# sqlite3.h

    00001 /*
    00002 ** 2001 September 15
    00003 **
    00004 ** The author disclaims copyright to this source code.  In place of
    00005 ** a legal notice, here is a blessing:
    00006 **
    00007 **    May you do good and not evil.
    00008 **    May you find forgiveness for yourself and forgive others.
    00009 **    May you share freely, never taking more than you give.
    00010 **
    00011 *************************************************************************
    00012 ** This header file defines the interface that the SQLite library
    00013 ** presents to client programs.  If a C-function, structure, datatype,
    00014 ** or constant definition does not appear in this file, then it is
    00015 ** not a published API of SQLite, is subject to change without
    00016 ** notice, and should not be referenced by programs that use SQLite.
    00017 **
    00018 ** Some of the definitions that are in this file are marked as
    00019 ** "experimental".  Experimental interfaces are normally new
    00020 ** features recently added to SQLite.  We do not anticipate changes
    00021 ** to experimental interfaces but reserve to make minor changes if
    00022 ** experience from use "in the wild" suggest such changes are prudent.
    00023 **
    00024 ** The official C-language API documentation for SQLite is derived
    00025 ** from comments in this file.  This file is the authoritative source
    00026 ** on how SQLite interfaces are suppose to operate.
    00027 **
    00028 ** The name of this file under configuration management is "sqlite.h.in".
    00029 ** The makefile makes some minor changes to this file (such as inserting
    00030 ** the version number) and changes its name to "sqlite3.h" as
    00031 ** part of the build process.
    00032 **
    00033 ** @(#) $Id: sqlite.h.in,v 1.256 2007/09/03 20:32:45 drh Exp $
    00034 */
    00035 #ifndef _SQLITE3_H_
    00036 #define _SQLITE3_H_
    00037 #include <stdarg.h>     /* Needed for the definition of va_list */
    00038
    00039 /*
    00040 ** Make sure we can call this stuff from C++.
    00041 */
    00042 #ifdef __cplusplus
    00043 extern "C" {
    00044 #endif
    00045
    00046
    00047 /*
    00048 ** Add the ability to override 'extern'
    00049 */
    00050 #ifndef SQLITE_EXTERN
    00051 # define SQLITE_EXTERN extern
    00052 #endif
    00053
    00054 /*
    00055 ** Make sure these symbols where not defined by some previous header
    00056 ** file.
    00057 */
    00058 #ifdef SQLITE_VERSION
    00059 # undef SQLITE_VERSION
    00060 #endif
    00061 #ifdef SQLITE_VERSION_NUMBER
    00062 # undef SQLITE_VERSION_NUMBER
    00063 #endif
    00064
    00065 /*
    00066 ** CAPI3REF: Compile-Time Library Version Numbers
    00067 **
    00068 ** The version of the SQLite library is contained in the sqlite3.h
    00069 ** header file in a #define named SQLITE_VERSION.  The SQLITE_VERSION
    00070 ** macro resolves to a string constant.
    00071 **
    00072 ** The format of the version string is "X.Y.Z", where
    00073 ** X is the major version number, Y is the minor version number and Z
    00074 ** is the release number.  The X.Y.Z might be followed by "alpha" or "beta".
    00075 ** For example "3.1.1beta".
    00076 **
    00077 ** The X value is always 3 in SQLite.  The X value only changes when
    00078 ** backwards compatibility is broken and we intend to never break
    00079 ** backwards compatibility.  The Y value only changes when
    00080 ** there are major feature enhancements that are forwards compatible
    00081 ** but not backwards compatible.  The Z value is incremented with
    00082 ** each release but resets back to 0 when Y is incremented.
    00083 **
    00084 ** The SQLITE_VERSION_NUMBER is an integer with the value
    00085 ** (X*1000000 + Y*1000 + Z). For example, for version "3.1.1beta",
    00086 ** SQLITE_VERSION_NUMBER is set to 3001001. To detect if they are using
    00087 ** version 3.1.1 or greater at compile time, programs may use the test
    00088 ** (SQLITE_VERSION_NUMBER>=3001001).
    00089 **
    00090 ** See also: [sqlite3_libversion()] and [sqlite3_libversion_number()].
    00091 */
    00092 #define SQLITE_VERSION         "3.5.0"
    00093 #define SQLITE_VERSION_NUMBER 3005000
    00094
    00095 /*
    00096 ** CAPI3REF: Run-Time Library Version Numbers
    00097 **
    00098 ** These routines return values equivalent to the header constants
    00099 ** [SQLITE_VERSION] and [SQLITE_VERSION_NUMBER].  The values returned
    00100 ** by this routines should only be different from the header values
    00101 ** if you compile your program using an sqlite3.h header from a
    00102 ** different version of SQLite that the version of the library you
    00103 ** link against.
    00104 **
    00105 ** The sqlite3_version[] string constant contains the text of the
    00106 ** [SQLITE_VERSION] string.  The sqlite3_libversion() function returns
    00107 ** a poiner to the sqlite3_version[] string constant.  The function
    00108 ** is provided for DLL users who can only access functions and not
    00109 ** constants within the DLL.
    00110 */
    00111 SQLITE_EXTERN const char sqlite3_version[];
    00112 const char *sqlite3_libversion(void);
    00113 int sqlite3_libversion_number(void);
    00114
    00115 /*
    00116 ** CAPI3REF: Test To See If The Library Is Threadsafe
    00117 **
    00118 ** This routine returns TRUE (nonzero) if SQLite was compiled with
    00119 ** all of its mutexes enabled and is thus threadsafe.  It returns
    00120 ** zero if the particular build is for single-threaded operation
    00121 ** only.
