xref: /sqlite-3.40.0/src/sqlite.h.in (revision 5665b3ea)
1/*
2** 2001 September 15
3**
4** The author disclaims copyright to this source code.  In place of
5** a legal notice, here is a blessing:
6**
7**    May you do good and not evil.
8**    May you find forgiveness for yourself and forgive others.
9**    May you share freely, never taking more than you give.
10**
11*************************************************************************
12** This header file defines the interface that the SQLite library
13** presents to client programs.  If a C-function, structure, datatype,
14** or constant definition does not appear in this file, then it is
15** not a published API of SQLite, is subject to change without
16** notice, and should not be referenced by programs that use SQLite.
17**
18** Some of the definitions that are in this file are marked as
19** "experimental".  Experimental interfaces are normally new
20** features recently added to SQLite.  We do not anticipate changes
21** to experimental interfaces but reserve to make minor changes if
22** experience from use "in the wild" suggest such changes are prudent.
23**
24** The official C-language API documentation for SQLite is derived
25** from comments in this file.  This file is the authoritative source
26** on how SQLite interfaces are suppose to operate.
27**
28** The name of this file under configuration management is "sqlite.h.in".
29** The makefile makes some minor changes to this file (such as inserting
30** the version number) and changes its name to "sqlite3.h" as
31** part of the build process.
32**
33** @(#) $Id: sqlite.h.in,v 1.215 2007/06/22 15:21:16 danielk1977 Exp $
34*/
35#ifndef _SQLITE3_H_
36#define _SQLITE3_H_
37#include <stdarg.h>     /* Needed for the definition of va_list */
38
39/*
40** Make sure we can call this stuff from C++.
41*/
42#ifdef __cplusplus
43extern "C" {
44#endif
45
46/*
47** Make sure these symbols where not defined by some previous header
48** file.
49*/
50#ifdef SQLITE_VERSION
51# undef SQLITE_VERSION
52#endif
53#ifdef SQLITE_VERSION_NUMBER
54# undef SQLITE_VERSION_NUMBER
55#endif
56
57/*
58** CAPI3REF: Compile-Time Library Version Numbers
59**
60** The version of the SQLite library is contained in the sqlite3.h
61** header file in a #define named SQLITE_VERSION.  The SQLITE_VERSION
62** macro resolves to a string constant.
63**
64** The format of the version string is "X.Y.Z", where
65** X is the major version number, Y is the minor version number and Z
66** is the release number.  The X.Y.Z might be followed by "alpha" or "beta".
67** For example "3.1.1beta".
68**
69** The X value is always 3 in SQLite.  The X value only changes when
70** backwards compatibility is broken and we intend to never break
71** backwards compatibility.  The Y value only changes when
72** there are major feature enhancements that are forwards compatible
73** but not backwards compatible.  The Z value is incremented with
74** each release but resets back to 0 when Y is incremented.
75**
76** The SQLITE_VERSION_NUMBER is an integer with the value
77** (X*1000000 + Y*1000 + Z). For example, for version "3.1.1beta",
78** SQLITE_VERSION_NUMBER is set to 3001001. To detect if they are using
79** version 3.1.1 or greater at compile time, programs may use the test
80** (SQLITE_VERSION_NUMBER>=3001001).
81**
82** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()].
83*/
84#define SQLITE_VERSION         "--VERS--"
85#define SQLITE_VERSION_NUMBER --VERSION-NUMBER--
86
87/*
88** CAPI3REF: Run-Time Library Version Numbers
89**
90** These routines return values equivalent to the header constants
91** [SQLITE_VERSION] and [SQLITE_VERSION_NUMBER].  The values returned
92** by this routines should only be different from the header values
93** if you compile your program using an sqlite3.h header from a
94** different version of SQLite that the version of the library you
95** link against.
96**
97** The sqlite3_version[] string constant contains the text of the
98** [SQLITE_VERSION] string.  The sqlite3_libversion() function returns
99** a poiner to the sqlite3_version[] string constant.  The function
100** is provided for DLL users who can only access functions and not
101** constants within the DLL.
102*/
103extern const char sqlite3_version[];
104const char *sqlite3_libversion(void);
105int sqlite3_libversion_number(void);
106
107/*
108** CAPI3REF: Database Connection Handle
109**
110** Each open SQLite database is represented by pointer to an instance of the
111** opaque structure named "sqlite3".  It is useful to think of an sqlite3
112** pointer as an object.  The [sqlite3_open] interface is its constructor
113** and [sqlite3_close] is its destructor.  There are many other interfaces
114** (such as [sqlite3_prepare_v2], [sqlite3_create_function], and
115** [sqlite3_busy_timeout] to name but three) that are methods on this
116** object.
117*/
118typedef struct sqlite3 sqlite3;
119
120
121/*
122** CAPI3REF: 64-Bit Integer Types
123**
124** Some compilers do not support the "long long" datatype.  So we have
125** to do compiler-specific typedefs for 64-bit signed and unsigned integers.
126**
127** Many SQLite interface functions require a 64-bit integer arguments.
128** Those interfaces are declared using this typedef.
129*/
130#ifdef SQLITE_INT64_TYPE
131  typedef SQLITE_INT64_TYPE sqlite_int64;
132  typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
133#elif defined(_MSC_VER) || defined(__BORLANDC__)
134  typedef __int64 sqlite_int64;
135  typedef unsigned __int64 sqlite_uint64;
136#else
137  typedef long long int sqlite_int64;
138  typedef unsigned long long int sqlite_uint64;
139#endif
140
141/*
142** If compiling for a processor that lacks floating point support,
143** substitute integer for floating-point
144*/
145#ifdef SQLITE_OMIT_FLOATING_POINT
146# define double sqlite_int64
147#endif
148
149/*
150** CAPI3REF: Closing A Database Connection
151**
152** Call this function with a pointer to a structure that was previously
153** returned from [sqlite3_open()] and the corresponding database will by
154** closed.
155**
156** All SQL statements prepared using [sqlite3_prepare_v2()] or
157** [sqlite3_prepare16_v2()] must be destroyed using [sqlite3_finalize()]
158** before this routine is called. Otherwise, SQLITE_BUSY is returned and the
159** database connection remains open.
160*/
161int sqlite3_close(sqlite3 *);
162
163/*
164** The type for a callback function.
165** This is legacy and deprecated.  It is included for historical
166** compatibility and is not documented.
167*/
168typedef int (*sqlite3_callback)(void*,int,char**, char**);
169
170/*
171** CAPI3REF: One-Step Query Execution Interface
172**
173** This interface is used to do a one-time evaluatation of zero
174** or more SQL statements.  UTF-8 text of the SQL statements to
175** be evaluted is passed in as the second parameter.  The statements
176** are prepared one by one using [sqlite3_prepare()], evaluated
177** using [sqlite3_step()], then destroyed using [sqlite3_finalize()].
178**
179** If one or more of the SQL statements are queries, then
180** the callback function specified by the 3rd parameter is
181** invoked once for each row of the query result.  This callback
182** should normally return 0.  If the callback returns a non-zero
183** value then the query is aborted, all subsequent SQL statements
184** are skipped and the sqlite3_exec() function returns the SQLITE_ABORT.
185**
186** The 4th parameter to this interface is an arbitrary pointer that is
187** passed through to the callback function as its first parameter.
188**
189** The 2nd parameter to the callback function is the number of
190** columns in the query result.  The 3rd parameter to the callback
191** is an array of strings holding the values for each column
192** as extracted using [sqlite3_column_text()].
193** The 4th parameter to the callback is an array of strings
194** obtained using [sqlite3_column_name()] and holding
195** the names of each column.
196**
197** The callback function may be NULL, even for queries.  A NULL
198** callback is not an error.  It just means that no callback
199** will be invoked.
200**
201** If an error occurs while parsing or evaluating the SQL (but
202** not while executing the callback) then an appropriate error
203** message is written into memory obtained from [sqlite3_malloc()] and
204** *errmsg is made to point to that message.  The calling function
205** is responsible for freeing the memory that holds the error
206** message.   Use [sqlite3_free()] for this.  If errmsg==NULL,
207** then no error message is ever written.
208**
209** The return value is is SQLITE_OK if there are no errors and
210** some other [SQLITE_OK | return code] if there is an error.
211** The particular return value depends on the type of error.
212**
213*/
214int sqlite3_exec(
215  sqlite3*,                                  /* An open database */
216  const char *sql,                           /* SQL to be evaluted */
217  int (*callback)(void*,int,char**,char**),  /* Callback function */
218  void *,                                    /* 1st argument to callback */
219  char **errmsg                              /* Error msg written here */
220);
221
222/*
223** CAPI3REF: Result Codes
224** KEYWORDS: SQLITE_OK
225**
226** Many SQLite functions return an integer result code from the set shown
227** above in order to indicates success or failure.
228**
229** The result codes above are the only ones returned by SQLite in its
230** default configuration.  However, the [sqlite3_extended_result_codes()]
231** API can be used to set a database connectoin to return more detailed
232** result codes.
233**
234** See also: [SQLITE_IOERR_READ | extended result codes]
235**
236*/
237#define SQLITE_OK           0   /* Successful result */
238/* beginning-of-error-codes */
239#define SQLITE_ERROR        1   /* SQL error or missing database */
240#define SQLITE_INTERNAL     2   /* NOT USED. Internal logic error in SQLite */
241#define SQLITE_PERM         3   /* Access permission denied */
242#define SQLITE_ABORT        4   /* Callback routine requested an abort */
243#define SQLITE_BUSY         5   /* The database file is locked */
244#define SQLITE_LOCKED       6   /* A table in the database is locked */
245#define SQLITE_NOMEM        7   /* A malloc() failed */
246#define SQLITE_READONLY     8   /* Attempt to write a readonly database */
247#define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
248#define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
249#define SQLITE_CORRUPT     11   /* The database disk image is malformed */
250#define SQLITE_NOTFOUND    12   /* NOT USED. Table or record not found */
251#define SQLITE_FULL        13   /* Insertion failed because database is full */
252#define SQLITE_CANTOPEN    14   /* Unable to open the database file */
253#define SQLITE_PROTOCOL    15   /* NOT USED. Database lock protocol error */
254#define SQLITE_EMPTY       16   /* Database is empty */
255#define SQLITE_SCHEMA      17   /* The database schema changed */
256#define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
257#define SQLITE_CONSTRAINT  19   /* Abort due to contraint violation */
258#define SQLITE_MISMATCH    20   /* Data type mismatch */
259#define SQLITE_MISUSE      21   /* Library used incorrectly */
260#define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
261#define SQLITE_AUTH        23   /* Authorization denied */
262#define SQLITE_FORMAT      24   /* Auxiliary database format error */
263#define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
264#define SQLITE_NOTADB      26   /* File opened that is not a database file */
265#define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
266#define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
267/* end-of-error-codes */
268
269/*
270** CAPI3REF: Extended Result Codes
271**
272** In its default configuration, SQLite API routines return one of 26 integer
273** result codes described at result-codes.  However, experience has shown that
274** many of these result codes are too course-grained.  They do not provide as
275** much information about problems as users might like.  In an effort to
276** address this, newer versions of SQLite (version 3.3.8 and later) include
277** support for additional result codes that provide more detailed information
278** about errors.  The extended result codes are enabled (or disabled) for
279** each database
280** connection using the [sqlite3_extended_result_codes()] API.
281**
282** Some of the available extended result codes are listed above.
283** We expect the number of extended result codes will be expand
284** over time.  Software that uses extended result codes should expect
285** to see new result codes in future releases of SQLite.
286**
287** The symbolic name for an extended result code always contains a related
288** primary result code as a prefix.  Primary result codes contain a single
289** "_" character.  Extended result codes contain two or more "_" characters.
290** The numeric value of an extended result code can be converted to its
291** corresponding primary result code by masking off the lower 8 bytes.
292**
293** The SQLITE_OK result code will never be extended.  It will always
294** be exactly zero.
295*/
296#define SQLITE_IOERR_READ          (SQLITE_IOERR | (1<<8))
297#define SQLITE_IOERR_SHORT_READ    (SQLITE_IOERR | (2<<8))
298#define SQLITE_IOERR_WRITE         (SQLITE_IOERR | (3<<8))
299#define SQLITE_IOERR_FSYNC         (SQLITE_IOERR | (4<<8))
300#define SQLITE_IOERR_DIR_FSYNC     (SQLITE_IOERR | (5<<8))
301#define SQLITE_IOERR_TRUNCATE      (SQLITE_IOERR | (6<<8))
302#define SQLITE_IOERR_FSTAT         (SQLITE_IOERR | (7<<8))
303#define SQLITE_IOERR_UNLOCK        (SQLITE_IOERR | (8<<8))
304#define SQLITE_IOERR_RDLOCK        (SQLITE_IOERR | (9<<8))
305#define SQLITE_IOERR_DELETE        (SQLITE_IOERR | (10<<8))
306#define SQLITE_IOERR_BLOCKED       (SQLITE_IOERR | (11<<8))
307
308/*
309** CAPI3REF: Enable Or Disable Extended Result Codes
310**
311** This routine enables or disables the
312** [SQLITE_IOERR_READ | extended result codes] feature.
313** By default, SQLite API routines return one of only 26 integer
314** [SQLITE_OK | result codes].  When extended result codes
315** are enabled by this routine, the repetoire of result codes can be
316** much larger and can (hopefully) provide more detailed information
317** about the cause of an error.
318**
319** The second argument is a boolean value that turns extended result
320** codes on and off.  Extended result codes are off by default for
321** backwards compatibility with older versions of SQLite.
322*/
323int sqlite3_extended_result_codes(sqlite3*, int onoff);
324
325/*
326** CAPI3REF: Last Insert Rowid
327**
328** Each entry in an SQLite table has a unique 64-bit signed integer key
329** called the "rowid". The rowid is always available as an undeclared
330** column named ROWID, OID, or _ROWID_.  If the table has a column of
331** type INTEGER PRIMARY KEY then that column is another an alias for the
332** rowid.
