, sqlite3_step()
729** will no longer return an SQLITE_SCHEMA error but will instead automatically
730** rerun the compiler to rebuild the prepared statement.  Secondly,
731** sqlite3_step() now turns a full result code - the result code that
732** use used to have to call sqlite3_reset() to get.
733*/
734int sqlite3_prepare_v2(
735  sqlite3 *db,            /* Database handle */
736  const char *zSql,       /* SQL statement, UTF-8 encoded */
737  int nBytes,             /* Length of zSql in bytes. */
738  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
739  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
740);
741int sqlite3_prepare16_v2(
742  sqlite3 *db,            /* Database handle */
743  const void *zSql,       /* SQL statement, UTF-16 encoded */
744  int nBytes,             /* Length of zSql in bytes. */
745  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
746  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
747);
748
749/*
750** Pointers to the following two opaque structures are used to communicate
751** with the implementations of user-defined functions.
752*/
753typedef struct sqlite3_context sqlite3_context;
754typedef struct Mem sqlite3_value;
755
756/*
757** In the SQL strings input to sqlite3_prepare() and sqlite3_prepare16(),
758** one or more literals can be replace by parameters "?" or "?NNN" or
759** ":AAA" or "@AAA" or "$VVV" where NNN is a integer, AAA is an identifer,
760** and VVV is a variable name according  to the syntax rules of the
761** TCL programming language.  The value of these parameters (also called
762** "host parameter names") can be set using the routines listed below.
763**
764** In every case, the first argument is a pointer to the sqlite3_stmt
765** structure returned from sqlite3_prepare().  The second argument is the
766** index of the host parameter name.  The first host parameter as an index
767** of 1.  For named host parameters (":AAA" or "$VVV") you can use
768** sqlite3_bind_parameter_index() to get the correct index value given
769** the parameter name.  If the same named parameter occurs more than
770** once, it is assigned the same index each time.
771**
772** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
773** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
774** text after SQLite has finished with it.  If the fifth argument is the
775** special value SQLITE_STATIC, then the library assumes that the information
776** is in static, unmanaged space and does not need to be freed.  If the
777** fifth argument has the value SQLITE_TRANSIENT, then SQLite makes its
778** own private copy of the data before the sqlite3_bind_* routine returns.
779**
780** The sqlite3_bind_* routine must be called before sqlite3_step() and after
781** an sqlite3_prepare() or sqlite3_reset().  Bindings persist across
782** multiple calls to sqlite3_reset() and sqlite3_step().  Unbound parameters
783** are interpreted as NULL.
784*/
785int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
786int sqlite3_bind_double(sqlite3_stmt*, int, double);
787int sqlite3_bind_int(sqlite3_stmt*, int, int);
788int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite_int64);
789int sqlite3_bind_null(sqlite3_stmt*, int);
790int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
791int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
792int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
793int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
794
795/*
796** Return the number of host parameters in a compiled SQL statement.  This
797** routine was added to support DBD::SQLite.
798*/
799int sqlite3_bind_parameter_count(sqlite3_stmt*);
800
801/*
802** Return the name of the i-th name parameter.  Ordinary parameters "?" are
803** nameless and a NULL is returned.  For parameters of the form :AAA or
804** $VVV the complete text of the parameter name is returned, including
805** the initial ":" or "$".  NULL is returned if the index is out of range.
806*/
807const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
808
809/*
810** Return the index of a parameter with the given name.  The name
811** must match exactly.  If no parameter with the given name is found,
812** return 0.
813*/
814int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
815
816/*
817** Set all the parameters in the compiled SQL statement to NULL.
818*/
819int sqlite3_clear_bindings(sqlite3_stmt*);
820
821/*
822** Return the number of columns in the result set returned by the compiled
823** SQL statement. This routine returns 0 if pStmt is an SQL statement
824** that does not return data (for example an UPDATE).
825*/
826int sqlite3_column_count(sqlite3_stmt *pStmt);
827
828/*
829** The first parameter is a compiled SQL statement. This function returns
830** the column heading for the Nth column of that statement, where N is the
831** second function parameter.  The string returned is UTF-8 for
832** sqlite3_column_name() and UTF-16 for sqlite3_column_name16().
833*/
834const char *sqlite3_column_name(sqlite3_stmt*,int);
835const void *sqlite3_column_name16(sqlite3_stmt*,int);
836
837/*
838** The first argument to the following calls is a compiled SQL statement.
839** These functions return information about the Nth column returned by
840** the statement, where N is the second function argument.
841**
842** If the Nth column returned by the statement is not a column value,
843** then all of the functions return NULL. Otherwise, the return the
844** name of the attached database, table and column that the expression
845** extracts a value from.
846**
847** As with all other SQLite APIs, those postfixed with "16" return UTF-16
848** encoded strings, the other functions return UTF-8. The memory containing
849** the returned strings is valid until the statement handle is finalized().
850**
851** These APIs are only available if the library was compiled with the
852** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
853*/
854const char *sqlite3_column_database_name(sqlite3_stmt*,int);
855const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
856const char *sqlite3_column_table_name(sqlite3_stmt*,int);
857const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
858const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
859const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
860
861/*
862** The first parameter is a compiled SQL statement. If this statement
863** is a SELECT statement, the Nth column of the returned result set
864** of the SELECT is a table column then the declared type of the table
865** column is returned. If the Nth column of the result set is not at table
866** column, then a NULL pointer is returned. The returned string is always
867** UTF-8 encoded. For example, in the database schema:
868**
869** CREATE TABLE t1(c1 VARIANT);
870**
871** And the following statement compiled:
872**
873** SELECT c1 + 1, c1 FROM t1;
874**
875** Then this routine would return the string "VARIANT" for the second
876** result column (i==1), and a NULL pointer for the first result column
877** (i==0).
878*/
879const char *sqlite3_column_decltype(sqlite3_stmt *, int i);
880
881/*
882** The first parameter is a compiled SQL statement. If this statement
883** is a SELECT statement, the Nth column of the returned result set
884** of the SELECT is a table column then the declared type of the table
885** column is returned. If the Nth column of the result set is not at table
886** column, then a NULL pointer is returned. The returned string is always
887** UTF-16 encoded. For example, in the database schema:
888**
889** CREATE TABLE t1(c1 INTEGER);
890**
891** And the following statement compiled:
892**
893** SELECT c1 + 1, c1 FROM t1;
894**
895** Then this routine would return the string "INTEGER" for the second
896** result column (i==1), and a NULL pointer for the first result column
897** (i==0).