    00122 **
    00123 ** Really all this routine does is return true if SQLite was compiled
    00124 ** with the -DSQLITE_THREADSAFE=1 option and false if
    00125 ** compiled with -DSQLITE_THREADSAFE=0.  If SQLite uses an
    00126 ** application-defined mutex subsystem, malloc subsystem, collating
    00127 ** sequence, VFS, SQL function, progress callback, commit hook,
    00128 ** extension, or other accessories and these add-ons are not
    00129 ** threadsafe, then clearly the combination will not be threadsafe
    00130 ** either.  Hence, this routine never reports that the library
    00131 ** is guaranteed to be threadsafe, only when it is guaranteed not
    00132 ** to be.
    00133 **
    00134 ** This is an experimental API and may go away or change in future
    00135 ** releases.
    00136 */
    00137 int sqlite3_threadsafe(void);
    00138
    00139 /*
    00140 ** CAPI3REF: Database Connection Handle
    00141 **
    00142 ** Each open SQLite database is represented by pointer to an instance of the
    00143 ** opaque structure named "sqlite3".  It is useful to think of an sqlite3
    00144 ** pointer as an object.  The [sqlite3_open()], [sqlite3_open16()], and
    00145 ** [sqlite3_open_v2()] interfaces are its constructors
    00146 ** and [sqlite3_close()] is its destructor.  There are many other interfaces
    00147 ** (such as [sqlite3_prepare_v2()], [sqlite3_create_function()], and
    00148 ** [sqlite3_busy_timeout()] to name but three) that are methods on this
    00149 ** object.
    00150 */
    00151 typedef struct sqlite3 sqlite3;
    00152
    00153
    00154 /*
    00155 ** CAPI3REF: 64-Bit Integer Types
    00156 **
    00157 ** Some compilers do not support the "long long" datatype.  So we have
    00158 ** to do compiler-specific typedefs for 64-bit signed and unsigned integers.
    00159 **
    00160 ** Many SQLite interface functions require a 64-bit integer arguments.
    00161 ** Those interfaces are declared using this typedef.
    00162 */
    00163 #ifdef SQLITE_INT64_TYPE
    00164   typedef SQLITE_INT64_TYPE sqlite_int64;
    00165   typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
    00166 #elif defined(_MSC_VER) || defined(__BORLANDC__)
    00167   typedef __int64 sqlite_int64;
    00168   typedef unsigned __int64 sqlite_uint64;
    00169 #else
    00170   typedef long long int sqlite_int64;
    00171   typedef unsigned long long int sqlite_uint64;
    00172 #endif
    00173 typedef sqlite_int64 sqlite3_int64;
    00174 typedef sqlite_uint64 sqlite3_uint64;
    00175
    00176 /*
    00177 ** If compiling for a processor that lacks floating point support,
    00178 ** substitute integer for floating-point
    00179 */
    00180 #ifdef SQLITE_OMIT_FLOATING_POINT
    00181 # define double sqlite3_int64
    00182 #endif
    00183
    00184 /*
    00185 ** CAPI3REF: Closing A Database Connection
    00186 **
    00187 ** Call this function with a pointer to a structure that was previously
    00188 ** returned from [sqlite3_open()], [sqlite3_open16()], or
    00189 ** [sqlite3_open_v2()] and the corresponding database will by
    00190 ** closed.
    00191 **
    00192 ** All SQL statements prepared using [sqlite3_prepare_v2()] or
    00193 ** [sqlite3_prepare16_v2()] must be destroyed using [sqlite3_finalize()]
    00194 ** before this routine is called. Otherwise, SQLITE_BUSY is returned and the
    00195 ** database connection remains open.
    00196 **
    00197 ** Passing this routine a database connection that has already been
    00198 ** closed results in undefined behavior.  If other interfaces that
    00199 ** reference the same database connection are pending (either in the
    00200 ** same thread or in different threads) when this routine is called,
    00201 ** then the behavior is undefined and is almost certainly undesirable.
    00202 */
    00203 int sqlite3_close(sqlite3 *);
    00204
    00205 /*
    00206 ** The type for a callback function.
    00207 ** This is legacy and deprecated.  It is included for historical
    00208 ** compatibility and is not documented.
    00209 */
    00210 typedef int (*sqlite3_callback)(void*,int,char**, char**);
    00211
    00212 /*
    00213 ** CAPI3REF: One-Step Query Execution Interface
    00214 **
    00215 ** This interface is used to do a one-time evaluatation of zero
    00216 ** or more SQL statements.  UTF-8 text of the SQL statements to
    00217 ** be evaluted is passed in as the second parameter.  The statements
    00218 ** are prepared one by one using [sqlite3_prepare()], evaluated
    00219 ** using [sqlite3_step()], then destroyed using [sqlite3_finalize()].
    00220 **
    00221 ** If one or more of the SQL statements are queries, then
    00222 ** the callback function specified by the 3rd parameter is
    00223 ** invoked once for each row of the query result.  This callback
    00224 ** should normally return 0.  If the callback returns a non-zero
    00225 ** value then the query is aborted, all subsequent SQL statements
    00226 ** are skipped and the sqlite3_exec() function returns the [SQLITE_ABORT].
    00227 **
    00228 ** The 4th parameter to this interface is an arbitrary pointer that is
    00229 ** passed through to the callback function as its first parameter.
    00230 **
    00231 ** The 2nd parameter to the callback function is the number of
    00232 ** columns in the query result.  The 3rd parameter to the callback
    00233 ** is an array of strings holding the values for each column
    00234 ** as extracted using [sqlite3_column_text()].
    00235 ** The 4th parameter to the callback is an array of strings
    00236 ** obtained using [sqlite3_column_name()] and holding
    00237 ** the names of each column.
    00238 **
    00239 ** The callback function may be NULL, even for queries.  A NULL
    00240 ** callback is not an error.  It just means that no callback
    00241 ** will be invoked.
    00242 **
    00243 ** If an error occurs while parsing or evaluating the SQL (but
    00244 ** not while executing the callback) then an appropriate error
    00245 ** message is written into memory obtained from [sqlite3_malloc()] and
    00246 ** *errmsg is made to point to that message.  The calling function
    00247 ** is responsible for freeing the memory using [sqlite3_free()].
    00248 ** If errmsg==NULL, then no error message is ever written.