333**
334** This routine returns the rowid of the most recent INSERT into
335** the database from the database connection given in the first
336** argument.  If no inserts have ever occurred on this database
337** connection, zero is returned.
338**
339** If an INSERT occurs within a trigger, then the rowid of the
340** inserted row is returned by this routine as long as the trigger
341** is running.  But once the trigger terminates, the value returned
342** by this routine reverts to the last value inserted before the
343** trigger fired.
344*/
345sqlite_int64 sqlite3_last_insert_rowid(sqlite3*);
346
347/*
348** CAPI3REF: Count The Number Of Rows Modified
349**
350** This function returns the number of database rows that were changed
351** (or inserted or deleted) by the most recent SQL statement.  Only
352** changes that are directly specified by the INSERT, UPDATE, or
353** DELETE statement are counted.  Auxiliary changes caused by
354** triggers are not counted.  Use the [sqlite3_total_changes()] function
355** to find the total number of changes including changes caused by triggers.
356**
357** Within the body of a trigger, the sqlite3_changes() interface can be
358** called to find the number of
359** changes in the most recently completed INSERT, UPDATE, or DELETE
360** statement within the body of the trigger.
361**
362** All changes are counted, even if they were later undone by a
363** ROLLBACK or ABORT.  Except, changes associated with creating and
364** dropping tables are not counted.
365**
366** If a callback invokes [sqlite3_exec()] or [sqlite3_step()] recursively,
367** then the changes in the inner, recursive call are counted together
368** with the changes in the outer call.
369**
370** SQLite implements the command "DELETE FROM table" without a WHERE clause
371** by dropping and recreating the table.  (This is much faster than going
372** through and deleting individual elements form the table.)  Because of
373** this optimization, the change count for "DELETE FROM table" will be
374** zero regardless of the number of elements that were originally in the
375** table. To get an accurate count of the number of rows deleted, use
376** "DELETE FROM table WHERE 1" instead.
377*/
378int sqlite3_changes(sqlite3*);
379
380/*
381** CAPI3REF: Total Number Of Rows Modified
382***
383** This function returns the number of database rows that have been
384** modified by INSERT, UPDATE or DELETE statements since the database handle
385** was opened. This includes UPDATE, INSERT and DELETE statements executed
386** as part of trigger programs. All changes are counted as soon as the
387** statement that makes them is completed (when the statement handle is
388** passed to [sqlite3_reset()] or [sqlite_finalise()]).
389**
390** See also the [sqlite3_change()] interface.
391**
392** SQLite implements the command "DELETE FROM table" without a WHERE clause
393** by dropping and recreating the table.  (This is much faster than going
394** through and deleting individual elements form the table.)  Because of
395** this optimization, the change count for "DELETE FROM table" will be
396** zero regardless of the number of elements that were originally in the
397** table. To get an accurate count of the number of rows deleted, use
398** "DELETE FROM table WHERE 1" instead.
399*/
400int sqlite3_total_changes(sqlite3*);
401
402/*
403** CAPI3REF: Interrupt A Long-Running Query
404**
405** This function causes any pending database operation to abort and
406** return at its earliest opportunity.  This routine is typically
407** called in response to a user action such as pressing "Cancel"
408** or Ctrl-C where the user wants a long query operation to halt
409** immediately.
410**
411** It is safe to call this routine from a thread different from the
412** thread that is currently running the database operation.
413**
414** The SQL operation that is interrupted will return [SQLITE_INTERRUPT].
415** If an interrupted operation was an update that is inside an
416** explicit transaction, then the entire transaction will be rolled
417** back automatically.
418*/
419void sqlite3_interrupt(sqlite3*);
420
421/*
422** CAPI3REF: Determine If An SQL Statement Is Complete
423**
424** These functions return true if the given input string comprises
425** one or more complete SQL statements. For the sqlite3_complete() call,
426** the parameter must be a nul-terminated UTF-8 string. For
427** sqlite3_complete16(), a nul-terminated machine byte order UTF-16 string
428** is required.
429**
430** These routines are useful for command-line input to determine if the
431** currently entered text forms one or more complete SQL statements or
432** if additional input is needed before sending the statements into
433** SQLite for parsing. The algorithm is simple.  If the
434** last token other than spaces and comments is a semicolon, then return
435** true.  Actually, the algorithm is a little more complicated than that
436** in order to deal with triggers, but the basic idea is the same:  the
437** statement is not complete unless it ends in a semicolon.
438*/
439int sqlite3_complete(const char *sql);
440int sqlite3_complete16(const void *sql);
441
442/*
443** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
444**
445** This routine identifies a callback function that might be invoked
446** whenever an attempt is made to open a database table
447** that another thread or process has locked.
448** If the busy callback is NULL, then [SQLITE_BUSY]
449** (or sometimes [SQLITE_IOERR_BLOCKED])
450** is returned immediately upon encountering the lock.
451** If the busy callback is not NULL, then the
452** callback will be invoked with two arguments.  The
453** first argument to the handler is a copy of the void* pointer which
454** is the third argument to this routine.  The second argument to
455** the handler is the number of times that the busy handler has
456** been invoked for this locking event. If the
457** busy callback returns 0, then no additional attempts are made to
458** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
459** If the callback returns non-zero, then another attempt is made to open the
460** database for reading and the cycle repeats.
461**
462** The presence of a busy handler does not guarantee that
463** it will be invoked when there is lock contention.
464** If SQLite determines that invoking the busy handler could result in
465** a deadlock, it will return [SQLITE_BUSY] instead.
466** Consider a scenario where one process is holding a read lock that
467** it is trying to promote to a reserved lock and
468** a second process is holding a reserved lock that it is trying
469** to promote to an exclusive lock.  The first process cannot proceed
470** because it is blocked by the second and the second process cannot
471** proceed because it is blocked by the first.  If both processes
472** invoke the busy handlers, neither will make any progress.  Therefore,
473** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
474** will induce the first process to release its read lock and allow
475** the second process to proceed.
476**
477** The default busy callback is NULL.
478**
479** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] when
480** SQLite is in the middle of a large transaction where all the
481** changes will not fit into the in-memory cache.  SQLite will
482** already hold a RESERVED lock on the database file, but it needs
483** to promote this lock to EXCLUSIVE so that it can spill cache
484** pages into the database file without harm to concurrent
485** readers.  If it is unable to promote the lock, then the in-memory
486** cache will be left in an inconsistent state and so the error
487** code is promoted from the relatively benign [SQLITE_BUSY] to
488** the more severe [SQLITE_IOERR_BLOCKED].  This error code promotion
489** forces an automatic rollback of the changes. See the
490** <a href="http://www.sqlite.org/cvstrac/wiki?p=CorruptionFollowingBusyError">
491** CorruptionFollowingBusyError</a> wiki page for a discussion of why
492** this is important.
493**
494** Sqlite is re-entrant, so the busy handler may start a new query.
495** (It is not clear why anyone would every want to do this, but it
496** is allowed, in theory.)  But the busy handler may not close the
497** database.  Closing the database from a busy handler will delete
498** data structures out from under the executing query and will
499** probably result in a segmentation fault or other runtime error.
500**
501** There can only be a single busy handler defined for each database
502** connection.  Setting a new busy handler clears any previous one.
503** Note that calling [sqlite3_busy_timeout()] will also set or clear
504** the busy handler.
505*/
506int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
507
508/*
509** CAPI3REF: Set A Busy Timeout
510**
511** This routine sets a busy handler that sleeps for a while when a
512** table is locked.  The handler will sleep multiple times until
513** at least "ms" milliseconds of sleeping have been done.  After
514** "ms" milliseconds of sleeping, the handler returns 0 which
515** causes [sqlite3_step()] to return [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
516**
517** Calling this routine with an argument less than or equal to zero
518** turns off all busy handlers.
519**
520** There can only be a single busy handler for a particular database
521** connection.  If another busy handler was defined
522** (using [sqlite3_busy_handler()]) prior to calling
523** this routine, that other busy handler is cleared.
524*/
525int sqlite3_busy_timeout(sqlite3*, int ms);
526
527/*
528** CAPI3REF: Convenience Routines For Running Queries
529**
530** This next routine is a convenience wrapper around [sqlite3_exec()].
531** Instead of invoking a user-supplied callback for each row of the
532** result, this routine remembers each row of the result in memory
533** obtained from [sqlite3_malloc()], then returns all of the result after the
534** query has finished.
535**
536** As an example, suppose the query result where this table:
537**
538** <pre>
539**        Name        | Age
540**        -----------------------
541**        Alice       | 43
542**        Bob         | 28
543**        Cindy       | 21
544** </pre>
545**
546** If the 3rd argument were &azResult then after the function returns
547** azResult will contain the following data:
548**
549** <pre>
550**        azResult[0] = "Name";
551**        azResult[1] = "Age";
552**        azResult[2] = "Alice";
553**        azResult[3] = "43";
554**        azResult[4] = "Bob";
555**        azResult[5] = "28";
556**        azResult[6] = "Cindy";
557**        azResult[7] = "21";
558** </pre>
559**
560** Notice that there is an extra row of data containing the column
561** headers.  But the *nrow return value is still 3.  *ncolumn is
562** set to 2.  In general, the number of values inserted into azResult
563** will be ((*nrow) + 1)*(*ncolumn).
564**
565** After the calling function has finished using the result, it should
566** pass the result data pointer to sqlite3_free_table() in order to
567** release the memory that was malloc-ed.  Because of the way the
568** [sqlite3_malloc()] happens, the calling function must not try to call
569** [sqlite3_free()] directly.  Only [sqlite3_free_table()] is able to release
570** the memory properly and safely.
571**
572** The return value of this routine is the same as from [sqlite3_exec()].
573*/
574int sqlite3_get_table(
575  sqlite3*,              /* An open database */
576  const char *sql,       /* SQL to be executed */
577  char ***resultp,       /* Result written to a char *[]  that this points to */
578  int *nrow,             /* Number of result rows written here */
579  int *ncolumn,          /* Number of result columns written here */
580  char **errmsg          /* Error msg written here */
581);
582void sqlite3_free_table(char **result);
583
584/*
585** CAPI3REF: Formatted String Printing Functions
586**
587** These routines are workalikes of the "printf()" family of functions
588** from the standard C library.
589**
590** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
591** results into memory obtained from [sqlite_malloc()].
592** The strings returned by these two routines should be
593** released by [sqlite3_free()].  Both routines return a
594** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
595** memory to hold the resulting string.
596**
597** In sqlite3_snprintf() routine is similar to "snprintf()" from
598** the standard C library.  The result is written into the
599** buffer supplied as the second parameter whose size is given by
600** the first parameter.  Note that the order of the
601** first two parameters is reversed from snprintf().  This is an
602** historical accident that cannot be fixed without breaking
603** backwards compatibility.  Note also that sqlite3_snprintf()
604** returns a pointer to its buffer instead of the number of
605** characters actually written into the buffer.  We admit that
606** the number of characters written would be a more useful return
607** value but we cannot change the implementation of sqlite3_snprintf()
608** now without breaking compatibility.
609**
610** As long as the buffer size is greater than zero, sqlite3_snprintf()
611** guarantees that the buffer is always zero-terminated.  The first
612** parameter "n" is the total size of the buffer, including space for
613** the zero terminator.  So the longest string that can be completely
614** written will be n-1 characters.
615**
616** These routines all implement some additional formatting
617** options that are useful for constructing SQL statements.
618** All of the usual printf formatting options apply.  In addition, there
619** is are "%q" and "%Q" options.
620**
621** The %q option works like %s in that it substitutes a null-terminated
622** string from the argument list.  But %q also doubles every '\'' character.
623** %q is designed for use inside a string literal.  By doubling each '\''
624** character it escapes that character and allows it to be inserted into
625** the string.
626**
627** For example, so some string variable contains text as follows:
628**
629** <blockquote><pre>
630**  char *zText = "It's a happy day!";
631** </pre></blockquote>
632**
633** One can use this text in an SQL statement as follows:
634**
635** <blockquote><pre>
636**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
637**  sqlite3_exec(db, zSQL, 0, 0, 0);
638**  sqlite3_free(zSQL);
639** </pre></blockquote>
640**
641** Because the %q format string is used, the '\'' character in zText
642** is escaped and the SQL generated is as follows:
643**
644** <blockquote><pre>
645**  INSERT INTO table1 VALUES('It''s a happy day!')
646** </pre></blockquote>
647**
648** This is correct.  Had we used %s instead of %q, the generated SQL
649** would have looked like this:
650**
651** <blockquote><pre>
652**  INSERT INTO table1 VALUES('It's a happy day!');
653** </pre></blockquote>
654**
655** This second example is an SQL syntax error.  As a general rule you
656** should always use %q instead of %s when inserting text into a string
657** literal.
658**
659** The %Q option works like %q except it also adds single quotes around
660** the outside of the total string.  Or if the parameter in the argument
661** list is a NULL pointer, %Q substitutes the text "NULL" (without single
662** quotes) in place of the %Q option.  So, for example, one could say:
663**
664** <blockquote><pre>
665**  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
666**  sqlite3_exec(db, zSQL, 0, 0, 0);
667**  sqlite3_free(zSQL);
668** </pre></blockquote>
669**
670** The code above will render a correct SQL statement in the zSQL
671** variable even if the zText variable is a NULL pointer.