898*/
899const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
900
901/*
902** After an SQL query has been compiled with a call to either
903** sqlite3_prepare() or sqlite3_prepare16(), then this function must be
904** called one or more times to execute the statement.
905**
906** The return value will be either SQLITE_BUSY, SQLITE_DONE,
907** SQLITE_ROW, SQLITE_ERROR, or SQLITE_MISUSE.
908**
909** SQLITE_BUSY means that the database engine attempted to open
910** a locked database and there is no busy callback registered.
911** Call sqlite3_step() again to retry the open.
912**
913** SQLITE_DONE means that the statement has finished executing
914** successfully.  sqlite3_step() should not be called again on this virtual
915** machine.
916**
917** If the SQL statement being executed returns any data, then
918** SQLITE_ROW is returned each time a new row of data is ready
919** for processing by the caller. The values may be accessed using
920** the sqlite3_column_*() functions described below. sqlite3_step()
921** is called again to retrieve the next row of data.
922**
923** SQLITE_ERROR means that a run-time error (such as a constraint
924** violation) has occurred.  sqlite3_step() should not be called again on
925** the VM. More information may be found by calling sqlite3_errmsg().
926**
927** SQLITE_MISUSE means that the this routine was called inappropriately.
928** Perhaps it was called on a virtual machine that had already been
929** finalized or on one that had previously returned SQLITE_ERROR or
930** SQLITE_DONE.  Or it could be the case the the same database connection
931** is being used simulataneously by two or more threads.
932*/
933int sqlite3_step(sqlite3_stmt*);
934
935/*
936** Return the number of values in the current row of the result set.
937**
938** After a call to sqlite3_step() that returns SQLITE_ROW, this routine
939** will return the same value as the sqlite3_column_count() function.
940** After sqlite3_step() has returned an SQLITE_DONE, SQLITE_BUSY or
941** error code, or before sqlite3_step() has been called on a
942** compiled SQL statement, this routine returns zero.
943*/
944int sqlite3_data_count(sqlite3_stmt *pStmt);
945
946/*
947** Values are stored in the database in one of the following fundamental
948** types.
949*/
950#define SQLITE_INTEGER  1
951#define SQLITE_FLOAT    2
952/* #define SQLITE_TEXT  3  // See below */
953#define SQLITE_BLOB     4
954#define SQLITE_NULL     5
955
956/*
957** SQLite version 2 defines SQLITE_TEXT differently.  To allow both
958** version 2 and version 3 to be included, undefine them both if a
959** conflict is seen.  Define SQLITE3_TEXT to be the version 3 value.
960*/
961#ifdef SQLITE_TEXT
962# undef SQLITE_TEXT
963#else
964# define SQLITE_TEXT     3
965#endif
966#define SQLITE3_TEXT     3
967
968/*
969** The next group of routines returns information about the information
970** in a single column of the current result row of a query.  In every
971** case the first parameter is a pointer to the SQL statement that is being
972** executed (the sqlite_stmt* that was returned from sqlite3_prepare()) and
973** the second argument is the index of the column for which information
974** should be returned.  iCol is zero-indexed.  The left-most column as an
975** index of 0.
976**
977** If the SQL statement is not currently point to a valid row, or if the
978** the colulmn index is out of range, the result is undefined.
979**
980** These routines attempt to convert the value where appropriate.  For
981** example, if the internal representation is FLOAT and a text result
982** is requested, sprintf() is used internally to do the conversion
983** automatically.  The following table details the conversions that
984** are applied:
985**
986**    Internal Type    Requested Type     Conversion
987**    -------------    --------------    --------------------------
988**       NULL             INTEGER         Result is 0
989**       NULL             FLOAT           Result is 0.0
990**       NULL             TEXT            Result is an empty string
991**       NULL             BLOB            Result is a zero-length BLOB
992**       INTEGER          FLOAT           Convert from integer to float
993**       INTEGER          TEXT            ASCII rendering of the integer
994**       INTEGER          BLOB            Same as for INTEGER->TEXT
995**       FLOAT            INTEGER         Convert from float to integer
996**       FLOAT            TEXT            ASCII rendering of the float
997**       FLOAT            BLOB            Same as FLOAT->TEXT
998**       TEXT             INTEGER         Use atoi()
999**       TEXT             FLOAT           Use atof()
1000**       TEXT             BLOB            No change
1001**       BLOB             INTEGER         Convert to TEXT then use atoi()
1002**       BLOB             FLOAT           Convert to TEXT then use atof()
1003**       BLOB             TEXT            Add a \000 terminator if needed
1004**
1005** The following access routines are provided:
1006**
1007** _type()     Return the datatype of the result.  This is one of
1008**             SQLITE_INTEGER, SQLITE_FLOAT, SQLITE_TEXT, SQLITE_BLOB,
1009**             or SQLITE_NULL.
1010** _blob()     Return the value of a BLOB.
1011** _bytes()    Return the number of bytes in a BLOB value or the number
1012**             of bytes in a TEXT value represented as UTF-8.  The \000
1013**             terminator is included in the byte count for TEXT values.
1014** _bytes16()  Return the number of bytes in a BLOB value or the number
1015**             of bytes in a TEXT value represented as UTF-16.  The \u0000
1016**             terminator is included in the byte count for TEXT values.
1017** _double()   Return a FLOAT value.
1018** _int()      Return an INTEGER value in the host computer's native
1019**             integer representation.  This might be either a 32- or 64-bit
1020**             integer depending on the host.
1021** _int64()    Return an INTEGER value as a 64-bit signed integer.
1022** _text()     Return the value as UTF-8 text.
1023** _text16()   Return the value as UTF-16 text.
1024*/
1025const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
1026int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
1027int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
1028double sqlite3_column_double(sqlite3_stmt*, int iCol);
1029int sqlite3_column_int(sqlite3_stmt*, int iCol);
1030sqlite_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
1031const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
1032const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
1033int sqlite3_column_type(sqlite3_stmt*, int iCol);
1034int sqlite3_column_numeric_type(sqlite3_stmt*, int iCol);
1035sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
1036
1037/*
1038** The sqlite3_finalize() function is called to delete a compiled
1039** SQL statement obtained by a previous call to sqlite3_prepare()
1040** or sqlite3_prepare16(). If the statement was executed successfully, or
1041** not executed at all, then SQLITE_OK is returned. If execution of the
1042** statement failed then an error code is returned.