    00249 **
    00250 ** The return value is is SQLITE_OK if there are no errors and
    00251 ** some other [SQLITE_OK | return code] if there is an error.
    00252 ** The particular return value depends on the type of error.
    00253 **
    00254 */
    00255 int sqlite3_exec(
    00256   sqlite3*,                                  /* An open database */
    00257   const char *sql,                           /* SQL to be evaluted */
    00258   int (*callback)(void*,int,char**,char**),  /* Callback function */
    00259   void *,                                    /* 1st argument to callback */
    00260   char **errmsg                              /* Error msg written here */
    00261 );
    00262
    00263 /*
    00264 ** CAPI3REF: Result Codes
    00265 ** KEYWORDS: SQLITE_OK
    00266 **
    00267 ** Many SQLite functions return an integer result code from the set shown
    00268 ** above in order to indicates success or failure.
    00269 **
    00270 ** The result codes above are the only ones returned by SQLite in its
    00271 ** default configuration.  However, the [sqlite3_extended_result_codes()]
    00272 ** API can be used to set a database connectoin to return more detailed
    00273 ** result codes.
    00274 **
    00275 ** See also: [SQLITE_IOERR_READ | extended result codes]
    00276 **
    00277 */
    00278 #define SQLITE_OK           0   /* Successful result */
    00279 /* beginning-of-error-codes */
    00280 #define SQLITE_ERROR        1   /* SQL error or missing database */
    00281 #define SQLITE_INTERNAL     2   /* NOT USED. Internal logic error in SQLite */
    00282 #define SQLITE_PERM         3   /* Access permission denied */
    00283 #define SQLITE_ABORT        4   /* Callback routine requested an abort */
    00284 #define SQLITE_BUSY         5   /* The database file is locked */
    00285 #define SQLITE_LOCKED       6   /* A table in the database is locked */
    00286 #define SQLITE_NOMEM        7   /* A malloc() failed */
    00287 #define SQLITE_READONLY     8   /* Attempt to write a readonly database */
    00288 #define SQLITE_INTERRUPT    9   /* Operation terminated by sqlite3_interrupt()*/
    00289 #define SQLITE_IOERR       10   /* Some kind of disk I/O error occurred */
    00290 #define SQLITE_CORRUPT     11   /* The database disk image is malformed */
    00291 #define SQLITE_NOTFOUND    12   /* NOT USED. Table or record not found */
    00292 #define SQLITE_FULL        13   /* Insertion failed because database is full */
    00293 #define SQLITE_CANTOPEN    14   /* Unable to open the database file */
    00294 #define SQLITE_PROTOCOL    15   /* NOT USED. Database lock protocol error */
    00295 #define SQLITE_EMPTY       16   /* Database is empty */
    00296 #define SQLITE_SCHEMA      17   /* The database schema changed */
    00297 #define SQLITE_TOOBIG      18   /* String or BLOB exceeds size limit */
    00298 #define SQLITE_CONSTRAINT  19   /* Abort due to contraint violation */
    00299 #define SQLITE_MISMATCH    20   /* Data type mismatch */
    00300 #define SQLITE_MISUSE      21   /* Library used incorrectly */
    00301 #define SQLITE_NOLFS       22   /* Uses OS features not supported on host */
    00302 #define SQLITE_AUTH        23   /* Authorization denied */
    00303 #define SQLITE_FORMAT      24   /* Auxiliary database format error */
    00304 #define SQLITE_RANGE       25   /* 2nd parameter to sqlite3_bind out of range */
    00305 #define SQLITE_NOTADB      26   /* File opened that is not a database file */
    00306 #define SQLITE_ROW         100  /* sqlite3_step() has another row ready */
    00307 #define SQLITE_DONE        101  /* sqlite3_step() has finished executing */
    00308 /* end-of-error-codes */
    00309
    00310 /*
    00311 ** CAPI3REF: Extended Result Codes
    00312 **
    00313 ** In its default configuration, SQLite API routines return one of 26 integer
    00314 ** result codes described at result-codes.  However, experience has shown that
    00315 ** many of these result codes are too course-grained.  They do not provide as
    00316 ** much information about problems as users might like.  In an effort to
    00317 ** address this, newer versions of SQLite (version 3.3.8 and later) include
    00318 ** support for additional result codes that provide more detailed information
    00319 ** about errors.  The extended result codes are enabled (or disabled) for
    00320 ** each database
    00321 ** connection using the [sqlite3_extended_result_codes()] API.
    00322 **
    00323 ** Some of the available extended result codes are listed above.
    00324 ** We expect the number of extended result codes will be expand
    00325 ** over time.  Software that uses extended result codes should expect
    00326 ** to see new result codes in future releases of SQLite.
    00327 **
    00328 ** The symbolic name for an extended result code always contains a related
    00329 ** primary result code as a prefix.  Primary result codes contain a single
    00330 ** "_" character.  Extended result codes contain two or more "_" characters.
    00331 ** The numeric value of an extended result code can be converted to its
    00332 ** corresponding primary result code by masking off the lower 8 bytes.
    00333 **
    00334 ** The SQLITE_OK result code will never be extended.  It will always
    00335 ** be exactly zero.
    00336 */
    00337 #define SQLITE_IOERR_READ          (SQLITE_IOERR | (1<<8))
    00338 #define SQLITE_IOERR_SHORT_READ    (SQLITE_IOERR | (2<<8))
    00339 #define SQLITE_IOERR_WRITE         (SQLITE_IOERR | (3<<8))
    00340 #define SQLITE_IOERR_FSYNC         (SQLITE_IOERR | (4<<8))
    00341 #define SQLITE_IOERR_DIR_FSYNC     (SQLITE_IOERR | (5<<8))
    00342 #define SQLITE_IOERR_TRUNCATE      (SQLITE_IOERR | (6<<8))
    00343 #define SQLITE_IOERR_FSTAT         (SQLITE_IOERR | (7<<8))
    00344 #define SQLITE_IOERR_UNLOCK        (SQLITE_IOERR | (8<<8))
    00345 #define SQLITE_IOERR_RDLOCK        (SQLITE_IOERR | (9<<8))
    00346 #define SQLITE_IOERR_DELETE        (SQLITE_IOERR | (10<<8))
    00347 #define SQLITE_IOERR_BLOCKED       (SQLITE_IOERR | (11<<8))
    00348
    00349 /*
    00350 ** CAPI3REF: Flags For File Open Operations
    00351 **
    00352 ** Combination of the following bit values are used as the
    00353 ** third argument to the [sqlite3_open_v2()] interface and
    00354 ** as fourth argument to the xOpen method of the
    00355 ** [sqlite3_vfs] object.