672*/
673char *sqlite3_mprintf(const char*,...);
674char *sqlite3_vmprintf(const char*, va_list);
675char *sqlite3_snprintf(int,char*,const char*, ...);
676
677/*
678** CAPI3REF: Memory Allocation Functions
679**
680** SQLite uses its own memory allocator.  On some installations, this
681** memory allocator is identical to the standard malloc()/realloc()/free()
682** and can be used interchangable.  On others, the implementations are
683** different.  For maximum portability, it is best not to mix calls
684** to the standard malloc/realloc/free with the sqlite versions.
685*/
686void *sqlite3_malloc(int);
687void *sqlite3_realloc(void*, int);
688void sqlite3_free(void*);
689
690/*
691** CAPI3REF: Compile-Time Authorization Callbacks
692***
693** This routine registers a authorizer callback with the SQLite library.
694** The authorizer callback is invoked as SQL statements are being compiled
695** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
696** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  At various
697** points during the compilation process, as logic is being created
698** to perform various actions, the authorizer callback is invoked to
699** see if those actions are allowed.  The authorizer callback should
700** return SQLITE_OK to allow the action, [SQLITE_IGNORE] to disallow the
701** specific action but allow the SQL statement to continue to be
702** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
703** rejected with an error.
704**
705** Depending on the action, the [SQLITE_IGNORE] and [SQLITE_DENY] return
706** codes might mean something different or they might mean the same
707** thing.  If the action is, for example, to perform a delete opertion,
708** then [SQLITE_IGNORE] and [SQLITE_DENY] both cause the statement compilation
709** to fail with an error.  But if the action is to read a specific column
710** from a specific table, then [SQLITE_DENY] will cause the entire
711** statement to fail but [SQLITE_IGNORE] will cause a NULL value to be
712** read instead of the actual column value.
713**
714** The first parameter to the authorizer callback is a copy of
715** the third parameter to the sqlite3_set_authorizer() interface.
716** The second parameter to the callback is an integer
717** [SQLITE_COPY | action code] that specifies the particular action
718** to be authorized.  The available action codes are
719** [SQLITE_COPY | documented separately].  The third through sixth
720** parameters to the callback are strings that contain additional
721** details about the action to be authorized.
722**
723** An authorizer is used when preparing SQL statements from an untrusted
724** source, to ensure that the SQL statements do not try to access data
725** that they are not allowed to see, or that they do not try to
726** execute malicious statements that damage the database.  For
727** example, an application may allow a user to enter arbitrary
728** SQL queries for evaluation by a database.  But the application does
729** not want the user to be able to make arbitrary changes to the
730** database.  An authorizer could then be put in place while the
731** user-entered SQL is being prepared that disallows everything
732** except SELECT statements.
733**
734** Only a single authorizer can be in place on a database connection
735** at a time.  Each call to sqlite3_set_authorizer overrides the
736** previous call.  A NULL authorizer means that no authorization
737** callback is invoked.  The default authorizer is NULL.
738**
739** Note that the authorizer callback is invoked only during
740** [sqlite3_prepare()] or its variants.  Authorization is not
741** performed during statement evaluation in [sqlite3_step()].
742*/
743int sqlite3_set_authorizer(
744  sqlite3*,
745  int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
746  void *pUserData
747);
748
749/*
750** CAPI3REF: Authorizer Return Codes
751**
752** The [sqlite3_set_authorizer | authorizer callback function] must
753** return either [SQLITE_OK] or one of these two constants in order
754** to signal SQLite whether or not the action is permitted.  See the
755** [sqlite3_set_authorizer | authorizer documentation] for additional
756** information.
757*/
758#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
759#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
760
761/*
762** CAPI3REF: Authorizer Action Codes
763**
764** The [sqlite3_set_authorizer()] interface registers a callback function
765** that is invoked to authorizer certain SQL statement actions.  The
766** second parameter to the callback is an integer code that specifies
767** what action is being authorized.  These are the integer action codes that
768** the authorizer callback may be passed.
769**
770** These action code values signify what kind of operation is to be
771** authorized.  The 3rd and 4th parameters to the authorization callback
772** function will be parameters or NULL depending on which of these
773** codes is used as the second parameter.  The 5th parameter to the
774** authorizer callback is the name of the database ("main", "temp",
775** etc.) if applicable.  The 6th parameter to the authorizer callback
776** is the name of the inner-most trigger or view that is responsible for
777** the access attempt or NULL if this access attempt is directly from
778** top-level SQL code.
779*/
780/******************************************* 3rd ************ 4th ***********/
781#define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
782#define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
783#define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
784#define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
785#define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
786#define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
787#define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
788#define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
789#define SQLITE_DELETE                9   /* Table Name      NULL            */
790#define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
791#define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
792#define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
793#define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
794#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
795#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
796#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
797#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
798#define SQLITE_INSERT               18   /* Table Name      NULL            */
799#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
800#define SQLITE_READ                 20   /* Table Name      Column Name     */
801#define SQLITE_SELECT               21   /* NULL            NULL            */
802#define SQLITE_TRANSACTION          22   /* NULL            NULL            */
803#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
804#define SQLITE_ATTACH               24   /* Filename        NULL            */
805#define SQLITE_DETACH               25   /* Database Name   NULL            */
806#define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
807#define SQLITE_REINDEX              27   /* Index Name      NULL            */
808#define SQLITE_ANALYZE              28   /* Table Name      NULL            */
809#define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
810#define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
811#define SQLITE_FUNCTION             31   /* Function Name   NULL            */
812#define SQLITE_COPY                  0   /* No longer used */
813
814/*
815** CAPI3REF: Tracing And Profiling Functions
816**
817** These routines register callback functions that can be used for
818** tracing and profiling the execution of SQL statements.
819** The callback function registered by sqlite3_trace() is invoked
820** at the first [sqlite3_step()] for the evaluation of an SQL statement.
821** The callback function registered by sqlite3_profile() is invoked
822** as each SQL statement finishes and includes
823** information on how long that statement ran.
824**
825** The sqlite3_profile() API is currently considered experimental and
826** is subject to change.
827*/
828void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
829void *sqlite3_profile(sqlite3*,
830   void(*xProfile)(void*,const char*,sqlite_uint64), void*);
831
832/*
833** CAPI3REF: Query Progress Callbacks
834**
835** This routine configures a callback function - the progress callback - that
836** is invoked periodically during long running calls to [sqlite3_exec()],
837** [sqlite3_step()] and [sqlite3_get_table()].  An example use for this
838** interface is to keep a GUI updated during a large query.
839**
840** The progress callback is invoked once for every N virtual machine opcodes,
841** where N is the second argument to this function. The progress callback
842** itself is identified by the third argument to this function. The fourth
843** argument to this function is a void pointer passed to the progress callback
844** function each time it is invoked.
845**
846** If a call to [sqlite3_exec()], [sqlite3_step()], or [sqlite3_get_table()]
847** results in fewer than N opcodes being executed, then the progress
848** callback is never invoked.
849**
850** Only a single progress callback function may be registered for each
851** open database connection.  Every call to sqlite3_progress_handler()
852** overwrites the results of the previous call.
853** To remove the progress callback altogether, pass NULL as the third
854** argument to this function.
855**
856** If the progress callback returns a result other than 0, then the current
857** query is immediately terminated and any database changes rolled back.
858** The containing [sqlite3_exec()], [sqlite3_step()], or
859** [sqlite3_get_table()] call returns SQLITE_INTERRUPT.   This feature
860** can be used, for example, to implement the "Cancel" button on a
861** progress dialog box in a GUI.
862*/
863void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
864
865/*
866** CAPI3REF: Opening A New Database Connection
867**
868** Open the sqlite database file "filename".  The "filename" is UTF-8
869** encoded for sqlite3_open() and UTF-16 encoded in the native byte order
870** for sqlite3_open16().  An [sqlite3*] handle is returned in *ppDb, even
871** if an error occurs. If the database is opened (or created) successfully,
872** then SQLITE_OK is returned. Otherwise an error code is returned. The
873** sqlite3_errmsg() or sqlite3_errmsg16()  routines can be used to obtain
874** an English language description of the error.
875**
876** If the database file does not exist, then a new database will be created
877** as needed.  The default encoding for the database will be UTF-8 if
878** sqlite3_open() is called and UTF-16 if sqlite3_open16 is used.
879**
880** Whether or not an error occurs when it is opened, resources associated
881** with the [sqlite3*] handle should be released by passing it to
882** sqlite3_close() when it is no longer required.
883**
884** Note to windows users:  The encoding used for the filename argument
885** of sqlite3_open() must be UTF-8, not whatever codepage is currently
886** defined.  Filenames containing international characters must be converted
887** to UTF-8 prior to passing them into sqlite3_open().
888*/
889int sqlite3_open(
890  const char *filename,   /* Database filename (UTF-8) */
891  sqlite3 **ppDb          /* OUT: SQLite db handle */
892);
893int sqlite3_open16(
894  const void *filename,   /* Database filename (UTF-16) */
895  sqlite3 **ppDb          /* OUT: SQLite db handle */
896);
897
898/*
899** CAPI3REF: Error Codes And Messages
900**
901** The sqlite3_errcode() interface returns the numeric
902** [SQLITE_OK | result code] or [SQLITE_IOERR_READ | extended result code]
903** for the most recent failed sqlite3_* API call associated
904** with [sqlite3] handle 'db'.  If a prior API call failed but the
905** most recent API call succeeded, the return value from sqlite3_errcode()
906** is undefined.
907**
908** The sqlite3_errmsg() and sqlite3_errmsg16() return English-langauge
909** text that describes the error, as either UTF8 or UTF16 respectively.
910** Memory to hold the error message string is managed internally.  The
911** string may be overwritten or deallocated by subsequent calls to SQLite
912** interface functions.
913**
914** Calls to many sqlite3_* functions set the error code and string returned
915** by [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()]
916** (overwriting the previous values). Note that calls to [sqlite3_errcode()],
917** [sqlite3_errmsg()], and [sqlite3_errmsg16()] themselves do not affect the
918** results of future invocations.  Calls to API routines that do not return
919** an error code (examples: [sqlite3_data_count()] or [sqlite3_mprintf()]) do
920** not change the error code returned by this routine.
921**
922** Assuming no other intervening sqlite3_* API calls are made, the error
923** code returned by this function is associated with the same error as
924** the strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()].
925*/
926int sqlite3_errcode(sqlite3 *db);
927const char *sqlite3_errmsg(sqlite3*);
928const void *sqlite3_errmsg16(sqlite3*);
929
930/*
931** CAPI3REF: SQL Statement Object
932**
933** Instance of this object represent single SQL statements.  This
934** is variously known as a "prepared statement" or a
935** "compiled SQL statement" or simply as a "statement".
936**
937** The life of a statement object goes something like this:
938**
939** <ol>
940** <li> Create the object using [sqlite3_prepare_v2()] or a related
941**      function.
942** <li> Bind values to host parameters using
943**      [sqlite3_bind_blob | sqlite3_bind_* interfaces].
944** <li> Run the SQL by calling [sqlite3_step()] one or more times.
945** <li> Reset the statement using [sqlite3_reset()] then go back
946**      to step 2.  Do this zero or more times.
947** <li> Destroy the object using [sqlite3_finalize()].
948** </ol>
949**
950** Refer to documentation on individual methods above for additional
951** information.
952*/
953typedef struct sqlite3_stmt sqlite3_stmt;
954
955/*
956** CAPI3REF: Compiling An SQL Statement
957**
958** To execute an SQL query, it must first be compiled into a byte-code
959** program using one of these routines.
960**
961** The first argument "db" is an [sqlite3 | SQLite database handle]
962** obtained from a prior call to [sqlite3_open()] or [sqlite3_open16()].
963** The second argument "zSql" is the statement to be compiled, encoded
964** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
965** interfaces uses UTF-8 and sqlite3_prepare16() and sqlite3_prepare16_v2()
966** use UTF-16. If the next argument, "nBytes", is less
967** than zero, then zSql is read up to the first zero terminator.  If
968** "nBytes" is not less than zero, then it is the length of the string zSql
969** in bytes (not characters).
970**
971** *pzTail is made to point to the first byte past the end of the first
972** SQL statement in zSql.  This routine only compiles the first statement
973** in zSql, so *pzTail is left pointing to what remains uncompiled.
974**
975** *ppStmt is left pointing to a compiled
976** [sqlite3_stmt | SQL statement structure] that can be
977** executed using [sqlite3_step()].  Or if there is an error, *ppStmt may be
978** set to NULL.  If the input text contained no SQL (if the input is and
979** empty string or a comment) then *ppStmt is set to NULL.  The calling
980** procedure is responsible for deleting the compiled SQL statement
981** using [sqlite3_finalize()] after it has finished with it.
982**
983** On success, [SQLITE_OK] is returned.  Otherwise an
984** [SQLITE_ERROR | error code] is returned.
985**
986** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
987** recommended for all new programs. The two older interfaces are retained
988** for backwards compatibility, but their use is discouraged.
989** In the "v2" interfaces, the prepared statement
990** that is returned (the [sqlite3_stmt] object) contains a copy of the
991** original SQL text. This causes the [sqlite3_step()] interface to
992** behave a differently in two ways:
993**
994** <ol>
995** <li>
996** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
997** always used to do, [sqlite3_step()] will automatically recompile the SQL
998** statement and try to run it again.  If the schema has changed in a way
999** that makes the statement no longer valid, [sqlite3_step()] will still
1000** return [SQLITE_SCHEMA].  But unlike the legacy behavior, [SQLITE_SCHEMA] is
1001** now a fatal error.  Calling [sqlite3_prepare_v2()] again will not make the
1002** error go away.  Note: use [sqlite3_errmsg()] to find the text of the parsing
1003** error that results in an [SQLITE_SCHEMA] return.
1004** </li>
1005**
1006** <li>
1007** When an error occurs,
1008** [sqlite3_step()] will return one of the detailed
1009** [SQLITE_ERROR | result codes] or
1010** [SQLITE_IOERR_READ | extended result codes] such as directly.