1043**
1044** This routine can be called at any point during the execution of the
1045** virtual machine.  If the virtual machine has not completed execution
1046** when this routine is called, that is like encountering an error or
1047** an interrupt.  (See sqlite3_interrupt().)  Incomplete updates may be
1048** rolled back and transactions cancelled,  depending on the circumstances,
1049** and the result code returned will be SQLITE_ABORT.
1050*/
1051int sqlite3_finalize(sqlite3_stmt *pStmt);
1052
1053/*
1054** The sqlite3_reset() function is called to reset a compiled SQL
1055** statement obtained by a previous call to sqlite3_prepare() or
1056** sqlite3_prepare16() back to it's initial state, ready to be re-executed.
1057** Any SQL statement variables that had values bound to them using
1058** the sqlite3_bind_*() API retain their values.
1059*/
1060int sqlite3_reset(sqlite3_stmt *pStmt);
1061
1062/*
1063** The following two functions are used to add user functions or aggregates
1064** implemented in C to the SQL langauge interpreted by SQLite. The
1065** difference only between the two is that the second parameter, the
1066** name of the (scalar) function or aggregate, is encoded in UTF-8 for
1067** sqlite3_create_function() and UTF-16 for sqlite3_create_function16().
1068**
1069** The first argument is the database handle that the new function or
1070** aggregate is to be added to. If a single program uses more than one
1071** database handle internally, then user functions or aggregates must
1072** be added individually to each database handle with which they will be
1073** used.
1074**
1075** The third parameter is the number of arguments that the function or
1076** aggregate takes. If this parameter is negative, then the function or
1077** aggregate may take any number of arguments.
1078**
1079** The fourth parameter is one of SQLITE_UTF* values defined below,
1080** indicating the encoding that the function is most likely to handle
1081** values in.  This does not change the behaviour of the programming
1082** interface. However, if two versions of the same function are registered
1083** with different encoding values, SQLite invokes the version likely to
1084** minimize conversions between text encodings.
1085**
1086** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
1087** pointers to user implemented C functions that implement the user
1088** function or aggregate. A scalar function requires an implementation of
1089** the xFunc callback only, NULL pointers should be passed as the xStep
1090** and xFinal parameters. An aggregate function requires an implementation
1091** of xStep and xFinal, but NULL should be passed for xFunc. To delete an
1092** existing user function or aggregate, pass NULL for all three function
1093** callback. Specifying an inconstent set of callback values, such as an
1094** xFunc and an xFinal, or an xStep but no xFinal, SQLITE_ERROR is
1095** returned.
1096*/
1097int sqlite3_create_function(
1098  sqlite3 *,
1099  const char *zFunctionName,
1100  int nArg,
1101  int eTextRep,
1102  void*,
1103  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
1104  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1105  void (*xFinal)(sqlite3_context*)
1106);
1107int sqlite3_create_function16(
1108  sqlite3*,
1109  const void *zFunctionName,
1110  int nArg,
1111  int eTextRep,
1112  void*,
1113  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
1114  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1115  void (*xFinal)(sqlite3_context*)
1116);
1117
1118/*
1119** This function is deprecated.  Do not use it.  It continues to exist
1120** so as not to break legacy code.  But new code should avoid using it.
1121*/
1122int sqlite3_aggregate_count(sqlite3_context*);
1123
1124/*
1125** The next group of routines returns information about parameters to
1126** a user-defined function.  Function implementations use these routines
1127** to access their parameters.  These routines are the same as the
1128** sqlite3_column_* routines except that these routines take a single
1129** sqlite3_value* pointer instead of an sqlite3_stmt* and an integer
1130** column number.
1131*/
1132const void *sqlite3_value_blob(sqlite3_value*);
1133int sqlite3_value_bytes(sqlite3_value*);
1134int sqlite3_value_bytes16(sqlite3_value*);
1135double sqlite3_value_double(sqlite3_value*);
1136int sqlite3_value_int(sqlite3_value*);
1137sqlite_int64 sqlite3_value_int64(sqlite3_value*);
1138const unsigned char *sqlite3_value_text(sqlite3_value*);
1139const void *sqlite3_value_text16(sqlite3_value*);
1140const void *sqlite3_value_text16le(sqlite3_value*);
1141const void *sqlite3_value_text16be(sqlite3_value*);
1142int sqlite3_value_type(sqlite3_value*);
1143int sqlite3_value_numeric_type(sqlite3_value*);
1144
1145/*
1146** Aggregate functions use the following routine to allocate
1147** a structure for storing their state.  The first time this routine
1148** is called for a particular aggregate, a new structure of size nBytes
1149** is allocated, zeroed, and returned.  On subsequent calls (for the
1150** same aggregate instance) the same buffer is returned.  The implementation
1151** of the aggregate can use the returned buffer to accumulate data.
1152**
1153** The buffer allocated is freed automatically by SQLite.
1154*/
1155void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
1156
1157/*
1158** The pUserData parameter to the sqlite3_create_function()
1159** routine used to register user functions is available to
1160** the implementation of the function using this call.
1161*/
1162void *sqlite3_user_data(sqlite3_context*);
1163
1164/*
1165** The following two functions may be used by scalar user functions to
1166** associate meta-data with argument values. If the same value is passed to
1167** multiple invocations of the user-function during query execution, under
1168** some circumstances the associated meta-data may be preserved. This may
1169** be used, for example, to add a regular-expression matching scalar
1170** function. The compiled version of the regular expression is stored as
1171** meta-data associated with the SQL value passed as the regular expression
1172** pattern.
1173**
1174** Calling sqlite3_get_auxdata() returns a pointer to the meta data
1175** associated with the Nth argument value to the current user function
1176** call, where N is the second parameter. If no meta-data has been set for
1177** that value, then a NULL pointer is returned.
1178**
1179** The sqlite3_set_auxdata() is used to associate meta data with a user
1180** function argument. The third parameter is a pointer to the meta data
1181** to be associated with the Nth user function argument value. The fourth
1182** parameter specifies a 'delete function' that will be called on the meta
1183** data pointer to release it when it is no longer required. If the delete
1184** function pointer is NULL, it is not invoked.