    00356 **
    00357 */
    00358 #define SQLITE_OPEN_READONLY         0x00000001
    00359 #define SQLITE_OPEN_READWRITE        0x00000002
    00360 #define SQLITE_OPEN_CREATE           0x00000004
    00361 #define SQLITE_OPEN_DELETEONCLOSE    0x00000008
    00362 #define SQLITE_OPEN_EXCLUSIVE        0x00000010
    00363 #define SQLITE_OPEN_MAIN_DB          0x00000100
    00364 #define SQLITE_OPEN_TEMP_DB          0x00000200
    00365 #define SQLITE_OPEN_TRANSIENT_DB     0x00000400
    00366 #define SQLITE_OPEN_MAIN_JOURNAL     0x00000800
    00367 #define SQLITE_OPEN_TEMP_JOURNAL     0x00001000
    00368 #define SQLITE_OPEN_SUBJOURNAL       0x00002000
    00369 #define SQLITE_OPEN_MASTER_JOURNAL   0x00004000
    00370
    00371 /*
    00372 ** CAPI3REF: Device Characteristics
    00373 **
    00374 ** The xDeviceCapabilities method of the [sqlite3_io_methods]
    00375 ** object returns an integer which is a vector of the following
    00376 ** bit values expressing I/O characteristics of the mass storage
    00377 ** device that holds the file that the [sqlite3_io_methods]
    00378 ** refers to.
    00379 **
    00380 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
    00381 ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
    00382 ** mean that writes of blocks that are nnn bytes in size and
    00383 ** are aligned to an address which is an integer multiple of
    00384 ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
    00385 ** that when data is appended to a file, the data is appended
    00386 ** first then the size of the file is extended, never the other
    00387 ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
    00388 ** information is written to disk in the same order as calls
    00389 ** to xWrite().
    00390 */
    00391 #define SQLITE_IOCAP_ATOMIC          0x00000001
    00392 #define SQLITE_IOCAP_ATOMIC512       0x00000002
    00393 #define SQLITE_IOCAP_ATOMIC1K        0x00000004
    00394 #define SQLITE_IOCAP_ATOMIC2K        0x00000008
    00395 #define SQLITE_IOCAP_ATOMIC4K        0x00000010
    00396 #define SQLITE_IOCAP_ATOMIC8K        0x00000020
    00397 #define SQLITE_IOCAP_ATOMIC16K       0x00000040
    00398 #define SQLITE_IOCAP_ATOMIC32K       0x00000080
    00399 #define SQLITE_IOCAP_ATOMIC64K       0x00000100
    00400 #define SQLITE_IOCAP_SAFE_APPEND     0x00000200
    00401 #define SQLITE_IOCAP_SEQUENTIAL      0x00000400
    00402
    00403 /*
    00404 ** CAPI3REF: File Locking Levels
    00405 **
    00406 ** SQLite uses one of the following integer values as the second
    00407 ** argument to calls it makes to the xLock() and xUnlock() methods
    00408 ** of an [sqlite3_io_methods] object.
    00409 */
    00410 #define SQLITE_LOCK_NONE          0
    00411 #define SQLITE_LOCK_SHARED        1
    00412 #define SQLITE_LOCK_RESERVED      2
    00413 #define SQLITE_LOCK_PENDING       3
    00414 #define SQLITE_LOCK_EXCLUSIVE     4
    00415
    00416 /*
    00417 ** CAPI3REF: Synchronization Type Flags
    00418 **
    00419 ** When SQLite invokes the xSync() method of an [sqlite3_io_methods]
    00420 ** object it uses a combination of the following integer values as
    00421 ** the second argument.
    00422 **
    00423 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
    00424 ** sync operation only needs to flush data to mass storage.  Inode
    00425 ** information need not be flushed.  The SQLITE_SYNC_NORMAL means
    00426 ** to use normal fsync() semantics.  The SQLITE_SYNC_FULL flag means
    00427 ** to use Mac OS-X style fullsync instead of fsync().
    00428 */
    00429 #define SQLITE_SYNC_NORMAL        0x00002
    00430 #define SQLITE_SYNC_FULL          0x00003
    00431 #define SQLITE_SYNC_DATAONLY      0x00010
    00432
    00433
    00434 /*
    00435 ** CAPI3REF: OS Interface Open File Handle
    00436 **
    00437 ** An [sqlite3_file] object represents an open file in the OS
    00438 ** interface layer.  Individual OS interface implementations will
    00439 ** want to subclass this object by appending additional fields
    00440 ** for their own use.  The pMethods entry is a pointer to an
    00441 ** [sqlite3_io_methods] object that defines methods for performing
    00442 ** I/O operations on the open file.
    00443 */
    00444 typedef struct sqlite3_file sqlite3_file;
    00445 struct sqlite3_file {
    00446   const struct sqlite3_io_methods *pMethods;  /* Methods for an open file */
    00447 };
    00448
    00449 /*
    00450 ** CAPI3REF: OS Interface File Virtual Methods Object
    00451 **
    00452 ** Every file opened by the [sqlite3_vfs] xOpen method contains a pointer to
    00453 ** an instance of the this object.  This object defines the
    00454 ** methods used to perform various operations against the open file.
    00455 **
    00456 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
    00457 ** [SQLITE_SYNC_FULL].  The first choice is the normal fsync().