1011** The legacy behavior was that [sqlite3_step()] would only return a generic
1012** [SQLITE_ERROR] result code and you would have to make a second call to
1013** [sqlite3_reset()] in order to find the underlying cause of the problem.
1014** With the "v2" prepare interfaces, the underlying reason for the error is
1015** returned immediately.
1016** </li>
1017** </ol>
1018*/
1019int sqlite3_prepare(
1020  sqlite3 *db,            /* Database handle */
1021  const char *zSql,       /* SQL statement, UTF-8 encoded */
1022  int nBytes,             /* Length of zSql in bytes. */
1023  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
1024  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
1025);
1026int sqlite3_prepare_v2(
1027  sqlite3 *db,            /* Database handle */
1028  const char *zSql,       /* SQL statement, UTF-8 encoded */
1029  int nBytes,             /* Length of zSql in bytes. */
1030  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
1031  const char **pzTail     /* OUT: Pointer to unused portion of zSql */
1032);
1033int sqlite3_prepare16(
1034  sqlite3 *db,            /* Database handle */
1035  const void *zSql,       /* SQL statement, UTF-16 encoded */
1036  int nBytes,             /* Length of zSql in bytes. */
1037  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
1038  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
1039);
1040int sqlite3_prepare16_v2(
1041  sqlite3 *db,            /* Database handle */
1042  const void *zSql,       /* SQL statement, UTF-16 encoded */
1043  int nBytes,             /* Length of zSql in bytes. */
1044  sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
1045  const void **pzTail     /* OUT: Pointer to unused portion of zSql */
1046);
1047
1048/*
1049** CAPI3REF:  Dynamically Typed Value Object
1050**
1051** SQLite uses dynamic typing for the values it stores.  Values can
1052** be integers, floating point values, strings, BLOBs, or NULL.  When
1053** passing around values internally, each value is represented as
1054** an instance of the sqlite3_value object.
1055*/
1056typedef struct Mem sqlite3_value;
1057
1058/*
1059** CAPI3REF:  SQL Function Context Object
1060**
1061** The context in which an SQL function executes is stored in an
1062** sqlite3_context object.  A pointer to such an object is the
1063** first parameter to user-defined SQL functions.
1064*/
1065typedef struct sqlite3_context sqlite3_context;
1066
1067/*
1068** CAPI3REF:  Binding Values To Prepared Statements
1069**
1070** In the SQL strings input to [sqlite3_prepare_v2()] and its variants,
1071** one or more literals can be replace by a parameter in one of these
1072** forms:
1073**
1074** <ul>
1075** <li>  ?
1076** <li>  ?NNN
1077** <li>  :AAA
1078** <li>  @AAA
1079** <li>  $VVV
1080** </ul>
1081**
1082** In the parameter forms shown above NNN is an integer literal,
1083** AAA is an alphanumeric identifier and VVV is a variable name according
1084** to the syntax rules of the TCL programming language.
1085** The values of these parameters (also called "host parameter names")
1086** can be set using the sqlite3_bind_*() routines defined here.
1087**
1088** The first argument to the sqlite3_bind_*() routines always is a pointer
1089** to the [sqlite3_stmt] object returned from [sqlite3_prepare_v2()] or
1090** its variants.  The second
1091** argument is the index of the parameter to be set.  The first parameter has
1092** an index of 1. When the same named parameter is used more than once, second
1093** and subsequent
1094** occurrences have the same index as the first occurrence.  The index for
1095** named parameters can be looked up using the
1096** [sqlite3_bind_parameter_name()] API if desired.  The index for "?NNN"
1097** parametes is the value of NNN.
1098** The NNN value must be between 1 and the compile-time
1099** parameter SQLITE_MAX_VARIABLE_NUMBER (default value: 999).
1100** See <a href="limits.html">limits.html</a> for additional information.
1101**
1102** The third argument is the value to bind to the parameter.
1103**
1104** In those
1105** routines that have a fourth argument, its value is the number of bytes
1106** in the parameter.  To be clear: the value is the number of bytes in the
1107** string, not the number of characters.  The number
1108** of bytes does not include the zero-terminator at the end of strings.
1109** If the fourth parameter is negative, the length of the string is
1110** number of bytes up to the first zero terminator.
1111**
1112** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
1113** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
1114** text after SQLite has finished with it.  If the fifth argument is the
1115** special value [SQLITE_STATIC], then the library assumes that the information
1116** is in static, unmanaged space and does not need to be freed.  If the
1117** fifth argument has the value [SQLITE_TRANSIENT], then SQLite makes its
1118** own private copy of the data immediately, before the sqlite3_bind_*()
1119** routine returns.
1120**
1121** The sqlite3_bind_zeroblob() routine binds a BLOB of length n that
1122** is filled with zeros.  A zeroblob uses a fixed amount of memory
1123** (just an integer to hold it size) while it is being processed.
1124** Zeroblobs are intended to serve as place-holders for BLOBs whose
1125** content is later written using
1126** [sqlite3_blob_open | increment BLOB I/O] routines.
1127**
1128** The sqlite3_bind_*() routines must be called after
1129** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and
1130** before [sqlite3_step()].
1131** Bindings are not cleared by the [sqlite3_reset()] routine.
1132** Unbound parameters are interpreted as NULL.
1133**
1134** These routines return [SQLITE_OK] on success or an error code if
1135** anything goes wrong.  [SQLITE_RANGE] is returned if the parameter
1136** index is out of range.  [SQLITE_NOMEM] is returned if malloc fails.
1137** [SQLITE_MISUSE] is returned if these routines are called on a virtual
1138** machine that is the wrong state or which has already been finalized.
1139*/
1140int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
1141int sqlite3_bind_double(sqlite3_stmt*, int, double);
1142int sqlite3_bind_int(sqlite3_stmt*, int, int);
1143int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite_int64);
1144int sqlite3_bind_null(sqlite3_stmt*, int);
1145int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
1146int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
1147int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
1148int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
1149
1150/*
1151** CAPI3REF: Number Of Host Parameters
1152**
1153** Return the largest host parameter index in the precompiled statement given
1154** as the argument.  When the host parameters are of the forms like ":AAA"
1155** or "?", then they are assigned sequential increasing numbers beginning
1156** with one, so the value returned is the number of parameters.  However
1157** if the same host parameter name is used multiple times, each occurrance
1158** is given the same number, so the value returned in that case is the number
1159** of unique host parameter names.  If host parameters of the form "?NNN"
1160** are used (where NNN is an integer) then there might be gaps in the
1161** numbering and the value returned by this interface is the index of the
1162** host parameter with the largest index value.
1163*/
1164int sqlite3_bind_parameter_count(sqlite3_stmt*);
1165
1166/*
1167** CAPI3REF: Name Of A Host Parameter
1168**
1169** This routine returns a pointer to the name of the n-th parameter in a
1170** [sqlite3_stmt | prepared statement].
1171** Host parameters of the form ":AAA" or "@AAA" or "$VVV" have a name
1172** which is the string ":AAA" or "@AAA" or "$VVV".
1173** In other words, the initial ":" or "$" or "@"
1174** is included as part of the name.
1175** Parameters of the form "?" or "?NNN" have no name.
1176**
1177** The first bound parameter has an index of 1, not 0.
1178**
1179** If the value n is out of range or if the n-th parameter is nameless,
1180** then NULL is returned.  The returned string is always in the
1181** UTF-8 encoding even if the named parameter was originally specified
1182** as UTF-16 in [sqlite3_prepare16()] or [sqlite3_prepare16_v2()].
1183*/
1184const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
1185
1186/*
1187** CAPI3REF: Index Of A Parameter With A Given Name
1188**
1189** This routine returns the index of a host parameter with the given name.
1190** The name must match exactly.  If no parameter with the given name is
1191** found, return 0.  Parameter names must be UTF8.
1192*/
1193int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
1194
1195/*
1196** CAPI3REF: Reset All Bindings On A Prepared Statement
1197**
1198** Contrary to the intuition of many, [sqlite3_reset()] does not
1199** reset the [sqlite3_bind_blob | bindings] on a
1200** [sqlite3_stmt | prepared statement].  Use this routine to
1201** reset all host parameters to NULL.
1202*/
1203int sqlite3_clear_bindings(sqlite3_stmt*);
1204
1205/*
1206** CAPI3REF: Number Of Columns In A Result Set
1207**
1208** Return the number of columns in the result set returned by the
1209** [sqlite3_stmt | compiled SQL statement]. This routine returns 0
1210** if pStmt is an SQL statement that does not return data (for
1211** example an UPDATE).
1212*/
1213int sqlite3_column_count(sqlite3_stmt *pStmt);
1214
1215/*
1216** CAPI3REF: Column Names In A Result Set
1217**
1218** These routines return the name assigned to a particular column
1219** in the result set of a SELECT statement.  The sqlite3_column_name()
1220** interface returns a pointer to a UTF8 string and sqlite3_column_name16()
1221** returns a pointer to a UTF16 string.  The first parameter is the
1222** [sqlite_stmt | prepared statement] that implements the SELECT statement.
1223** The second parameter is the column number.  The left-most column is
1224** number 0.
1225**
1226** The returned string pointer is valid until either the
1227** [sqlite_stmt | prepared statement] is destroyed by [sqlite3_finalize()]
1228** or until the next call sqlite3_column_name() or sqlite3_column_name16()
1229** on the same column.
1230*/
1231const char *sqlite3_column_name(sqlite3_stmt*, int N);
1232const void *sqlite3_column_name16(sqlite3_stmt*, int N);
1233
1234/*
1235** CAPI3REF: Source Of Data In A Query Result
1236**
1237** These routines provide a means to determine what column of what
1238** table in which database a result of a SELECT statement comes from.
1239** The name of the database or table or column can be returned as
1240** either a UTF8 or UTF16 string.  The _database_ routines return
1241** the database name, the _table_ routines return the table name, and
1242** the origin_ routines return the column name.
1243** The returned string is valid until
1244** the [sqlite3_stmt | prepared statement] is destroyed using
1245** [sqlite3_finalize()] or until the same information is requested
1246** again in a different encoding.
1247**
1248** The names returned are the original un-aliased names of the
1249** database, table, and column.
1250**
1251** The first argument to the following calls is a
1252** [sqlite3_stmt | compiled SQL statement].
1253** These functions return information about the Nth column returned by
1254** the statement, where N is the second function argument.
1255**
1256** If the Nth column returned by the statement is an expression
1257** or subquery and is not a column value, then all of these functions
1258** return NULL. Otherwise, they return the
1259** name of the attached database, table and column that query result
1260** column was extracted from.
1261**
1262** As with all other SQLite APIs, those postfixed with "16" return UTF-16
1263** encoded strings, the other functions return UTF-8.
1264**
1265** These APIs are only available if the library was compiled with the
1266** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
1267*/
1268const char *sqlite3_column_database_name(sqlite3_stmt*,int);
1269const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
1270const char *sqlite3_column_table_name(sqlite3_stmt*,int);
1271const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
1272const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
1273const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
1274
1275/*
1276** CAPI3REF: Declared Datatype Of A Query Result
1277**
1278** The first parameter is a [sqlite3_stmt | compiled SQL statement].
1279** If this statement is a SELECT statement and the Nth column of the
1280** returned result set  of that SELECT is a table column (not an
1281** expression or subquery) then the declared type of the table
1282** column is returned. If the Nth column of the result set is an
1283** expression or subquery, then a NULL pointer is returned.
1284** The returned string is always UTF-8 encoded. For example, in
1285** the database schema:
1286**
1287** CREATE TABLE t1(c1 VARIANT);
1288**
1289** And the following statement compiled:
1290**
1291** SELECT c1 + 1, c1 FROM t1;
1292**
1293** Then this routine would return the string "VARIANT" for the second
1294** result column (i==1), and a NULL pointer for the first result column
1295** (i==0).
1296**
1297** SQLite uses dynamic run-time typing.  So just because a column
1298** is declared to contain a particular type does not mean that the
1299** data stored in that column is of the declared type.  SQLite is
1300** strongly typed, but the typing is dynamic not static.  Type
1301** is associated with individual values, not with the containers
1302** used to hold those values.
1303*/
1304const char *sqlite3_column_decltype(sqlite3_stmt *, int i);
1305const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
1306
1307/*
1308** CAPI3REF:  Evaluate An SQL Statement
1309**
1310** After an [sqlite3_stmt | SQL statement] has been prepared with a call
1311** to either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or to one of
1312** the legacy interfaces [sqlite3_prepare()] or [sqlite3_prepare16()],
1313** then this function must be called one or more times to evaluate the
1314** statement.
1315**
1316** The details of the behavior of this sqlite3_step() interface depend
1317** on whether the statement was prepared using the newer "v2" interface
1318** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
1319** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
1320** new "v2" interface is recommended for new applications but the legacy
1321** interface will continue to be supported.
1322**
1323** In the lagacy interface, the return value will be either [SQLITE_BUSY],
1324** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
1325** With the "v2" interface, any of the other [SQLITE_OK | result code]
1326** or [SQLITE_IOERR_READ | extended result code] might be returned as
1327** well.
1328**
1329** [SQLITE_BUSY] means that the database engine was unable to acquire the
1330** database locks it needs to do its job.  If the statement is a COMMIT
1331** or occurs outside of an explicit transaction, then you can retry the
1332** statement.  If the statement is not a COMMIT and occurs within a
1333** explicit transaction then you should rollback the transaction before
1334** continuing.
1335**
1336** [SQLITE_DONE] means that the statement has finished executing
1337** successfully.  sqlite3_step() should not be called again on this virtual
1338** machine without first calling [sqlite3_reset()] to reset the virtual
1339** machine back to its initial state.
1340**
1341** If the SQL statement being executed returns any data, then
1342** [SQLITE_ROW] is returned each time a new row of data is ready
1343** for processing by the caller. The values may be accessed using
1344** the [sqlite3_column_int | column access functions].