1185**
1186** In practice, meta-data is preserved between function calls for
1187** expressions that are constant at compile time. This includes literal
1188** values and SQL variables.
1189*/
1190void *sqlite3_get_auxdata(sqlite3_context*, int);
1191void sqlite3_set_auxdata(sqlite3_context*, int, void*, void (*)(void*));
1192
1193
1194/*
1195** These are special value for the destructor that is passed in as the
1196** final argument to routines like sqlite3_result_blob().  If the destructor
1197** argument is SQLITE_STATIC, it means that the content pointer is constant
1198** and will never change.  It does not need to be destroyed.  The
1199** SQLITE_TRANSIENT value means that the content will likely change in
1200** the near future and that SQLite should make its own private copy of
1201** the content before returning.
1202**
1203** The typedef is necessary to work around problems in certain
1204** C++ compilers.  See ticket #2191.
1205*/
1206typedef void (*sqlite3_destructor_type)(void*);
1207#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
1208#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
1209
1210/*
1211** User-defined functions invoke the following routines in order to
1212** set their return value.
1213*/
1214void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
1215void sqlite3_result_double(sqlite3_context*, double);
1216void sqlite3_result_error(sqlite3_context*, const char*, int);
1217void sqlite3_result_error16(sqlite3_context*, const void*, int);
1218void sqlite3_result_int(sqlite3_context*, int);
1219void sqlite3_result_int64(sqlite3_context*, sqlite_int64);
1220void sqlite3_result_null(sqlite3_context*);
1221void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
1222void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
1223void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
1224void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
1225void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
1226void sqlite3_result_zeroblob(sqlite3_context*, int n);
1227void sqlite3_result_error_toobig(sqlite3_context*);
1228
1229/*
1230** These are the allowed values for the eTextRep argument to
1231** sqlite3_create_collation and sqlite3_create_function.
1232*/
1233#define SQLITE_UTF8           1
1234#define SQLITE_UTF16LE        2
1235#define SQLITE_UTF16BE        3
1236#define SQLITE_UTF16          4    /* Use native byte order */
1237#define SQLITE_ANY            5    /* sqlite3_create_function only */
1238#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
1239
1240/*
1241** These two functions are used to add new collation sequences to the
1242** sqlite3 handle specified as the first argument.
1243**
1244** The name of the new collation sequence is specified as a UTF-8 string
1245** for sqlite3_create_collation() and a UTF-16 string for
1246** sqlite3_create_collation16(). In both cases the name is passed as the
1247** second function argument.
1248**
1249** The third argument must be one of the constants SQLITE_UTF8,
1250** SQLITE_UTF16LE or SQLITE_UTF16BE, indicating that the user-supplied
1251** routine expects to be passed pointers to strings encoded using UTF-8,
1252** UTF-16 little-endian or UTF-16 big-endian respectively.
1253**
1254** A pointer to the user supplied routine must be passed as the fifth
1255** argument. If it is NULL, this is the same as deleting the collation
1256** sequence (so that SQLite cannot call it anymore). Each time the user
1257** supplied function is invoked, it is passed a copy of the void* passed as
1258** the fourth argument to sqlite3_create_collation() or
1259** sqlite3_create_collation16() as its first parameter.
1260**
1261** The remaining arguments to the user-supplied routine are two strings,
1262** each represented by a [length, data] pair and encoded in the encoding
1263** that was passed as the third argument when the collation sequence was
1264** registered. The user routine should return negative, zero or positive if
1265** the first string is less than, equal to, or greater than the second
1266** string. i.e. (STRING1 - STRING2).
1267*/
1268int sqlite3_create_collation(
1269  sqlite3*,
1270  const char *zName,
1271  int eTextRep,
1272  void*,
1273  int(*xCompare)(void*,int,const void*,int,const void*)
1274);
1275int sqlite3_create_collation16(
1276  sqlite3*,
1277  const char *zName,
1278  int eTextRep,
1279  void*,
1280  int(*xCompare)(void*,int,const void*,int,const void*)
1281);
1282
1283/*
1284****** EXPERIMENTAL - subject to change without notice **************
1285**
1286** The following experimental API is identical to the
1287** sqlite3_create_collation() function described above except that it
1288** allows a destructor callback function - xDestroy - for the new
1289** collation sequence to be specified. If this function returns
1290** successfully, the destructor function will be invoked exactly once
1291** by SQLite when one of the following occurs:
1292**
1293**   * The collation sequence is overidden by a subsequent call
1294**     to create_collation(), create_collation16() or
1295**     create_collation_v2(), or
1296**
1297**   * The database handle is closed.
1298**
1299** The argument passed to the destructor function is a copy of
1300** the void* pointer passed as the 4th argument to this function.
1301*/
1302int sqlite3_create_collation_v2(
1303  sqlite3*,
1304  const char *zName,
1305  int eTextRep,
1306  void*,
1307  int(*xCompare)(void*,int,const void*,int,const void*),
1308  void(*xDestroy)(void*)
1309);
1310
1311/*
1312** To avoid having to register all collation sequences before a database
1313** can be used, a single callback function may be registered with the
1314** database handle to be called whenever an undefined collation sequence is
1315** required.
1316**
1317** If the function is registered using the sqlite3_collation_needed() API,
1318** then it is passed the names of undefined collation sequences as strings
1319** encoded in UTF-8. If sqlite3_collation_needed16() is used, the names
1320** are passed as UTF-16 in machine native byte order. A call to either
1321** function replaces any existing callback.
1322**
1323** When the user-function is invoked, the first argument passed is a copy
1324** of the second argument to sqlite3_collation_needed() or
1325** sqlite3_collation_needed16(). The second argument is the database
1326** handle. The third argument is one of SQLITE_UTF8, SQLITE_UTF16BE or
1327** SQLITE_UTF16LE, indicating the most desirable form of the collation
1328** sequence function required. The fourth parameter is the name of the
1329** required collation sequence.
1330**
1331** The collation sequence is returned to SQLite by a collation-needed
1332** callback using the sqlite3_create_collation() or
1333** sqlite3_create_collation16() APIs, described above.
1334*/
1335int sqlite3_collation_needed(
1336  sqlite3*,
1337  void*,
1338  void(*)(void*,sqlite3*,int eTextRep,const char*)
1339);
1340int sqlite3_collation_needed16(
1341  sqlite3*,
1342  void*,
1343  void(*)(void*,sqlite3*,int eTextRep,const void*)
1344);
1345
1346/*
1347** Specify the key for an encrypted database.  This routine should be
1348** called right after sqlite3_open().