    00458 *  The second choice is an
    00459 ** OS-X style fullsync.  The SQLITE_SYNC_DATA flag may be ORed in to
    00460 ** indicate that only the data of the file and not its inode needs to be
    00461 ** synced.
    00462 **
    00463 ** The integer values to xLock() and xUnlock() are one of
    00464 ** <ul>
    00465 ** <li> [SQLITE_LOCK_NONE],
    00466 ** <li> [SQLITE_LOCK_READ],
    00467 ** <li> [SQLITE_LOCK_RESERVED],
    00468 ** <li> [SQLITE_LOCK_PENDING], or
    00469 ** <li> [SQLITE_LOCK_EXCLUSIVE].
    00470 ** </ul>
    00471 ** xLock() increases the lock. xUnlock() decreases the lock.
    00472 ** The xCheckReservedLock() method looks
    00473 ** to see if any database connection, either in this
    00474 ** process or in some other process, is holding an RESERVED,
    00475 ** PENDING, or EXCLUSIVE lock on the file.  It returns true
    00476 ** if such a lock exists and false if not.
    00477 **
    00478 ** The xFileControl() method is a generic interface that allows custom
    00479 ** VFS implementations to directly control an open file using the
    00480 ** [sqlite3_file_control()] interface.  The second "op" argument
    00481 ** is an integer opcode.   The third
    00482 ** argument is a generic pointer which is intended to be a pointer
    00483 ** to a structure that may contain arguments or space in which to
    00484 ** write return values.  Potential uses for xFileControl() might be
    00485 ** functions to enable blocking locks with timeouts, to change the
    00486 ** locking strategy (for example to use dot-file locks), to inquire
    00487 ** about the status of a lock, or to break stale locks.  The SQLite
    00488 ** core reserves opcodes less than 100 for its own use.
    00489 ** A [SQLITE_FCNTL_LOCKSTATE | list of opcodes] less than 100 is available.
    00490 ** Applications that define a custom xFileControl method should use opcodes
    00491 ** greater than 100 to avoid conflicts.
    00492 **
    00493 ** The xSectorSize() method returns the sector size of the
    00494 ** device that underlies the file.  The sector size is the
    00495 ** minimum write that can be performed without disturbing
    00496 ** other bytes in the file.  The xDeviceCharacteristics()
    00497 ** method returns a bit vector describing behaviors of the
    00498 ** underlying device:
    00499 **
    00500 ** <ul>
    00501 ** <li> [SQLITE_IOCAP_ATOMIC]
    00502 ** <li> [SQLITE_IOCAP_ATOMIC512]
    00503 ** <li> [SQLITE_IOCAP_ATOMIC1K]
    00504 ** <li> [SQLITE_IOCAP_ATOMIC2K]
    00505 ** <li> [SQLITE_IOCAP_ATOMIC4K]
    00506 ** <li> [SQLITE_IOCAP_ATOMIC8K]
    00507 ** <li> [SQLITE_IOCAP_ATOMIC16K]
    00508 ** <li> [SQLITE_IOCAP_ATOMIC32K]
    00509 ** <li> [SQLITE_IOCAP_ATOMIC64K]
    00510 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
    00511 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
    00512 ** </ul>
    00513 **
    00514 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
    00515 ** any size are atomic.  The SQLITE_IOCAP_ATOMICnnn values
    00516 ** mean that writes of blocks that are nnn bytes in size and
    00517 ** are aligned to an address which is an integer multiple of
    00518 ** nnn are atomic.  The SQLITE_IOCAP_SAFE_APPEND value means
    00519 ** that when data is appended to a file, the data is appended
    00520 ** first then the size of the file is extended, never the other
    00521 ** way around.  The SQLITE_IOCAP_SEQUENTIAL property means that
    00522 ** information is written to disk in the same order as calls
    00523 ** to xWrite().
    00524 */
    00525 typedef struct sqlite3_io_methods sqlite3_io_methods;
    00526 struct sqlite3_io_methods {
    00527   int iVersion;
    00528   int (*xClose)(sqlite3_file*);
    00529   int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite_int64 iOfst);
    00530   int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite_int64 iOfst);
    00531   int (*xTruncate)(sqlite3_file*, sqlite_int64 size);
    00532   int (*xSync)(sqlite3_file*, int flags);
    00533   int (*xFileSize)(sqlite3_file*, sqlite_int64 *pSize);
    00534   int (*xLock)(sqlite3_file*, int);
    00535   int (*xUnlock)(sqlite3_file*, int);
    00536   int (*xCheckReservedLock)(sqlite3_file*);
    00537   int (*xFileControl)(sqlite3_file*, int op, void *pArg);
    00538   int (*xSectorSize)(sqlite3_file*);
    00539   int (*xDeviceCharacteristics)(sqlite3_file*);
    00540   /* Additional methods may be added in future releases */
    00541 };
    00542
    00543 /*
    00544 ** CAPI3REF: Standard File Control Opcodes
    00545 **
    00546 ** These integer constants are opcodes for the xFileControl method
    00547 ** of the [sqlite3_io_methods] object and to the [sqlite3_file_control()]
    00548 ** interface.
    00549 **
    00550 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging.  This
    00551 ** opcode cases the xFileControl method to write the current state of
    00552 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
    00553 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
    00554 ** into an integer that the pArg argument points to.  This capability
    00555 ** is used during testing and only needs to be supported when SQLITE_TEST
    00556 ** is defined.
    00557 */
    00558 #define SQLITE_FCNTL_LOCKSTATE        1
    00559
    00560 /*
    00561 ** CAPI3REF: Mutex Handle
    00562 **
    00563 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
    00564 ** abstract type for a mutex object.  The SQLite core never looks
    00565 ** at the internal representation of an [sqlite3_mutex].  It only
    00566 ** deals with pointers to the [sqlite3_mutex] object.
    00567 **
    00568 ** Mutexes are created using [sqlite3_mutex_alloc()].