1345** sqlite3_step() is called again to retrieve the next row of data.
1346**
1347** [SQLITE_ERROR] means that a run-time error (such as a constraint
1348** violation) has occurred.  sqlite3_step() should not be called again on
1349** the VM. More information may be found by calling [sqlite3_errmsg()].
1350** With the legacy interface, a more specific error code (example:
1351** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
1352** can be obtained by calling [sqlite3_reset()] on the
1353** [sqlite_stmt | prepared statement].  In the "v2" interface,
1354** the more specific error code is returned directly by sqlite3_step().
1355**
1356** [SQLITE_MISUSE] means that the this routine was called inappropriately.
1357** Perhaps it was called on a [sqlite_stmt | prepared statement] that has
1358** already been [sqlite3_finalize | finalized] or on one that had
1359** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
1360** be the case that the same database connection is being used by two or
1361** more threads at the same moment in time.
1362**
1363** <b>Goofy Interface Alert:</b>
1364** In the legacy interface,
1365** the sqlite3_step() API always returns a generic error code,
1366** [SQLITE_ERROR], following any error other than [SQLITE_BUSY]
1367** and [SQLITE_MISUSE].  You must call [sqlite3_reset()] or
1368** [sqlite3_finalize()] in order to find one of the specific
1369** [SQLITE_ERROR | result codes] that better describes the error.
1370** We admit that this is a goofy design.  The problem has been fixed
1371** with the "v2" interface.  If you prepare all of your SQL statements
1372** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
1373** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()], then the
1374** more specific [SQLITE_ERROR | result codes] are returned directly
1375** by sqlite3_step().  The use of the "v2" interface is recommended.
1376*/
1377int sqlite3_step(sqlite3_stmt*);
1378
1379/*
1380** CAPI3REF:
1381**
1382** Return the number of values in the current row of the result set.
1383**
1384** After a call to [sqlite3_step()] that returns [SQLITE_ROW], this routine
1385** will return the same value as the [sqlite3_column_count()] function.
1386** After [sqlite3_step()] has returned an [SQLITE_DONE], [SQLITE_BUSY], or
1387** a [SQLITE_ERROR | error code], or before [sqlite3_step()] has been
1388** called on the [sqlite_stmt | prepared statement] for the first time,
1389** this routine returns zero.
1390*/
1391int sqlite3_data_count(sqlite3_stmt *pStmt);
1392
1393/*
1394** CAPI3REF: Fundamental Datatypes
1395**
1396** Every value in SQLite has one of five fundamental datatypes:
1397**
1398** <ul>
1399** <li> 64-bit signed integer
1400** <li> 64-bit IEEE floating point number
1401** <li> string
1402** <li> BLOB
1403** <li> NULL
1404** </ul>
1405**
1406** These constants are codes for each of those types.
1407**
1408** Note that the SQLITE_TEXT constant was also used in SQLite version 2
1409** for a completely different meaning.  Software that links against both
1410** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT not
1411** SQLITE_TEXT.
1412*/
1413#define SQLITE_INTEGER  1
1414#define SQLITE_FLOAT    2
1415#define SQLITE_BLOB     4
1416#define SQLITE_NULL     5
1417#ifdef SQLITE_TEXT
1418# undef SQLITE_TEXT
1419#else
1420# define SQLITE_TEXT     3
1421#endif
1422#define SQLITE3_TEXT     3
1423
1424/*
1425** CAPI3REF: Results Values From A Query
1426**
1427** These routines return information about the information
1428** in a single column of the current result row of a query.  In every
1429** case the first argument is a pointer to the
1430** [sqlite3_stmt | SQL statement] that is being
1431** evaluate (the [sqlite_stmt*] that was returned from
1432** [sqlite3_prepare_v2()] or one of its variants) and
1433** the second argument is the index of the column for which information
1434** should be returned.  The left-most column has an index of 0.
1435**
1436** If the SQL statement is not currently point to a valid row, or if the
1437** the column index is out of range, the result is undefined.
1438**
1439** The sqlite3_column_type() routine returns
1440** [SQLITE_INTEGER | datatype code] for the initial data type
1441** of the result column.  The returned value is one of [SQLITE_INTEGER],
1442** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
1443** returned by sqlite3_column_type() is only meaningful if no type
1444** conversions have occurred as described below.  After a type conversion,
1445** the value returned by sqlite3_column_type() is undefined.  Future
1446** versions of SQLite may change the behavior of sqlite3_column_type()
1447** following a type conversion.
1448**
1449** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
1450** routine returns the number of bytes in that BLOB or string.
1451** If the result is a UTF-16 string, then sqlite3_column_bytes() converts
1452** the string to UTF-8 and then returns the number of bytes.
1453** If the result is a numeric value then sqlite3_column_bytes() uses
1454** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
1455** the number of bytes in that string.
1456** The value returned does not include the zero terminator at the end
1457** of the string.  For clarity: the value returned is the number of
1458** bytes in the string, not the number of characters.
1459**
1460** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()
1461** but leaves the result in UTF-16 instead of UTF-8.
1462** The zero terminator is not included in this count.
1463**
1464** These routines attempt to convert the value where appropriate.  For
1465** example, if the internal representation is FLOAT and a text result
1466** is requested, [sqlite3_snprintf()] is used internally to do the conversion
1467** automatically.  The following table details the conversions that
1468** are applied:
1469**
1470** <blockquote>
1471** <table border="1">
1472** <tr><th> Internal <th> Requested <th>
1473** <tr><th>  Type    <th>    Type   <th> Conversion
1474**
1475** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
1476** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
1477** <tr><td>  NULL    <td>   TEXT    <td> Result is NULL pointer
1478** <tr><td>  NULL    <td>   BLOB    <td> Result is NULL pointer
1479** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
1480** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
1481** <tr><td> INTEGER  <td>   BLOB    <td> Same as for INTEGER->TEXT
1482** <tr><td>  FLOAT   <td> INTEGER   <td> Convert from float to integer
1483** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
1484** <tr><td>  FLOAT   <td>   BLOB    <td> Same as FLOAT->TEXT
1485** <tr><td>  TEXT    <td> INTEGER   <td> Use atoi()
1486** <tr><td>  TEXT    <td>  FLOAT    <td> Use atof()
1487** <tr><td>  TEXT    <td>   BLOB    <td> No change
1488** <tr><td>  BLOB    <td> INTEGER   <td> Convert to TEXT then use atoi()
1489** <tr><td>  BLOB    <td>  FLOAT    <td> Convert to TEXT then use atof()
1490** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
1491** </table>
1492** </blockquote>
1493**
1494** The table above makes reference to standard C library functions atoi()
1495** and atof().  SQLite does not really use these functions.  It has its
1496** on equavalent internal routines.  The atoi() and atof() names are
1497** used in the table for brevity and because they are familiar to most
1498** C programmers.
1499**
1500** Note that when type conversions occur, pointers returned by prior
1501** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
1502** sqlite3_column_text16() may be invalidated.
1503** Type conversions and pointer invalidations might occur
1504** in the following cases:
1505**
1506** <ul>
1507** <li><p>  The initial content is a BLOB and sqlite3_column_text()
1508**          or sqlite3_column_text16() is called.  A zero-terminator might
1509**          need to be added to the string.</p></li>
1510**
1511** <li><p>  The initial content is UTF-8 text and sqlite3_column_bytes16() or
1512**          sqlite3_column_text16() is called.  The content must be converted
1513**          to UTF-16.</p></li>
1514**
1515** <li><p>  The initial content is UTF-16 text and sqlite3_column_bytes() or
1516**          sqlite3_column_text() is called.  The content must be converted
1517**          to UTF-8.</p></li>
1518** </ul>
1519**
1520** Conversions between UTF-16be and UTF-16le are always done in place and do
1521** not invalidate a prior pointer, though of course the content of the buffer
1522** that the prior pointer points to will have been modified.  Other kinds
1523** of conversion are done in place when it is possible, but sometime it is
1524** not possible and in those cases prior pointers are invalidated.
1525**
1526** The safest and easiest to remember policy is to invoke these routines
1527** in one of the following ways:
1528**
1529**  <ul>
1530**  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
1531**  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
1532**  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
1533**  </ul>
1534**
1535** In other words, you should call sqlite3_column_text(), sqlite3_column_blob(),
1536** or sqlite3_column_text16() first to force the result into the desired
1537** format, then invoke sqlite3_column_bytes() or sqlite3_column_bytes16() to
1538** find the size of the result.  Do not mix call to sqlite3_column_text() or
1539** sqlite3_column_blob() with calls to sqlite3_column_bytes16().  And do not
1540** mix calls to sqlite3_column_text16() with calls to sqlite3_column_bytes().
1541*/
1542const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
1543int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
1544int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
1545double sqlite3_column_double(sqlite3_stmt*, int iCol);
1546int sqlite3_column_int(sqlite3_stmt*, int iCol);
1547sqlite_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
1548const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
1549const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
1550int sqlite3_column_type(sqlite3_stmt*, int iCol);
1551sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
1552
1553/*
1554** CAPI3REF: Destroy A Prepared Statement Object
1555**
1556** The sqlite3_finalize() function is called to delete a
1557** [sqlite3_stmt | compiled SQL statement]. If the statement was
1558** executed successfully, or not executed at all, then SQLITE_OK is returned.
1559** If execution of the statement failed then an
1560** [SQLITE_ERROR | error code] or [SQLITE_IOERR_READ | extended error code]
1561** is returned.
1562**
1563** This routine can be called at any point during the execution of the
1564** [sqlite3_stmt | virtual machine].  If the virtual machine has not
1565** completed execution when this routine is called, that is like
1566** encountering an error or an interrupt.  (See [sqlite3_interrupt()].)
1567** Incomplete updates may be rolled back and transactions cancelled,
1568** depending on the circumstances, and the
1569** [SQLITE_ERROR | result code] returned will be [SQLITE_ABORT].
1570*/
1571int sqlite3_finalize(sqlite3_stmt *pStmt);
1572
1573/*
1574** CAPI3REF: Reset A Prepared Statement Object
1575**
1576** The sqlite3_reset() function is called to reset a
1577** [sqlite_stmt | compiled SQL statement] object.
1578** back to it's initial state, ready to be re-executed.
1579** Any SQL statement variables that had values bound to them using
1580** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
1581** Use [sqlite3_clear_bindings()] to reset the bindings.
1582*/
1583int sqlite3_reset(sqlite3_stmt *pStmt);
1584
1585/*
1586** CAPI3REF: Create Or Redefine SQL Functions
1587**
1588** The following two functions are used to add SQL functions or aggregates
1589** or to redefine the behavior of existing SQL functions or aggregates.  The
1590** difference only between the two is that the second parameter, the
1591** name of the (scalar) function or aggregate, is encoded in UTF-8 for
1592** sqlite3_create_function() and UTF-16 for sqlite3_create_function16().
1593**
1594** The first argument is the [sqlite3 | database handle] that holds the
1595** SQL function or aggregate is to be added or redefined. If a single
1596** program uses more than one database handle internally, then SQL
1597** functions or aggregates must be added individually to each database
1598** handle with which they will be used.
1599**
1600** The second parameter is the name of the SQL function to be created
1601** or redefined.
1602** The length of the name is limited to 255 bytes, exclusive of the
1603** zero-terminator.  Note that the name length limit is in bytes, not
1604** characters.  Any attempt to create a function with a longer name
1605** will result in an SQLITE_ERROR error.
1606**
1607** The third parameter is the number of arguments that the SQL function or
1608** aggregate takes. If this parameter is negative, then the SQL function or
1609** aggregate may take any number of arguments.
1610**
1611** The fourth parameter, eTextRep, specifies what
1612** [SQLITE_UTF8 | text encoding] this SQL function prefers for
1613** its parameters.  Any SQL function implementation should be able to work
1614** work with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be
1615** more efficient with one encoding than another.  It is allowed to
1616** invoke sqlite_create_function() or sqlite3_create_function16() multiple
1617** times with the same function but with different values of eTextRep.
1618** When multiple implementations of the same function are available, SQLite
1619** will pick the one that involves the least amount of data conversion.
1620** If there is only a single implementation which does not care what
1621** text encoding is used, then the fourth argument should be
1622** [SQLITE_ANY].
1623**
1624** The fifth parameter is an arbitrary pointer.  The implementation
1625** of the function can gain access to this pointer using
1626** [sqlite_user_data()].
1627**
1628** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
1629** pointers to C-language functions that implement the SQL
1630** function or aggregate. A scalar SQL function requires an implementation of
1631** the xFunc callback only, NULL pointers should be passed as the xStep
1632** and xFinal parameters. An aggregate SQL function requires an implementation
1633** of xStep and xFinal and NULL should be passed for xFunc. To delete an
1634** existing SQL function or aggregate, pass NULL for all three function
1635** callback.
1636**
1637** It is permitted to register multiple implementations of the same
1638** functions with the same name but with either differing numbers of
1639** arguments or differing perferred text encodings.  SQLite will use
1640** the implementation most closely matches the way in which the
1641** SQL function is used.
1642*/
1643int sqlite3_create_function(
1644  sqlite3 *,
1645  const char *zFunctionName,
1646  int nArg,
1647  int eTextRep,
1648  void*,
1649  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
1650  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1651  void (*xFinal)(sqlite3_context*)
1652);
1653int sqlite3_create_function16(
1654  sqlite3*,
1655  const void *zFunctionName,
1656  int nArg,
1657  int eTextRep,
1658  void*,
1659  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
1660  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
1661  void (*xFinal)(sqlite3_context*)
1662);
1663
1664/*
1665** CAPI3REF: Text Encodings
1666**
1667** These constant define integer codes that represent the various
1668** text encodings supported by SQLite.