1349**
1350** The code to implement this API is not available in the public release
1351** of SQLite.
1352*/
1353int sqlite3_key(
1354  sqlite3 *db,                   /* Database to be rekeyed */
1355  const void *pKey, int nKey     /* The key */
1356);
1357
1358/*
1359** Change the key on an open database.  If the current database is not
1360** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
1361** database is decrypted.
1362**
1363** The code to implement this API is not available in the public release
1364** of SQLite.
1365*/
1366int sqlite3_rekey(
1367  sqlite3 *db,                   /* Database to be rekeyed */
1368  const void *pKey, int nKey     /* The new key */
1369);
1370
1371/*
1372** Sleep for a little while. The second parameter is the number of
1373** miliseconds to sleep for.
1374**
1375** If the operating system does not support sleep requests with
1376** milisecond time resolution, then the time will be rounded up to
1377** the nearest second. The number of miliseconds of sleep actually
1378** requested from the operating system is returned.
1379*/
1380int sqlite3_sleep(int);
1381
1382/*
1383** Return TRUE (non-zero) if the statement supplied as an argument needs
1384** to be recompiled.  A statement needs to be recompiled whenever the
1385** execution environment changes in a way that would alter the program
1386** that sqlite3_prepare() generates.  For example, if new functions or
1387** collating sequences are registered or if an authorizer function is
1388** added or changed.
1389**
1390*/
1391int sqlite3_expired(sqlite3_stmt*);
1392
1393/*
1394** Move all bindings from the first prepared statement over to the second.
1395** This routine is useful, for example, if the first prepared statement
1396** fails with an SQLITE_SCHEMA error.  The same SQL can be prepared into
1397** the second prepared statement then all of the bindings transfered over
1398** to the second statement before the first statement is finalized.
1399*/
1400int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
1401
1402/*
1403** If the following global variable is made to point to a
1404** string which is the name of a directory, then all temporary files
1405** created by SQLite will be placed in that directory.  If this variable
1406** is NULL pointer, then SQLite does a search for an appropriate temporary
1407** file directory.
1408**
1409** Once sqlite3_open() has been called, changing this variable will invalidate
1410** the current temporary database, if any.
1411*/
1412extern char *sqlite3_temp_directory;
1413
1414/*
1415** This function is called to recover from a malloc() failure that occured
1416** within the SQLite library. Normally, after a single malloc() fails the
1417** library refuses to function (all major calls return SQLITE_NOMEM).
1418** This function restores the library state so that it can be used again.
1419**
1420** All existing statements (sqlite3_stmt pointers) must be finalized or
1421** reset before this call is made. Otherwise, SQLITE_BUSY is returned.
1422** If any in-memory databases are in use, either as a main or TEMP
1423** database, SQLITE_ERROR is returned. In either of these cases, the
1424** library is not reset and remains unusable.
1425**
1426** This function is *not* threadsafe. Calling this from within a threaded
1427** application when threads other than the caller have used SQLite is
1428** dangerous and will almost certainly result in malfunctions.
1429**
1430** This functionality can be omitted from a build by defining the
1431** SQLITE_OMIT_GLOBALRECOVER at compile time.
1432*/
1433int sqlite3_global_recover(void);
1434
1435/*
1436** Test to see whether or not the database connection is in autocommit
1437** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
1438** by default.  Autocommit is disabled by a BEGIN statement and reenabled
1439** by the next COMMIT or ROLLBACK.
1440*/
1441int sqlite3_get_autocommit(sqlite3*);
1442
1443/*
1444** Return the sqlite3* database handle to which the prepared statement given
1445** in the argument belongs.  This is the same database handle that was
1446** the first argument to the sqlite3_prepare() that was used to create
1447** the statement in the first place.
1448*/
1449sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
1450
1451/*
1452** Register a callback function with the database connection identified by the
1453** first argument to be invoked whenever a row is updated, inserted or deleted.
1454** Any callback set by a previous call to this function for the same
1455** database connection is overridden.
1456**
1457** The second argument is a pointer to the function to invoke when a
1458** row is updated, inserted or deleted. The first argument to the callback is
1459** a copy of the third argument to sqlite3_update_hook. The second callback
1460** argument is one of SQLITE_INSERT, SQLITE_DELETE or SQLITE_UPDATE, depending
1461** on the operation that caused the callback to be invoked. The third and
1462** fourth arguments to the callback contain pointers to the database and
1463** table name containing the affected row. The final callback parameter is
1464** the rowid of the row. In the case of an update, this is the rowid after
1465** the update takes place.
1466**
1467** The update hook is not invoked when internal system tables are
1468** modified (i.e. sqlite_master and sqlite_sequence).
1469**
1470** If another function was previously registered, its pArg value is returned.
1471** Otherwise NULL is returned.
1472*/
1473void *sqlite3_update_hook(
1474  sqlite3*,
1475  void(*)(void *,int ,char const *,char const *,sqlite_int64),
1476  void*
1477);
1478
1479/*
1480** Register a callback to be invoked whenever a transaction is rolled
1481** back.
1482**
1483** The new callback function overrides any existing rollback-hook
1484** callback. If there was an existing callback, then it's pArg value
1485** (the third argument to sqlite3_rollback_hook() when it was registered)
1486** is returned. Otherwise, NULL is returned.
1487**
1488** For the purposes of this API, a transaction is said to have been
1489** rolled back if an explicit "ROLLBACK" statement is executed, or
1490** an error or constraint causes an implicit rollback to occur. The
1491** callback is not invoked if a transaction is automatically rolled
1492** back because the database connection is closed.
1493*/
1494void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
1495
1496/*
1497** This function is only available if the library is compiled without
1498** the SQLITE_OMIT_SHARED_CACHE macro defined. It is used to enable or
1499** disable (if the argument is true or false, respectively) the
1500** "shared pager" feature.
1501*/
1502int sqlite3_enable_shared_cache(int);
1503
1504/*
1505** Attempt to free N bytes of heap memory by deallocating non-essential
1506** memory allocations held by the database library (example: memory
1507** used to cache database pages to improve performance).
1508**
1509** This function is not a part of standard builds.  It is only created
1510** if SQLite is compiled with the SQLITE_ENABLE_MEMORY_MANAGEMENT macro.