    00569 */
    00570 typedef struct sqlite3_mutex sqlite3_mutex;
    00571
    00572 /*
    00573 ** CAPI3REF: OS Interface Object
    00574 **
    00575 ** An instance of this object defines the interface between the
    00576 ** SQLite core and the underlying operating system.  The "vfs"
    00577 ** in the name of the object stands for "virtual file system".
    00578 **
    00579 ** The iVersion field is initially 1 but may be larger for future
    00580 ** versions of SQLite.  Additional fields may be appended to this
    00581 ** object when the iVersion value is increased.
    00582 **
    00583 ** The szOsFile field is the size of the subclassed [sqlite3_file]
    00584 ** structure used by this VFS.  mxPathname is the maximum length of
    00585 ** a pathname in this VFS.
    00586 **
    00587 ** Registered vfs modules are kept on a linked list formed by
    00588 ** the pNext pointer.  The [sqlite3_register_vfs()]
    00589 ** and [sqlite3_unregister_vfs()] interfaces manage this list
    00590 ** in a thread-safe way.  The [sqlite3_find_vfs()] interface
    00591 ** searches the list.
    00592 **
    00593 ** The pNext field is the only fields in the sqlite3_vfs
    00594 ** structure that SQLite will ever modify.  SQLite will only access
    00595 ** or modify this field while holding a particular static mutex.
    00596 ** The application should never modify anything within the sqlite3_vfs
    00597 ** object once the object has been registered.
    00598 **
    00599 ** The zName field holds the name of the VFS module.  The name must
    00600 ** be unique across all VFS modules.
    00601 **
    00602 ** SQLite will guarantee that the zFilename string passed to
    00603 ** xOpen() is a full pathname as generated by xFullPathname() and
    00604 ** that the string will be valid and unchanged until xClose() is
    00605 ** called.  So the [sqlite3_file] can store a pointer to the
    00606 ** filename if it needs to remember the filename for some reason.
    00607 **
    00608 ** The flags argument to xOpen() is a copy of the flags argument
    00609 ** to [sqlite3_open_v2()].  If [sqlite3_open()] or [sqlite3_open16()]
    00610 ** is used, then flags is [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
    00611 ** If xOpen() opens a file read-only then it sets *pOutFlags to
    00612 ** include [SQLITE_OPEN_READONLY].  Other bits in *pOutFlags may be
    00613 ** set.
    00614 **
    00615 ** SQLite will also add one of the following flags to the xOpen()
    00616 ** call, depending on the object being opened:
    00617 **
    00618 ** <ul>
    00619 ** <li>  [SQLITE_OPEN_MAIN_DB]
    00620 ** <li>  [SQLITE_OPEN_MAIN_JOURNAL]
    00621 ** <li>  [SQLITE_OPEN_TEMP_DB]
    00622 ** <li>  [SQLITE_OPEN_TEMP_JOURNAL]
    00623 ** <li>  [SQLITE_OPEN_TRANSIENT_DB]
    00624 ** <li>  [SQLITE_OPEN_SUBJOURNAL]
    00625 ** <li>  [SQLITE_OPEN_MASTER_JOURNAL]
    00626 ** </ul>
    00627 **
    00628 ** The file I/O implementation can use the object type flags to
    00629 ** changes the way it deals with files.  For example, an application
    00630 ** that does not care about crash recovery or rollback, might make
    00631 ** the open of a journal file a no-op.  Writes to this journal are
    00632 ** also a no-op.  Any attempt to read the journal return SQLITE_IOERR.
    00633 ** Or the implementation might recognize the a database file will
    00634 ** be doing page-aligned sector reads and writes in a random order
    00635 ** and set up its I/O subsystem accordingly.
    00636 **
    00637 ** SQLite might also add one of the following flags to the xOpen
    00638 ** method:
    00639 **
    00640 ** <ul>
    00641 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
    00642 ** <li> [SQLITE_OPEN_EXCLUSIVE]
    00643 ** </ul>
    00644 **
    00645 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
    00646 ** deleted when it is closed.  This will always be set for TEMP
    00647 ** databases and journals and for subjournals.  The
    00648 ** [SQLITE_OPEN_EXCLUSIVE] flag means the file should be opened
    00649 ** for exclusive access.  This flag is set for all files except
    00650 ** for the main database file.
    00651 **
    00652 ** Space to hold the  [sqlite3_file] structure passed as the third
    00653 ** argument to xOpen is allocated by caller (the SQLite core).
    00654 ** szOsFile bytes are allocated for this object.  The xOpen method
    00655 ** fills in the allocated space.
    00656 **
    00657 ** The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
    00658 ** to test for the existance of a file,
    00659 ** or [SQLITE_ACCESS_READWRITE] to test to see
    00660 ** if a file is readable and writable, or [SQLITE_ACCESS_READ]
    00661 ** to test to see if a file is at least readable.  The file can be a
    00662 ** directory.
    00663 **
    00664 ** SQLite will always allocate at least mxPathname+1 byte for
    00665 ** the output buffers for xGetTempName and xFullPathname.
    00666 **
    00667 ** The xRandomness(), xSleep(), and xCurrentTime() interfaces
    00668 ** are not strictly a part of the filesystem, but they are
    00669 ** included in the VFS structure for completeness.
    00670 ** The xRandomness() function attempts to return nBytes bytes
    00671 ** of good-quality randomness into zOut.  The return value is
    00672 ** the actual number of bytes of randomness obtained.  The
    00673 ** xSleep() method cause the calling thread to sleep for at
    00674 ** least the number of microseconds given.  The xCurrentTime()
    00675 ** method returns a Julian Day Number for the current date and
    00676 ** time.