1669*/
1670#define SQLITE_UTF8           1
1671#define SQLITE_UTF16LE        2
1672#define SQLITE_UTF16BE        3
1673#define SQLITE_UTF16          4    /* Use native byte order */
1674#define SQLITE_ANY            5    /* sqlite3_create_function only */
1675#define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
1676
1677/*
1678** CAPI3REF: Obsolete Functions
1679**
1680** These functions are all now obsolete.  In order to maintain
1681** backwards compatibility with older code, we continue to support
1682** these functions.  However, new development projects should avoid
1683** the use of these functions.  To help encourage people to avoid
1684** using these functions, we are not going to tell you want they do.
1685*/
1686int sqlite3_aggregate_count(sqlite3_context*);
1687int sqlite3_expired(sqlite3_stmt*);
1688int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
1689int sqlite3_global_recover(void);
1690
1691
1692/*
1693** CAPI3REF: Obtaining SQL Function Parameter Values
1694**
1695** The C-language implementation of SQL functions and aggregates uses
1696** this set of interface routines to access the parameter values on
1697** the function or aggregate.
1698**
1699** The xFunc (for scalar functions) or xStep (for aggregates) parameters
1700** to [sqlite3_create_function()] and [sqlite3_create_function16()]
1701** define callbacks that implement the SQL functions and aggregates.
1702** The 4th parameter to these callbacks is an array of pointers to
1703** [sqlite3_value] objects.  There is one [sqlite3_value] object for
1704** each parameter to the SQL function.  These routines are used to
1705** extract values from the [sqlite3_value] objects.
1706**
1707** These routines work just like the corresponding
1708** [sqlite3_column_blob | sqlite3_column_* routines] except that
1709** these routines take a single [sqlite3_value*] pointer instead
1710** of an [sqlite3_stmt*] pointer and an integer column number.
1711**
1712** The sqlite3_value_text16() interface extracts a UTF16 string
1713** in the native byte-order of the host machine.  The
1714** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
1715** extract UTF16 strings as big-endian and little-endian respectively.
1716**
1717** The sqlite3_value_numeric_type() interface attempts to apply
1718** numeric affinity to the value.  This means that an attempt is
1719** made to convert the value to an integer or floating point.  If
1720** such a conversion is possible without loss of information (in order
1721** words if the value is original a string that looks like a number)
1722** then it is done.  Otherwise no conversion occurs.  The
1723** [SQLITE_INTEGER | datatype] after conversion is returned.
1724**
1725** Please pay particular attention to the fact that the pointer that
1726** is returned from [sqlite3_value_blob()], [sqlite3_value_text()], or
1727** [sqlite3_value_text16()] can be invalidated by a subsequent call to
1728** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite_value_text()],
1729** or [sqlite3_value_text16()].
1730*/
1731const void *sqlite3_value_blob(sqlite3_value*);
1732int sqlite3_value_bytes(sqlite3_value*);
1733int sqlite3_value_bytes16(sqlite3_value*);
1734double sqlite3_value_double(sqlite3_value*);
1735int sqlite3_value_int(sqlite3_value*);
1736sqlite_int64 sqlite3_value_int64(sqlite3_value*);
1737const unsigned char *sqlite3_value_text(sqlite3_value*);
1738const void *sqlite3_value_text16(sqlite3_value*);
1739const void *sqlite3_value_text16le(sqlite3_value*);
1740const void *sqlite3_value_text16be(sqlite3_value*);
1741int sqlite3_value_type(sqlite3_value*);
1742int sqlite3_value_numeric_type(sqlite3_value*);
1743
1744/*
1745** CAPI3REF: Obtain Aggregate Function Context
1746**
1747** The implementation of aggregate SQL functions use this routine to allocate
1748** a structure for storing their state.  The first time this routine
1749** is called for a particular aggregate, a new structure of size nBytes
1750** is allocated, zeroed, and returned.  On subsequent calls (for the
1751** same aggregate instance) the same buffer is returned.  The implementation
1752** of the aggregate can use the returned buffer to accumulate data.
1753**
1754** The buffer allocated is freed automatically by SQLite whan the aggregate
1755** query concludes.
1756**
1757** The first parameter should be a copy of the
1758** [sqlite3_context | SQL function context] that is the first
1759** parameter to the callback routine that implements the aggregate
1760** function.
1761*/
1762void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
1763
1764/*
1765** CAPI3REF: User Data For Functions
1766**
1767** The pUserData parameter to the [sqlite3_create_function()]
1768** and [sqlite3_create_function16()] routines
1769** used to register user functions is available to
1770** the implementation of the function using this call.
1771*/
1772void *sqlite3_user_data(sqlite3_context*);
1773
1774/*
1775** CAPI3REF: Function Auxiliary Data
1776**
1777** The following two functions may be used by scalar SQL functions to
1778** associate meta-data with argument values. If the same value is passed to
1779** multiple invocations of the same SQL function during query execution, under
1780** some circumstances the associated meta-data may be preserved. This may
1781** be used, for example, to add a regular-expression matching scalar
1782** function. The compiled version of the regular expression is stored as
1783** meta-data associated with the SQL value passed as the regular expression
1784** pattern.  The compiled regular expression can be reused on multiple
1785** invocations of the same function so that the original pattern string
1786** does not need to be recompiled on each invocation.
1787**
1788** The sqlite3_get_auxdata() interface returns a pointer to the meta-data
1789** associated with the Nth argument value to the current SQL function
1790** call, where N is the second parameter. If no meta-data has been set for
1791** that value, then a NULL pointer is returned.
1792**
1793** The sqlite3_set_auxdata() is used to associate meta-data with an SQL
1794** function argument. The third parameter is a pointer to the meta-data
1795** to be associated with the Nth user function argument value. The fourth
1796** parameter specifies a destructor that will be called on the meta-
1797** data pointer to release it when it is no longer required. If the
1798** destructor is NULL, it is not invoked.
1799**
1800** In practice, meta-data is preserved between function calls for
1801** expressions that are constant at compile time. This includes literal
1802** values and SQL variables.
1803*/
1804void *sqlite3_get_auxdata(sqlite3_context*, int);
1805void sqlite3_set_auxdata(sqlite3_context*, int, void*, void (*)(void*));
1806
1807
1808/*
1809** CAPI3REF: Constants Defining Special Destructor Behavior
1810**
1811** These are special value for the destructor that is passed in as the
1812** final argument to routines like [sqlite3_result_blob()].  If the destructor
1813** argument is SQLITE_STATIC, it means that the content pointer is constant
1814** and will never change.  It does not need to be destroyed.  The
1815** SQLITE_TRANSIENT value means that the content will likely change in
1816** the near future and that SQLite should make its own private copy of
1817** the content before returning.
1818**
1819** The typedef is necessary to work around problems in certain
1820** C++ compilers.  See ticket #2191.
1821*/
1822typedef void (*sqlite3_destructor_type)(void*);
1823#define SQLITE_STATIC      ((sqlite3_destructor_type)0)
1824#define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
1825
1826/*
1827** CAPI3REF: Setting The Result Of An SQL Function
1828**
1829** These routines are used by the xFunc or xFinal callbacks that
1830** implement SQL functions and aggregates.  See
1831** [sqlite3_create_function()] and [sqlite3_create_function16()]
1832** for additional information.
1833**
1834** These functions work very much like the
1835** [sqlite3_bind_blob | sqlite3_bind_*] family of functions used
1836** to bind values to host parameters in prepared statements.
1837** Refer to the
1838** [sqlite3_bind_blob | sqlite3_bind_* documentation] for
1839** additional information.
1840**
1841** The sqlite3_result_error() and sqlite3_result_error16() functions
1842** cause the implemented SQL function to throw an exception.  The
1843** parameter to sqlite3_result_error() or sqlite3_result_error16()
1844** is the text of an error message.
1845**
1846** The sqlite3_result_toobig() cause the function implementation
1847** to throw and error indicating that a string or BLOB is to long
1848** to represent.
1849*/
1850void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
1851void sqlite3_result_double(sqlite3_context*, double);
1852void sqlite3_result_error(sqlite3_context*, const char*, int);
1853void sqlite3_result_error16(sqlite3_context*, const void*, int);
1854void sqlite3_result_error_toobig(sqlite3_context*);
1855void sqlite3_result_int(sqlite3_context*, int);
1856void sqlite3_result_int64(sqlite3_context*, sqlite_int64);
1857void sqlite3_result_null(sqlite3_context*);
1858void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
1859void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
1860void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
1861void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
1862void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
1863void sqlite3_result_zeroblob(sqlite3_context*, int n);
1864
1865/*
1866** CAPI3REF: Define New Collating Sequences
1867**
1868** These functions are used to add new collation sequences to the
1869** [sqlite3*] handle specified as the first argument.
1870**
1871** The name of the new collation sequence is specified as a UTF-8 string
1872** for sqlite3_create_collation() and sqlite3_create_collation_v2()
1873** and a UTF-16 string for sqlite3_create_collation16().  In all cases
1874** the name is passed as the second function argument.
1875**
1876** The third argument must be one of the constants [SQLITE_UTF8],
1877** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied
1878** routine expects to be passed pointers to strings encoded using UTF-8,
1879** UTF-16 little-endian or UTF-16 big-endian respectively.
1880**
1881** A pointer to the user supplied routine must be passed as the fifth
1882** argument. If it is NULL, this is the same as deleting the collation
1883** sequence (so that SQLite cannot call it anymore). Each time the user
1884** supplied function is invoked, it is passed a copy of the void* passed as
1885** the fourth argument to sqlite3_create_collation() or
1886** sqlite3_create_collation16() as its first parameter.
1887**
1888** The remaining arguments to the user-supplied routine are two strings,
1889** each represented by a [length, data] pair and encoded in the encoding
1890** that was passed as the third argument when the collation sequence was
1891** registered. The user routine should return negative, zero or positive if
1892** the first string is less than, equal to, or greater than the second
1893** string. i.e. (STRING1 - STRING2).
1894**
1895** The sqlite3_create_collation_v2() works like sqlite3_create_collation()
1896** excapt that it takes an extra argument which is a destructor for
1897** the collation.  The destructor is called when the collation is
1898** destroyed and is passed a copy of the fourth parameter void* pointer
1899** of the sqlite3_create_collation_v2().  Collations are destroyed when
1900** they are overridden by later calls to the collation creation functions
1901** or when the [sqlite3*] database handle is closed using [sqlite3_close()].
1902**
1903** The sqlite3_create_collation_v2() interface is experimental and
1904** subject to change in future releases.  The other collation creation
1905** functions are stable.
1906*/
1907int sqlite3_create_collation(
1908  sqlite3*,
1909  const char *zName,
1910  int eTextRep,
1911  void*,
1912  int(*xCompare)(void*,int,const void*,int,const void*)
1913);
1914int sqlite3_create_collation_v2(
1915  sqlite3*,
1916  const char *zName,
1917  int eTextRep,
1918  void*,
1919  int(*xCompare)(void*,int,const void*,int,const void*),
1920  void(*xDestroy)(void*)
1921);
1922int sqlite3_create_collation16(
1923  sqlite3*,
1924  const char *zName,
1925  int eTextRep,
1926  void*,
1927  int(*xCompare)(void*,int,const void*,int,const void*)
1928);
1929
1930/*
1931** CAPI3REF: Collation Needed Callbacks
1932**
1933** To avoid having to register all collation sequences before a database
1934** can be used, a single callback function may be registered with the
1935** database handle to be called whenever an undefined collation sequence is
1936** required.
1937**
1938** If the function is registered using the sqlite3_collation_needed() API,
1939** then it is passed the names of undefined collation sequences as strings
1940** encoded in UTF-8. If sqlite3_collation_needed16() is used, the names
1941** are passed as UTF-16 in machine native byte order. A call to either
1942** function replaces any existing callback.
1943**
1944** When the callback is invoked, the first argument passed is a copy
1945** of the second argument to sqlite3_collation_needed() or
1946** sqlite3_collation_needed16(). The second argument is the database
1947** handle. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], or
1948** [SQLITE_UTF16LE], indicating the most desirable form of the collation
1949** sequence function required. The fourth parameter is the name of the
1950** required collation sequence.
1951**
1952** The callback function should register the desired collation using
1953** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
1954** [sqlite3_create_collation_v2()].
1955*/
1956int sqlite3_collation_needed(
1957  sqlite3*,
1958  void*,
1959  void(*)(void*,sqlite3*,int eTextRep,const char*)
1960);
1961int sqlite3_collation_needed16(
1962  sqlite3*,
1963  void*,
1964  void(*)(void*,sqlite3*,int eTextRep,const void*)
1965);
1966
1967/*
1968** Specify the key for an encrypted database.  This routine should be
1969** called right after sqlite3_open().
1970**
1971** The code to implement this API is not available in the public release
1972** of SQLite.
1973*/
1974int sqlite3_key(
1975  sqlite3 *db,                   /* Database to be rekeyed */
1976  const void *pKey, int nKey     /* The key */
1977);
1978
1979/*
1980** Change the key on an open database.  If the current database is not
1981** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
1982** database is decrypted.
1983**
1984** The code to implement this API is not available in the public release
1985** of SQLite.
1986*/
1987int sqlite3_rekey(
1988  sqlite3 *db,                   /* Database to be rekeyed */
1989  const void *pKey, int nKey     /* The new key */
1990);
1991
1992/*
1993** CAPI3REF:  Suspend Execution For A Short Time
1994**
1995** This function causes the current thread to suspend execution
1996** a number of milliseconds specified in its parameter.
1997**
1998** If the operating system does not support sleep requests with
1999** millisecond time resolution, then the time will be rounded up to
2000** the nearest second. The number of milliseconds of sleep actually
2001** requested from the operating system is returned.