1511*/
1512int sqlite3_release_memory(int);
1513
1514/*
1515** Place a "soft" limit on the amount of heap memory that may be allocated by
1516** SQLite within the current thread. If an internal allocation is requested
1517** that would exceed the specified limit, sqlite3_release_memory() is invoked
1518** one or more times to free up some space before the allocation is made.
1519**
1520** The limit is called "soft", because if sqlite3_release_memory() cannot free
1521** sufficient memory to prevent the limit from being exceeded, the memory is
1522** allocated anyway and the current operation proceeds.
1523**
1524** This function is only available if the library was compiled with the
1525** SQLITE_ENABLE_MEMORY_MANAGEMENT option set.
1526** memory-management has been enabled.
1527*/
1528void sqlite3_soft_heap_limit(int);
1529
1530/*
1531** This routine makes sure that all thread-local storage has been
1532** deallocated for the current thread.
1533**
1534** This routine is not technically necessary.  All thread-local storage
1535** will be automatically deallocated once memory-management and
1536** shared-cache are disabled and the soft heap limit has been set
1537** to zero.  This routine is provided as a convenience for users who
1538** want to make absolutely sure they have not forgotten something
1539** prior to killing off a thread.
1540*/
1541void sqlite3_thread_cleanup(void);
1542
1543/*
1544** Return meta information about a specific column of a specific database
1545** table accessible using the connection handle passed as the first function
1546** argument.
1547**
1548** The column is identified by the second, third and fourth parameters to
1549** this function. The second parameter is either the name of the database
1550** (i.e. "main", "temp" or an attached database) containing the specified
1551** table or NULL. If it is NULL, then all attached databases are searched
1552** for the table using the same algorithm as the database engine uses to
1553** resolve unqualified table references.
1554**
1555** The third and fourth parameters to this function are the table and column
1556** name of the desired column, respectively. Neither of these parameters
1557** may be NULL.
1558**
1559** Meta information is returned by writing to the memory locations passed as
1560** the 5th and subsequent parameters to this function. Any of these
1561** arguments may be NULL, in which case the corresponding element of meta
1562** information is ommitted.
1563**
1564** Parameter     Output Type      Description
1565** -----------------------------------
1566**
1567**   5th         const char*      Data type
1568**   6th         const char*      Name of the default collation sequence
1569**   7th         int              True if the column has a NOT NULL constraint
1570**   8th         int              True if the column is part of the PRIMARY KEY
1571**   9th         int              True if the column is AUTOINCREMENT
1572**
1573**
1574** The memory pointed to by the character pointers returned for the
1575** declaration type and collation sequence is valid only until the next
1576** call to any sqlite API function.
1577**
1578** If the specified table is actually a view, then an error is returned.
1579**
1580** If the specified column is "rowid", "oid" or "_rowid_" and an
1581** INTEGER PRIMARY KEY column has been explicitly declared, then the output
1582** parameters are set for the explicitly declared column. If there is no
1583** explicitly declared IPK column, then the output parameters are set as
1584** follows:
1585**
1586**     data type: "INTEGER"
1587**     collation sequence: "BINARY"
1588**     not null: 0
1589**     primary key: 1
1590**     auto increment: 0
1591**
1592** This function may load one or more schemas from database files. If an
1593** error occurs during this process, or if the requested table or column
1594** cannot be found, an SQLITE error code is returned and an error message
1595** left in the database handle (to be retrieved using sqlite3_errmsg()).
1596**
1597** This API is only available if the library was compiled with the
1598** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
1599*/
1600int sqlite3_table_column_metadata(
1601  sqlite3 *db,                /* Connection handle */
1602  const char *zDbName,        /* Database name or NULL */
1603  const char *zTableName,     /* Table name */
1604  const char *zColumnName,    /* Column name */
1605  char const **pzDataType,    /* OUTPUT: Declared data type */
1606  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
1607  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
1608  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
1609  int *pAutoinc               /* OUTPUT: True if colums is auto-increment */
1610);
1611
1612/*
1613****** EXPERIMENTAL - subject to change without notice **************
1614**
1615** Attempt to load an SQLite extension library contained in the file
1616** zFile.  The entry point is zProc.  zProc may be 0 in which case the
1617** name of the entry point defaults to "sqlite3_extension_init".
1618**
1619** Return SQLITE_OK on success and SQLITE_ERROR if something goes wrong.
1620**
1621** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
1622** error message text.  The calling function should free this memory
1623** by calling sqlite3_free().
1624**
1625** Extension loading must be enabled using sqlite3_enable_load_extension()
1626** prior to calling this API or an error will be returned.
1627**
1628****** EXPERIMENTAL - subject to change without notice **************
1629*/
1630int sqlite3_load_extension(
1631  sqlite3 *db,          /* Load the extension into this database connection */
1632  const char *zFile,    /* Name of the shared library containing extension */
1633  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
1634  char **pzErrMsg       /* Put error message here if not 0 */
1635);
1636
1637/*
1638** So as not to open security holes in older applications that are
1639** unprepared to deal with extension load, and as a means of disabling
1640** extension loading while executing user-entered SQL, the following
1641** API is provided to turn the extension loading mechanism on and
1642** off.  It is off by default.  See ticket #1863.
1643**
1644** Call this routine with onoff==1 to turn extension loading on
1645** and call it with onoff==0 to turn it back off again.
1646*/
1647int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
1648
1649/*
1650****** EXPERIMENTAL - subject to change without notice **************
1651**
1652** Register an extension entry point that is automatically invoked
1653** whenever a new database connection is opened.
1654**
1655** This API can be invoked at program startup in order to register
1656** one or more statically linked extensions that will be available
1657** to all new database connections.
1658**
1659** Duplicate extensions are detected so calling this routine multiple
1660** times with the same extension is harmless.
1661**
1662** This routine stores a pointer to the extension in an array
1663** that is obtained from malloc().  If you run a memory leak
1664** checker on your program and it reports a leak because of this
1665** array, then invoke sqlite3_automatic_extension_reset() prior
1666** to shutdown to free the memory.
1667**
1668** Automatic extensions apply across all threads.
1669*/
1670int sqlite3_auto_extension(void *xEntryPoint);
1671
1672
1673/*
1674****** EXPERIMENTAL - subject to change without notice **************
1675**
1676** Disable all previously registered automatic extensions.  This
1677** routine undoes the effect of all prior sqlite3_automatic_extension()
1678** calls.