    00677 */
    00678 typedef struct sqlite3_vfs sqlite3_vfs;
    00679 struct sqlite3_vfs {
    00680   int iVersion;            /* Structure version number */
    00681   int szOsFile;            /* Size of subclassed sqlite3_file */
    00682   int mxPathname;          /* Maximum file pathname length */
    00683   sqlite3_vfs *pNext;      /* Next registered VFS */
    00684   const char *zName;       /* Name of this virtual file system */
    00685   void *pAppData;          /* Pointer to application-specific data */
    00686   int (*xOpen)(sqlite3_vfs*, const char *zName, sqlite3_file*,
    00687                int flags, int *pOutFlags);
    00688   int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
    00689   int (*xAccess)(sqlite3_vfs*, const char *zName, int flags);
    00690   int (*xGetTempName)(sqlite3_vfs*, char *zOut);
    00691   int (*xFullPathname)(sqlite3_vfs*, const char *zName, char *zOut);
    00692   void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
    00693   void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
    00694   void *(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol);
    00695   void (*xDlClose)(sqlite3_vfs*, void*);
    00696   int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
    00697   int (*xSleep)(sqlite3_vfs*, int microseconds);
    00698   int (*xCurrentTime)(sqlite3_vfs*, double*);
    00699   /* New fields may be appended in figure versions.  The iVersion
    00700   ** value will increment whenever this happens. */
    00701 };
    00702
    00703 /*
    00704 ** CAPI3REF: Flags for the xAccess VFS method
    00705 **
    00706 ** These integer constants can be used as the third parameter to
    00707 ** the xAccess method of an [sqlite3_vfs] object.  They determine
    00708 ** the kind of what kind of permissions the xAccess method is
    00709 ** looking for.  With SQLITE_ACCESS_EXISTS, the xAccess method
    00710 ** simply checks to see if the file exists.  With SQLITE_ACCESS_READWRITE,
    00711 ** the xAccess method checks to see if the file is both readable
    00712 ** and writable.  With SQLITE_ACCESS_READ the xAccess method
    00713 ** checks to see if the file is readable.
    00714 */
    00715 #define SQLITE_ACCESS_EXISTS    0
    00716 #define SQLITE_ACCESS_READWRITE 1
    00717 #define SQLITE_ACCESS_READ      2
    00718
    00719 /*
    00720 ** CAPI3REF: Enable Or Disable Extended Result Codes
    00721 **
    00722 ** This routine enables or disables the
    00723 ** [SQLITE_IOERR_READ | extended result codes] feature.
    00724 ** By default, SQLite API routines return one of only 26 integer
    00725 ** [SQLITE_OK | result codes].  When extended result codes
    00726 ** are enabled by this routine, the repetoire of result codes can be
    00727 ** much larger and can (hopefully) provide more detailed information
    00728 ** about the cause of an error.
    00729 **
    00730 ** The second argument is a boolean value that turns extended result
    00731 ** codes on and off.  Extended result codes are off by default for
    00732 ** backwards compatibility with older versions of SQLite.
    00733 */
    00734 int sqlite3_extended_result_codes(sqlite3*, int onoff);
    00735
    00736 /*
    00737 ** CAPI3REF: Last Insert Rowid
    00738 **
    00739 ** Each entry in an SQLite table has a unique 64-bit signed integer key
    00740 ** called the "rowid". The rowid is always available as an undeclared
    00741 ** column named ROWID, OID, or _ROWID_.  If the table has a column of
    00742 ** type INTEGER PRIMARY KEY then that column is another an alias for the
    00743 ** rowid.
    00744 **
    00745 ** This routine returns the rowid of the most recent INSERT into
    00746 ** the database from the database connection given in the first
    00747 ** argument.  If no inserts have ever occurred on this database
    00748 ** connection, zero is returned.
    00749 **
    00750 ** If an INSERT occurs within a trigger, then the rowid of the
    00751 ** inserted row is returned by this routine as long as the trigger
    00752 ** is running.  But once the trigger terminates, the value returned
    00753 ** by this routine reverts to the last value inserted before the
    00754 ** trigger fired.
    00755 **
    00756 ** If another thread does a new insert on the same database connection
    00757 ** while this routine is running and thus changes the last insert rowid,
    00758 ** then the return value of this routine is undefined.
    00759 */
    00760 sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
    00761
    00762 /*
    00763 ** CAPI3REF: Count The Number Of Rows Modified
    00764 **
    00765 ** This function returns the number of database rows that were changed
    00766 ** (or inserted or deleted) by the most recent SQL statement.  Only
    00767 ** changes that are directly specified by the INSERT, UPDATE, or
    00768 ** DELETE statement are counted.  Auxiliary changes caused by
    00769 ** triggers are not counted.  Use the [sqlite3_total_changes()] function
    00770 ** to find the total number of changes including changes caused by triggers.
    00771 **
    00772 ** Within the body of a trigger, the sqlite3_changes() interface can be
    00773 ** called to find the number of
    00774 ** changes in the most recently completed INSERT, UPDATE, or DELETE
    00775 ** statement within the body of the trigger.
    00776 **
    00777 ** All changes are counted, even if they were later undone by a
    00778 ** ROLLBACK or ABORT.  Except, changes associated with creating and
    00779 ** dropping tables are not counted.
    00780 **
    00781 ** If a callback invokes [sqlite3_exec()] or [sqlite3_step()] recursively,
    00782 ** then the changes in the inner, recursive call are counted together
    00783 ** with the changes in the outer call.
    00784 **
    00785 ** SQLite implements the command "DELETE FROM table" without a WHERE clause
    00786 ** by dropping and recreating the table.  (This is much faster than going
    00787 ** through and deleting individual elements from the table.)  Because of
    00788 ** this optimization, the change count for "DELETE FROM table" will be
    00789 ** zero regardless of the number of elements that were originally in the
    00790 ** table. To get an accurate count of the number of rows deleted, use
    00791 ** "DELETE FROM table WHERE 1" instead.
    00792 **
    00793 ** If another thread makes changes on the same database connection
    00794 ** while this routine is running then the return value of this routine
    00795 ** is undefined.