2002*/
2003int sqlite3_sleep(int);
2004
2005/*
2006** CAPI3REF:  Name Of The Folder Holding Temporary Files
2007**
2008** If this global variable is made to point to a string which is
2009** the name of a folder (a.ka. directory), then all temporary files
2010** created by SQLite will be placed in that directory.  If this variable
2011** is NULL pointer, then SQLite does a search for an appropriate temporary
2012** file directory.
2013**
2014** Once [sqlite3_open()] has been called, changing this variable will
2015** invalidate the current temporary database, if any.  Generally speaking,
2016** it is not safe to invoke this routine after [sqlite3_open()] has
2017** been called.
2018*/
2019extern char *sqlite3_temp_directory;
2020
2021/*
2022** CAPI3REF:  Test To See If The Databse Is In Auto-Commit Mode
2023**
2024** Test to see whether or not the database connection is in autocommit
2025** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
2026** by default.  Autocommit is disabled by a BEGIN statement and reenabled
2027** by the next COMMIT or ROLLBACK.
2028*/
2029int sqlite3_get_autocommit(sqlite3*);
2030
2031/*
2032** CAPI3REF:  Find The Database Handle Associated With A Prepared Statement
2033**
2034** Return the [sqlite3*] database handle to which a
2035** [sqlite3_stmt | prepared statement] belongs.
2036** This is the same database handle that was
2037** the first argument to the [sqlite3_prepare_v2()] or its variants
2038** that was used to create the statement in the first place.
2039*/
2040sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
2041
2042
2043/*
2044** CAPI3REF: Commit And Rollback Notification Callbacks
2045**
2046** These routines
2047** register callback functions to be invoked whenever a transaction
2048** is committed or rolled back.  The pArg argument is passed through
2049** to the callback.  If the callback on a commit hook function
2050** returns non-zero, then the commit is converted into a rollback.
2051**
2052** If another function was previously registered, its pArg value is returned.
2053** Otherwise NULL is returned.
2054**
2055** Registering a NULL function disables the callback.
2056**
2057** For the purposes of this API, a transaction is said to have been
2058** rolled back if an explicit "ROLLBACK" statement is executed, or
2059** an error or constraint causes an implicit rollback to occur. The
2060** callback is not invoked if a transaction is automatically rolled
2061** back because the database connection is closed.
2062**
2063** These are experimental interfaces and are subject to change.
2064*/
2065void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
2066void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
2067
2068/*
2069** CAPI3REF: Data Change Notification Callbacks
2070**
2071** Register a callback function with the database connection identified by the
2072** first argument to be invoked whenever a row is updated, inserted or deleted.
2073** Any callback set by a previous call to this function for the same
2074** database connection is overridden.
2075**
2076** The second argument is a pointer to the function to invoke when a
2077** row is updated, inserted or deleted. The first argument to the callback is
2078** a copy of the third argument to sqlite3_update_hook(). The second callback
2079** argument is one of SQLITE_INSERT, SQLITE_DELETE or SQLITE_UPDATE, depending
2080** on the operation that caused the callback to be invoked. The third and
2081** fourth arguments to the callback contain pointers to the database and
2082** table name containing the affected row. The final callback parameter is
2083** the rowid of the row. In the case of an update, this is the rowid after
2084** the update takes place.
2085**
2086** The update hook is not invoked when internal system tables are
2087** modified (i.e. sqlite_master and sqlite_sequence).
2088**
2089** If another function was previously registered, its pArg value is returned.
2090** Otherwise NULL is returned.
2091*/
2092void *sqlite3_update_hook(
2093  sqlite3*,
2094  void(*)(void *,int ,char const *,char const *,sqlite_int64),
2095  void*
2096);
2097
2098/*
2099** CAPI3REF:  Enable Or Disable Shared Pager Cache
2100**
2101** This routine enables or disables the sharing of the database cache
2102** and schema data structures between connections to the same database.
2103** Sharing is enabled if the argument is true and disabled if the argument
2104** is false.
2105**
2106** Cache sharing is enabled and disabled on a thread-by-thread basis.
2107** Each call to this routine enables or disables cache sharing only for
2108** connections created in the same thread in which this routine is called.
2109** There is no mechanism for sharing cache between database connections
2110** running in different threads.
2111**
2112** Sharing must be disabled prior to shutting down a thread or else
2113** the thread will leak memory.  Call this routine with an argument of
2114** 0 to turn off sharing.  Or use the sqlite3_thread_cleanup() API.
2115**
2116** This routine must not be called when any database connections
2117** are active in the current thread.  Enabling or disabling shared
2118** cache while there are active database connections will result
2119** in memory corruption.
2120**
2121** When the shared cache is enabled, the
2122** following routines must always be called from the same thread:
2123** [sqlite3_open()], [sqlite3_prepare_v2()], [sqlite3_step()],
2124** [sqlite3_reset()], [sqlite3_finalize()], and [sqlite3_close()].
2125** This is due to the fact that the shared cache makes use of
2126** thread-specific storage so that it will be available for sharing
2127** with other connections.
2128**
2129** Virtual tables cannot be used with a shared cache.  When shared
2130** cache is enabled, the sqlite3_create_module() API used to register
2131** virtual tables will always return an error.
2132**
2133** This routine returns [SQLITE_OK] if shared cache was
2134** enabled or disabled successfully.  An [SQLITE_ERROR | error code]
2135** is returned otherwise.
2136**
2137** Shared cache is disabled by default for backward compatibility.
2138*/
2139int sqlite3_enable_shared_cache(int);
2140
2141/*
2142** CAPI3REF:  Attempt To Free Heap Memory
2143**
2144** Attempt to free N bytes of heap memory by deallocating non-essential
2145** memory allocations held by the database library (example: memory
2146** used to cache database pages to improve performance).
2147**
2148** This function is not a part of standard builds.  It is only created
2149** if SQLite is compiled with the SQLITE_ENABLE_MEMORY_MANAGEMENT macro.
2150*/
2151int sqlite3_release_memory(int);
2152
2153/*
2154** CAPI3REF:  Impose A Limit On Heap Size
2155**
2156** Place a "soft" limit on the amount of heap memory that may be allocated by
2157** SQLite within the current thread. If an internal allocation is requested
2158** that would exceed the specified limit, [sqlite3_release_memory()] is invoked
2159** one or more times to free up some space before the allocation is made.
2160**
2161** The limit is called "soft", because if [sqlite3_release_memory()] cannot free
2162** sufficient memory to prevent the limit from being exceeded, the memory is
2163** allocated anyway and the current operation proceeds.
2164**
2165** Prior to shutting down a thread sqlite3_soft_heap_limit() must be set to
2166** zero (the default) or else the thread will leak memory. Alternatively, use
2167** the [sqlite3_thread_cleanup()] API.
2168**
2169** A negative or zero value for N means that there is no soft heap limit and
2170** [sqlite3_release_memory()] will only be called when memory is exhaused.
2171** The default value for the soft heap limit is zero.
2172**
2173** SQLite makes a best effort to honor the soft heap limit.  But if it
2174** is unable to reduce memory usage below the soft limit, execution will
2175** continue without error or notification.  This is why the limit is
2176** called a "soft" limit.  It is advisory only.
2177**
2178** This function is only available if the library was compiled with the
2179** SQLITE_ENABLE_MEMORY_MANAGEMENT option set.
2180** memory-management has been enabled.
2181*/
2182void sqlite3_soft_heap_limit(int);
2183
2184/*
2185** CAPI3REF:  Clean Up Thread Local Storage
2186**
2187** This routine makes sure that all thread-local storage has been
2188** deallocated for the current thread.
2189**
2190** This routine is not technically necessary.  All thread-local storage
2191** will be automatically deallocated once memory-management and
2192** shared-cache are disabled and the soft heap limit has been set
2193** to zero.  This routine is provided as a convenience for users who
2194** want to make absolutely sure they have not forgotten something
2195** prior to killing off a thread.
2196*/
2197void sqlite3_thread_cleanup(void);
2198
2199/*
2200** CAPI3REF:  Extract Metadata About A Column Of A Table
2201**
2202** This routine
2203** returns meta-data about a specific column of a specific database
2204** table accessible using the connection handle passed as the first function
2205** argument.
2206**
2207** The column is identified by the second, third and fourth parameters to
2208** this function. The second parameter is either the name of the database
2209** (i.e. "main", "temp" or an attached database) containing the specified
2210** table or NULL. If it is NULL, then all attached databases are searched
2211** for the table using the same algorithm as the database engine uses to
2212** resolve unqualified table references.
2213**
2214** The third and fourth parameters to this function are the table and column
2215** name of the desired column, respectively. Neither of these parameters
2216** may be NULL.
2217**
2218** Meta information is returned by writing to the memory locations passed as
2219** the 5th and subsequent parameters to this function. Any of these
2220** arguments may be NULL, in which case the corresponding element of meta
2221** information is ommitted.
2222**
2223** <pre>
2224** Parameter     Output Type      Description
2225** -----------------------------------
2226**
2227**   5th         const char*      Data type
2228**   6th         const char*      Name of the default collation sequence
2229**   7th         int              True if the column has a NOT NULL constraint
2230**   8th         int              True if the column is part of the PRIMARY KEY
2231**   9th         int              True if the column is AUTOINCREMENT
2232** </pre>
2233**
2234**
2235** The memory pointed to by the character pointers returned for the
2236** declaration type and collation sequence is valid only until the next
2237** call to any sqlite API function.
2238**
2239** If the specified table is actually a view, then an error is returned.
2240**
2241** If the specified column is "rowid", "oid" or "_rowid_" and an
2242** INTEGER PRIMARY KEY column has been explicitly declared, then the output
2243** parameters are set for the explicitly declared column. If there is no
2244** explicitly declared IPK column, then the output parameters are set as
2245** follows:
2246**
2247** <pre>
2248**     data type: "INTEGER"
2249**     collation sequence: "BINARY"
2250**     not null: 0
2251**     primary key: 1
2252**     auto increment: 0
2253** </pre>
2254**
2255** This function may load one or more schemas from database files. If an
2256** error occurs during this process, or if the requested table or column
2257** cannot be found, an SQLITE error code is returned and an error message
2258** left in the database handle (to be retrieved using sqlite3_errmsg()).
2259**
2260** This API is only available if the library was compiled with the
2261** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
2262*/
2263int sqlite3_table_column_metadata(
2264  sqlite3 *db,                /* Connection handle */
2265  const char *zDbName,        /* Database name or NULL */
2266  const char *zTableName,     /* Table name */
2267  const char *zColumnName,    /* Column name */
2268  char const **pzDataType,    /* OUTPUT: Declared data type */
2269  char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
2270  int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
2271  int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
2272  int *pAutoinc               /* OUTPUT: True if colums is auto-increment */
2273);
2274
2275/*
2276** CAPI3REF: Load An Extension
2277**
2278** Attempt to load an SQLite extension library contained in the file
2279** zFile.  The entry point is zProc.  zProc may be 0 in which case the
2280** name of the entry point defaults to "sqlite3_extension_init".
2281**
2282** Return [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
2283**
2284** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
2285** error message text.  The calling function should free this memory
2286** by calling [sqlite3_free()].
2287**
2288** Extension loading must be enabled using [sqlite3_enable_load_extension()]
2289** prior to calling this API or an error will be returned.
2290*/
2291int sqlite3_load_extension(
2292  sqlite3 *db,          /* Load the extension into this database connection */
2293  const char *zFile,    /* Name of the shared library containing extension */
2294  const char *zProc,    /* Entry point.  Derived from zFile if 0 */
2295  char **pzErrMsg       /* Put error message here if not 0 */
2296);
2297
2298/*
2299** CAPI3REF:  Enable Or Disable Extension Loading
2300**
2301** So as not to open security holes in older applications that are
2302** unprepared to deal with extension loading, and as a means of disabling
2303** extension loading while evaluating user-entered SQL, the following
2304** API is provided to turn the [sqlite3_load_extension()] mechanism on and
2305** off.  It is off by default.  See ticket #1863.
2306**
2307** Call this routine with onoff==1 to turn extension loading on
2308** and call it with onoff==0 to turn it back off again.
2309*/
2310int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
2311
2312/*
2313** CAPI3REF: Make Arrangements To Automatically Load An Extension
2314**
2315** Register an extension entry point that is automatically invoked
2316** whenever a new database connection is opened using
2317** [sqlite3_open()] or [sqlite3_open16()].
2318**
2319** This API can be invoked at program startup in order to register
2320** one or more statically linked extensions that will be available
2321** to all new database connections.
2322**
2323** Duplicate extensions are detected so calling this routine multiple
2324** times with the same extension is harmless.
2325**
2326** This routine stores a pointer to the extension in an array
2327** that is obtained from malloc().  If you run a memory leak
2328** checker on your program and it reports a leak because of this
2329** array, then invoke [sqlite3_automatic_extension_reset()] prior
2330** to shutdown to free the memory.
2331**
2332** Automatic extensions apply across all threads.
2333**
2334** This interface is experimental and is subject to change or
2335** removal in future releases of SQLite.
2336*/
2337int sqlite3_auto_extension(void *xEntryPoint);
2338
2339
2340/*
2341** CAPI3REF: Reset Automatic Extension Loading
2342**
2343** Disable all previously registered automatic extensions.  This
2344** routine undoes the effect of all prior [sqlite3_automatic_extension()]
2345** calls.
2346**
2347** This call disabled automatic extensions in all threads.
2348**
2349** This interface is experimental and is subject to change or
2350** removal in future releases of SQLite.
2351*/
2352void sqlite3_reset_auto_extension(void);
2353
2354
2355/*
2356****** EXPERIMENTAL - subject to change without notice **************
2357**
2358** The interface to the virtual-table mechanism is currently considered
2359** to be experimental.  The interface might change in incompatible ways.