1679**
1680** This call disabled automatic extensions in all threads.
1681*/
1682void sqlite3_reset_auto_extension(void);
1683
1684
1685/*
1686****** EXPERIMENTAL - subject to change without notice **************
1687**
1688** The interface to the virtual-table mechanism is currently considered
1689** to be experimental.  The interface might change in incompatible ways.
1690** If this is a problem for you, do not use the interface at this time.
1691**
1692** When the virtual-table mechanism stablizes, we will declare the
1693** interface fixed, support it indefinitely, and remove this comment.
1694*/
1695
1696/*
1697** Structures used by the virtual table interface
1698*/
1699typedef struct sqlite3_vtab sqlite3_vtab;
1700typedef struct sqlite3_index_info sqlite3_index_info;
1701typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
1702typedef struct sqlite3_module sqlite3_module;
1703
1704/*
1705** A module is a class of virtual tables.  Each module is defined
1706** by an instance of the following structure.  This structure consists
1707** mostly of methods for the module.
1708*/
1709struct sqlite3_module {
1710  int iVersion;
1711  int (*xCreate)(sqlite3*, void *pAux,
1712               int argc, const char *const*argv,
1713               sqlite3_vtab **ppVTab, char**);
1714  int (*xConnect)(sqlite3*, void *pAux,
1715               int argc, const char *const*argv,
1716               sqlite3_vtab **ppVTab, char**);
1717  int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
1718  int (*xDisconnect)(sqlite3_vtab *pVTab);
1719  int (*xDestroy)(sqlite3_vtab *pVTab);
1720  int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
1721  int (*xClose)(sqlite3_vtab_cursor*);
1722  int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
1723                int argc, sqlite3_value **argv);
1724  int (*xNext)(sqlite3_vtab_cursor*);
1725  int (*xEof)(sqlite3_vtab_cursor*);
1726  int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
1727  int (*xRowid)(sqlite3_vtab_cursor*, sqlite_int64 *pRowid);
1728  int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite_int64 *);
1729  int (*xBegin)(sqlite3_vtab *pVTab);
1730  int (*xSync)(sqlite3_vtab *pVTab);
1731  int (*xCommit)(sqlite3_vtab *pVTab);
1732  int (*xRollback)(sqlite3_vtab *pVTab);
1733  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
1734                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
1735                       void **ppArg);
1736};
1737
1738/*
1739** The sqlite3_index_info structure and its substructures is used to
1740** pass information into and receive the reply from the xBestIndex
1741** method of an sqlite3_module.  The fields under **Inputs** are the
1742** inputs to xBestIndex and are read-only.  xBestIndex inserts its
1743** results into the **Outputs** fields.
1744**
1745** The aConstraint[] array records WHERE clause constraints of the
1746** form:
1747**
1748**         column OP expr
1749**
1750** Where OP is =, <, <=, >, or >=.  The particular operator is stored
1751** in aConstraint[].op.  The index of the column is stored in
1752** aConstraint[].iColumn.  aConstraint[].usable is TRUE if the
1753** expr on the right-hand side can be evaluated (and thus the constraint
1754** is usable) and false if it cannot.
1755**
1756** The optimizer automatically inverts terms of the form "expr OP column"
1757** and makes other simplificatinos to the WHERE clause in an attempt to
1758** get as many WHERE clause terms into the form shown above as possible.
1759** The aConstraint[] array only reports WHERE clause terms in the correct
1760** form that refer to the particular virtual table being queried.
1761**
1762** Information about the ORDER BY clause is stored in aOrderBy[].
1763** Each term of aOrderBy records a column of the ORDER BY clause.
1764**
1765** The xBestIndex method must fill aConstraintUsage[] with information
1766** about what parameters to pass to xFilter.  If argvIndex>0 then
1767** the right-hand side of the corresponding aConstraint[] is evaluated
1768** and becomes the argvIndex-th entry in argv.  If aConstraintUsage[].omit
1769** is true, then the constraint is assumed to be fully handled by the
1770** virtual table and is not checked again by SQLite.
1771**
1772** The idxNum and idxPtr values are recorded and passed into xFilter.
1773** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true.
1774**
1775** The orderByConsumed means that output from xFilter will occur in
1776** the correct order to satisfy the ORDER BY clause so that no separate
1777** sorting step is required.
1778**
1779** The estimatedCost value is an estimate of the cost of doing the
1780** particular lookup.  A full scan of a table with N entries should have
1781** a cost of N.  A binary search of a table of N entries should have a
1782** cost of approximately log(N).
1783*/
1784struct sqlite3_index_info {
1785  /* Inputs */
1786  const int nConstraint;     /* Number of entries in aConstraint */
1787  const struct sqlite3_index_constraint {
1788     int iColumn;              /* Column on left-hand side of constraint */
1789     unsigned char op;         /* Constraint operator */
1790     unsigned char usable;     /* True if this constraint is usable */
1791     int iTermOffset;          /* Used internally - xBestIndex should ignore */
1792  } *const aConstraint;      /* Table of WHERE clause constraints */
1793  const int nOrderBy;        /* Number of terms in the ORDER BY clause */
1794  const struct sqlite3_index_orderby {
1795     int iColumn;              /* Column number */
1796     unsigned char desc;       /* True for DESC.  False for ASC. */
1797  } *const aOrderBy;         /* The ORDER BY clause */
1798
1799  /* Outputs */
1800  struct sqlite3_index_constraint_usage {
1801    int argvIndex;           /* if >0, constraint is part of argv to xFilter */
1802    unsigned char omit;      /* Do not code a test for this constraint */
1803  } *const aConstraintUsage;
1804  int idxNum;                /* Number used to identify the index */
1805  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
1806  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
1807  int orderByConsumed;       /* True if output is already ordered */
1808  double estimatedCost;      /* Estimated cost of using this index */
1809};
1810#define SQLITE_INDEX_CONSTRAINT_EQ    2
1811#define SQLITE_INDEX_CONSTRAINT_GT    4
1812#define SQLITE_INDEX_CONSTRAINT_LE    8
1813#define SQLITE_INDEX_CONSTRAINT_LT    16
1814#define SQLITE_INDEX_CONSTRAINT_GE    32
1815#define SQLITE_INDEX_CONSTRAINT_MATCH 64
1816
1817/*
1818** This routine is used to register a new module name with an SQLite
1819** connection.  Module names must be registered before creating new
1820** virtual tables on the module, or before using preexisting virtual
1821** tables of the module.
1822*/
1823int sqlite3_create_module(
1824  sqlite3 *db,               /* SQLite connection to register module with */
1825  const char *zName,         /* Name of the module */
1826  const sqlite3_module *,    /* Methods for the module */
1827  void *                     /* Client data for xCreate/xConnect */
1828);
1829
1830/*
1831** Every module implementation uses a subclass of the following structure
1832** to describe a particular instance of the module.  Each subclass will
1833** be taylored to the specific needs of the module implementation.   The
1834** purpose of this superclass is to define certain fields that are common
1835** to all module implementations.
1836**
1837** Virtual tables methods can set an error message by assigning a
1838** string obtained from sqlite3_mprintf() to zErrMsg.  The method should
1839** take care that any prior string is freed by a call to sqlite3_free()
1840** prior to assigning a new string to zErrMsg.  After the error message
1841** is delivered up to the client application, the string will be automatically
1842** freed by sqlite3_free() and the zErrMsg field will be zeroed.  Note
1843** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field
1844** since virtual tables are commonly implemented in loadable extensions which
1845** do not have access to sqlite3MPrintf() or sqlite3Free().
1846*/
1847struct sqlite3_vtab {
1848  const sqlite3_module *pModule;  /* The module for this virtual table */
1849  int nRef;                       /* Used internally */
1850  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
1851  /* Virtual table implementations will typically add additional fields */
1852};
1853
1854/* Every module implementation uses a subclass of the following structure
1855** to describe cursors that point into the virtual table and are used
1856** to loop through the virtual table.  Cursors are created using the
1857** xOpen method of the module.  Each module implementation will define
1858** the content of a cursor structure to suit its own needs.
1859**
1860** This superclass exists in order to define fields of the cursor that
1861** are common to all implementations.
1862*/
1863struct sqlite3_vtab_cursor {
1864  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
1865  /* Virtual table implementations will typically add additional fields */
1866};
1867
1868/*
1869** The xCreate and xConnect methods of a module use the following API
1870** to declare the format (the names and datatypes of the columns) of
1871** the virtual tables they implement.
1872*/
1873int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);
1874
1875/*
1876** Virtual tables can provide alternative implementations of functions
1877** using the xFindFunction method.  But global versions of those functions
1878** must exist in order to be overloaded.
1879**
1880** This API makes sure a global version of a function with a particular
1881** name and number of parameters exists.  If no such function exists
1882** before this API is called, a new function is created.  The implementation
1883** of the new function always causes an exception to be thrown.  So
1884** the new function is not good for anything by itself.  Its only
1885** purpose is to be a place-holder function that can be overloaded
1886** by virtual tables.
1887**
1888** This API should be considered part of the virtual table interface,
1889** which is experimental and subject to change.
1890*/
1891int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
1892
1893/*
1894** The interface to the virtual-table mechanism defined above (back up
1895** to a comment remarkably similar to this one) is currently considered
1896** to be experimental.  The interface might change in incompatible ways.
1897** If this is a problem for you, do not use the interface at this time.
1898**
1899** When the virtual-table mechanism stablizes, we will declare the
1900** interface fixed, support it indefinitely, and remove this comment.
1901**
1902****** EXPERIMENTAL - subject to change without notice **************
1903*/
1904
1905/*
1906** An instance of the following opaque structure is used to
1907** represent an open blob handle.
1908*/
1909typedef struct sqlite3_blob sqlite3_blob;
1910
1911/*
1912** Open a handle to the blob located in row iRow,, column zColumn,
1913** table zTable in database zDb. i.e. the same blob that would
1914** be selected by:
1915**
1916**     "SELECT zColumn FROM zDb.zTable WHERE rowid = iRow;
1917**
1918** If the flags parameter is non-zero, the blob is opened for
1919** read and write access. If it is zero, the blob is opened for read
1920** access.
1921**
1922** On success, SQLITE_OK is returned and the new blob-handle is
1923** written to *ppBlob. Otherwise an error code is returned and
1924** any value written to *ppBlob should not be used by the caller.
1925** This function sets the database-handle error code and message
1926** accessible via sqlite3_errcode() and sqlite3_errmsg().
1927*/
1928int sqlite3_blob_open(
1929  sqlite3*,
1930  const char *zDb,
1931  const char *zTable,
1932  const char *zColumn,
1933  sqlite_int64 iRow,
1934  int flags,
1935  sqlite3_blob **ppBlob
1936);
1937
1938/*
1939** Close an open blob handle.
1940*/
1941int sqlite3_blob_close(sqlite3_blob *);
1942
1943/*
1944** Return the size in bytes of the blob accessible via the open
1945** blob-handle passed as an argument.
1946*/
1947int sqlite3_blob_bytes(sqlite3_blob *);
1948
1949/*
1950** This function is used to read data from an open blob-handle into
1951** a caller supplied buffer. n bytes of data are copied into buffer
1952** z from the open blob, starting at offset iOffset.
1953**
1954** On success, SQLITE_OK is returned. Otherwise, an SQLite error
1955** code.
1956*/
1957int sqlite3_blob_read(sqlite3_blob *, void *z, int n, int iOffset);
1958
1959/*
1960** This function is used to write data from an open blob-handle into
1961** a user supplied buffer. n bytes of data are copied from the buffer
1962** pointed to by z into the open blob, starting at offset iOffset.
1963**
1964** If the blob-handle passed as the first argument was not opened for
1965** writing (the flags parameter to sqlite3_blob_open was zero), this
1966** function returns SQLITE_READONLY.
1967**
1968** This function may only modify the contents of the blob, it is
1969** not possible to increase the size of a blob using this API. If
1970** offset iOffset is less than n bytes from the end of the blob,
1971** SQLITE_ERROR is returned and no data is written.
1972**
1973** On success, SQLITE_OK is returned. Otherwise, an SQLite error
1974** code. If an error occurs, this function sets the
1975*/
1976int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
1977
1978/*
1979** Undo the hack that converts floating point types to integer for
1980** builds on processors without floating point support.
1981*/
1982#ifdef SQLITE_OMIT_FLOATING_POINT
1983# undef double
1984#endif
1985
1986#ifdef __cplusplus
1987}  /* End of the 'extern "C"' block */
1988#endif
1989#endif
1990