2360** If this is a problem for you, do not use the interface at this time.
2361**
2362** When the virtual-table mechanism stablizes, we will declare the
2363** interface fixed, support it indefinitely, and remove this comment.
2364*/
2365
2366/*
2367** Structures used by the virtual table interface
2368*/
2369typedef struct sqlite3_vtab sqlite3_vtab;
2370typedef struct sqlite3_index_info sqlite3_index_info;
2371typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
2372typedef struct sqlite3_module sqlite3_module;
2373
2374/*
2375** A module is a class of virtual tables.  Each module is defined
2376** by an instance of the following structure.  This structure consists
2377** mostly of methods for the module.
2378*/
2379struct sqlite3_module {
2380  int iVersion;
2381  int (*xCreate)(sqlite3*, void *pAux,
2382               int argc, const char *const*argv,
2383               sqlite3_vtab **ppVTab, char**);
2384  int (*xConnect)(sqlite3*, void *pAux,
2385               int argc, const char *const*argv,
2386               sqlite3_vtab **ppVTab, char**);
2387  int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
2388  int (*xDisconnect)(sqlite3_vtab *pVTab);
2389  int (*xDestroy)(sqlite3_vtab *pVTab);
2390  int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
2391  int (*xClose)(sqlite3_vtab_cursor*);
2392  int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
2393                int argc, sqlite3_value **argv);
2394  int (*xNext)(sqlite3_vtab_cursor*);
2395  int (*xEof)(sqlite3_vtab_cursor*);
2396  int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
2397  int (*xRowid)(sqlite3_vtab_cursor*, sqlite_int64 *pRowid);
2398  int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite_int64 *);
2399  int (*xBegin)(sqlite3_vtab *pVTab);
2400  int (*xSync)(sqlite3_vtab *pVTab);
2401  int (*xCommit)(sqlite3_vtab *pVTab);
2402  int (*xRollback)(sqlite3_vtab *pVTab);
2403  int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
2404                       void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
2405                       void **ppArg);
2406};
2407
2408/*
2409** The sqlite3_index_info structure and its substructures is used to
2410** pass information into and receive the reply from the xBestIndex
2411** method of an sqlite3_module.  The fields under **Inputs** are the
2412** inputs to xBestIndex and are read-only.  xBestIndex inserts its
2413** results into the **Outputs** fields.
2414**
2415** The aConstraint[] array records WHERE clause constraints of the
2416** form:
2417**
2418**         column OP expr
2419**
2420** Where OP is =, <, <=, >, or >=.  The particular operator is stored
2421** in aConstraint[].op.  The index of the column is stored in
2422** aConstraint[].iColumn.  aConstraint[].usable is TRUE if the
2423** expr on the right-hand side can be evaluated (and thus the constraint
2424** is usable) and false if it cannot.
2425**
2426** The optimizer automatically inverts terms of the form "expr OP column"
2427** and makes other simplificatinos to the WHERE clause in an attempt to
2428** get as many WHERE clause terms into the form shown above as possible.
2429** The aConstraint[] array only reports WHERE clause terms in the correct
2430** form that refer to the particular virtual table being queried.
2431**
2432** Information about the ORDER BY clause is stored in aOrderBy[].
2433** Each term of aOrderBy records a column of the ORDER BY clause.
2434**
2435** The xBestIndex method must fill aConstraintUsage[] with information
2436** about what parameters to pass to xFilter.  If argvIndex>0 then
2437** the right-hand side of the corresponding aConstraint[] is evaluated
2438** and becomes the argvIndex-th entry in argv.  If aConstraintUsage[].omit
2439** is true, then the constraint is assumed to be fully handled by the
2440** virtual table and is not checked again by SQLite.
2441**
2442** The idxNum and idxPtr values are recorded and passed into xFilter.
2443** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true.
2444**
2445** The orderByConsumed means that output from xFilter will occur in
2446** the correct order to satisfy the ORDER BY clause so that no separate
2447** sorting step is required.
2448**
2449** The estimatedCost value is an estimate of the cost of doing the
2450** particular lookup.  A full scan of a table with N entries should have
2451** a cost of N.  A binary search of a table of N entries should have a
2452** cost of approximately log(N).
2453*/
2454struct sqlite3_index_info {
2455  /* Inputs */
2456  const int nConstraint;     /* Number of entries in aConstraint */
2457  const struct sqlite3_index_constraint {
2458     int iColumn;              /* Column on left-hand side of constraint */
2459     unsigned char op;         /* Constraint operator */
2460     unsigned char usable;     /* True if this constraint is usable */
2461     int iTermOffset;          /* Used internally - xBestIndex should ignore */
2462  } *const aConstraint;      /* Table of WHERE clause constraints */
2463  const int nOrderBy;        /* Number of terms in the ORDER BY clause */
2464  const struct sqlite3_index_orderby {
2465     int iColumn;              /* Column number */
2466     unsigned char desc;       /* True for DESC.  False for ASC. */
2467  } *const aOrderBy;         /* The ORDER BY clause */
2468
2469  /* Outputs */
2470  struct sqlite3_index_constraint_usage {
2471    int argvIndex;           /* if >0, constraint is part of argv to xFilter */
2472    unsigned char omit;      /* Do not code a test for this constraint */
2473  } *const aConstraintUsage;
2474  int idxNum;                /* Number used to identify the index */
2475  char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
2476  int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
2477  int orderByConsumed;       /* True if output is already ordered */
2478  double estimatedCost;      /* Estimated cost of using this index */
2479};
2480#define SQLITE_INDEX_CONSTRAINT_EQ    2
2481#define SQLITE_INDEX_CONSTRAINT_GT    4
2482#define SQLITE_INDEX_CONSTRAINT_LE    8
2483#define SQLITE_INDEX_CONSTRAINT_LT    16
2484#define SQLITE_INDEX_CONSTRAINT_GE    32
2485#define SQLITE_INDEX_CONSTRAINT_MATCH 64
2486
2487/*
2488** This routine is used to register a new module name with an SQLite
2489** connection.  Module names must be registered before creating new
2490** virtual tables on the module, or before using preexisting virtual
2491** tables of the module.
2492*/
2493int sqlite3_create_module(
2494  sqlite3 *db,               /* SQLite connection to register module with */
2495  const char *zName,         /* Name of the module */
2496  const sqlite3_module *,    /* Methods for the module */
2497  void *                     /* Client data for xCreate/xConnect */
2498);
2499
2500/*
2501** This routine is identical to the sqlite3_create_module() method above,
2502** except that it allows a destructor function to be specified. It is
2503** even more experimental than the rest of the virtual tables API.
2504*/
2505int sqlite3_create_module_v2(
2506  sqlite3 *db,               /* SQLite connection to register module with */
2507  const char *zName,         /* Name of the module */
2508  const sqlite3_module *,    /* Methods for the module */
2509  void *,                    /* Client data for xCreate/xConnect */
2510  void(*xDestroy)(void*)     /* Module destructor function */
2511);
2512
2513/*
2514** Every module implementation uses a subclass of the following structure
2515** to describe a particular instance of the module.  Each subclass will
2516** be taylored to the specific needs of the module implementation.   The
2517** purpose of this superclass is to define certain fields that are common
2518** to all module implementations.
2519**
2520** Virtual tables methods can set an error message by assigning a
2521** string obtained from sqlite3_mprintf() to zErrMsg.  The method should
2522** take care that any prior string is freed by a call to sqlite3_free()
2523** prior to assigning a new string to zErrMsg.  After the error message
2524** is delivered up to the client application, the string will be automatically
2525** freed by sqlite3_free() and the zErrMsg field will be zeroed.  Note
2526** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field
2527** since virtual tables are commonly implemented in loadable extensions which
2528** do not have access to sqlite3MPrintf() or sqlite3Free().
2529*/
2530struct sqlite3_vtab {
2531  const sqlite3_module *pModule;  /* The module for this virtual table */
2532  int nRef;                       /* Used internally */
2533  char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
2534  /* Virtual table implementations will typically add additional fields */
2535};
2536
2537/* Every module implementation uses a subclass of the following structure
2538** to describe cursors that point into the virtual table and are used
2539** to loop through the virtual table.  Cursors are created using the
2540** xOpen method of the module.  Each module implementation will define
2541** the content of a cursor structure to suit its own needs.
2542**
2543** This superclass exists in order to define fields of the cursor that
2544** are common to all implementations.
2545*/
2546struct sqlite3_vtab_cursor {
2547  sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
2548  /* Virtual table implementations will typically add additional fields */
2549};
2550
2551/*
2552** The xCreate and xConnect methods of a module use the following API
2553** to declare the format (the names and datatypes of the columns) of
2554** the virtual tables they implement.
2555*/
2556int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);
2557
2558/*
2559** Virtual tables can provide alternative implementations of functions
2560** using the xFindFunction method.  But global versions of those functions
2561** must exist in order to be overloaded.
2562**
2563** This API makes sure a global version of a function with a particular
2564** name and number of parameters exists.  If no such function exists
2565** before this API is called, a new function is created.  The implementation
2566** of the new function always causes an exception to be thrown.  So
2567** the new function is not good for anything by itself.  Its only
2568** purpose is to be a place-holder function that can be overloaded
2569** by virtual tables.
2570**
2571** This API should be considered part of the virtual table interface,
2572** which is experimental and subject to change.
2573*/
2574int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
2575
2576/*
2577** The interface to the virtual-table mechanism defined above (back up
2578** to a comment remarkably similar to this one) is currently considered
2579** to be experimental.  The interface might change in incompatible ways.
2580** If this is a problem for you, do not use the interface at this time.
2581**
2582** When the virtual-table mechanism stablizes, we will declare the
2583** interface fixed, support it indefinitely, and remove this comment.
2584**
2585****** EXPERIMENTAL - subject to change without notice **************
2586*/
2587
2588/*
2589** CAPI3REF: A Handle To An Open BLOB
2590**
2591** An instance of the following opaque structure is used to
2592** represent an blob-handle.  A blob-handle is created by
2593** [sqlite3_blob_open()] and destroyed by [sqlite3_blob_close()].
2594** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
2595** can be used to read or write small subsections of the blob.
2596** The [sqltie3_blob_size()] interface returns the size of the
2597** blob in bytes.
2598*/
2599typedef struct sqlite3_blob sqlite3_blob;
2600
2601/*
2602** CAPI3REF: Open A BLOB For Incremental I/O
2603**
2604** Open a handle to the blob located in row iRow,, column zColumn,
2605** table zTable in database zDb. i.e. the same blob that would
2606** be selected by:
2607**
2608** <pre>
2609**     SELECT zColumn FROM zDb.zTable WHERE rowid = iRow;
2610** </pre>
2611**
2612** If the flags parameter is non-zero, the blob is opened for
2613** read and write access. If it is zero, the blob is opened for read
2614** access.
2615**
2616** On success, [SQLITE_OK] is returned and the new
2617** [sqlite3_blob | blob handle] is written to *ppBlob.
2618** Otherwise an error code is returned and
2619** any value written to *ppBlob should not be used by the caller.
2620** This function sets the database-handle error code and message
2621** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
2622*/
2623int sqlite3_blob_open(
2624  sqlite3*,
2625  const char *zDb,
2626  const char *zTable,
2627  const char *zColumn,
2628  sqlite_int64 iRow,
2629  int flags,
2630  sqlite3_blob **ppBlob
2631);
2632
2633/*
2634** CAPI3REF:  Close A BLOB Handle
2635**
2636** Close an open [sqlite3_blob | blob handle].
2637*/
2638int sqlite3_blob_close(sqlite3_blob *);
2639
2640/*
2641** CAPI3REF:  Return The Size Of An Open BLOB
2642**
2643** Return the size in bytes of the blob accessible via the open
2644** [sqlite3_blob | blob-handle] passed as an argument.
2645*/
2646int sqlite3_blob_bytes(sqlite3_blob *);
2647
2648/*
2649** CAPI3REF:  Read Data From A BLOB Incrementally
2650**
2651** This function is used to read data from an open
2652** [sqlite3_blob | blob-handle] into a caller supplied buffer.
2653** n bytes of data are copied into buffer
2654** z from the open blob, starting at offset iOffset.
2655**
2656** On success, SQLITE_OK is returned. Otherwise, an
2657** [SQLITE_ERROR | SQLite error code] or an
2658** [SQLITE_IOERR_READ | extended error code] is returned.
2659*/
2660int sqlite3_blob_read(sqlite3_blob *, void *z, int n, int iOffset);
2661
2662/*
2663** CAPI3REF:  Write Data Into A BLOB Incrementally
2664**
2665** This function is used to write data into an open
2666** [sqlite3_blob | blob-handle] from a user supplied buffer.
2667** n bytes of data are copied from the buffer
2668** pointed to by z into the open blob, starting at offset iOffset.
2669**
2670** If the [sqlite3_blob | blob-handle] passed as the first argument
2671** was not opened for writing (the flags parameter to [sqlite3_blob_open()]
2672*** was zero), this function returns [SQLITE_READONLY].
2673**
2674** This function may only modify the contents of the blob, it is
2675** not possible to increase the size of a blob using this API. If
2676** offset iOffset is less than n bytes from the end of the blob,
2677** [SQLITE_ERROR] is returned and no data is written.
2678**
2679** On success, SQLITE_OK is returned. Otherwise, an
2680** [SQLITE_ERROR | SQLite error code] or an
2681** [SQLITE_IOERR_READ | extended error code] is returned.
2682*/
2683int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
2684
2685/*
2686** Undo the hack that converts floating point types to integer for
2687** builds on processors without floating point support.
2688*/
2689#ifdef SQLITE_OMIT_FLOATING_POINT
2690# undef double
2691#endif
2692
2693#ifdef __cplusplus
2694}  /* End of the 'extern "C"' block */
2695#endif
2696#endif
2697