    00796 */
    00797 int sqlite3_changes(sqlite3*);
    00798
    00799 /*
    00800 ** CAPI3REF: Total Number Of Rows Modified
    00801 ***
    00802 ** This function returns the number of database rows that have been
    00803 ** modified by INSERT, UPDATE or DELETE statements since the database handle
    00804 ** was opened. This includes UPDATE, INSERT and DELETE statements executed
    00805 ** as part of trigger programs. All changes are counted as soon as the
    00806 ** statement that makes them is completed (when the statement handle is
    00807 ** passed to [sqlite3_reset()] or [sqlite3_finalise()]).
    00808 **
    00809 ** See also the [sqlite3_change()] interface.
    00810 **
    00811 ** SQLite implements the command "DELETE FROM table" without a WHERE clause
    00812 ** by dropping and recreating the table.  (This is much faster than going
    00813 ** through and deleting individual elements form the table.)  Because of
    00814 ** this optimization, the change count for "DELETE FROM table" will be
    00815 ** zero regardless of the number of elements that were originally in the
    00816 ** table. To get an accurate count of the number of rows deleted, use
    00817 ** "DELETE FROM table WHERE 1" instead.
    00818 **
    00819 ** If another thread makes changes on the same database connection
    00820 ** while this routine is running then the return value of this routine
    00821 ** is undefined.
    00822 */
    00823 int sqlite3_total_changes(sqlite3*);
    00824
    00825 /*
    00826 ** CAPI3REF: Interrupt A Long-Running Query
    00827 **
    00828 ** This function causes any pending database operation to abort and
    00829 ** return at its earliest opportunity.  This routine is typically
    00830 ** called in response to a user action such as pressing "Cancel"
    00831 ** or Ctrl-C where the user wants a long query operation to halt
    00832 ** immediately.
    00833 **
    00834 ** It is safe to call this routine from a thread different from the
    00835 ** thread that is currently running the database operation.  But it
    00836 ** is not safe to call this routine with a database connection that
    00837 ** is closed or might close before sqlite3_interrupt() returns.
    00838 **
    00839 ** The SQL operation that is interrupted will return [SQLITE_INTERRUPT].
    00840 ** If an interrupted operation was an update that is inside an
    00841 ** explicit transaction, then the entire transaction will be rolled
    00842 ** back automatically.
    00843 */
    00844 void sqlite3_interrupt(sqlite3*);
    00845
    00846 /*
    00847 ** CAPI3REF: Determine If An SQL Statement Is Complete
    00848 **
    00849 ** These functions return true if the given input string comprises
    00850 ** one or more complete SQL statements. For the sqlite3_complete() call,
    00851 ** the parameter must be a nul-terminated UTF-8 string. For
    00852 ** sqlite3_complete16(), a nul-terminated machine byte order UTF-16 string
    00853 ** is required.
    00854 **
    00855 ** These routines are useful for command-line input to determine if the
    00856 ** currently entered text forms one or more complete SQL statements or
    00857 ** if additional input is needed before sending the statements into
    00858 ** SQLite for parsing. The algorithm is simple.  If the
    00859 ** last token other than spaces and comments is a semicolon, then return
    00860 ** true.  Actually, the algorithm is a little more complicated than that
    00861 ** in order to deal with triggers, but the basic idea is the same:  the
    00862 ** statement is not complete unless it ends in a semicolon.
    00863 */
    00864 int sqlite3_complete(const char *sql);
    00865 int sqlite3_complete16(const void *sql);
    00866
    00867 /*
    00868 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
    00869 **
    00870 ** This routine identifies a callback function that might be invoked
    00871 ** whenever an attempt is made to open a database table
    00872 ** that another thread or process has locked.
    00873 ** If the busy callback is NULL, then [SQLITE_BUSY]
    00874 ** (or sometimes [SQLITE_IOERR_BLOCKED])
    00875 ** is returned immediately upon encountering the lock.
    00876 ** If the busy callback is not NULL, then the
    00877 ** callback will be invoked with two arguments.  The
    00878 ** first argument to the handler is a copy of the void* pointer which
    00879 ** is the third argument to this routine.  The second argument to
    00880 ** the handler is the number of times that the busy handler has
    00881 ** been invoked for this locking event. If the
    00882 ** busy callback returns 0, then no additional attempts are made to
    00883 ** access the database and [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED] is returned.
    00884 ** If the callback returns non-zero, then another attempt is made to open the
    00885 ** database for reading and the cycle repeats.
    00886 **
    00887 ** The presence of a busy handler does not guarantee that
    00888 ** it will be invoked when there is lock contention.
    00889 ** If SQLite determines that invoking the busy handler could result in
    00890 ** a deadlock, it will return [SQLITE_BUSY] instead.
    00891 ** Consider a scenario where one process is holding a read lock that
    00892 ** it is trying to promote to a reserved lock and
    00893 ** a second process is holding a reserved lock that it is trying
    00894 ** to promote to an exclusive lock.  The first process cannot proceed
    00895 ** because it is blocked by the second and the second process cannot
    00896 ** proceed because it is blocked by the first.  If both processes
    00897 ** invoke the busy handlers, neither will make any progress.  Therefore,
    00898 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
    00899 ** will induce the first process to release its read lock and allow
    00900 ** the second process to proceed.
    00901 **
    00902 ** The default busy callback is NULL.
    00903 **
    00904 ** The [SQLITE_BUSY] error is converted to [SQLITE_IOERR_BLOCKED] when
    00905 ** SQLite is in the middle of a large transaction where all the
    00906 ** changes will not fit into the in-memory cache.  SQLite will
    00907 ** already hold a RESERVED lock on the database file, but it needs
    00908 ** to promote this lock to EXCLUSIVE so that it can spill cache
    00909 ** pages into the database file without harm to concurrent
    00910 ** readers.  If it is unable to promote the lock, then the in-memory
    00911 ** cache will be left in an inconsistent state and so the error
    00912 ** code is promoted from the relatively benign [SQLITE_BUSY] to
    00913 ** the more severe [SQLITE_IOERR_BLOCKED].  This error code promotion
    00914 ** forces an automatic rollback of the changes. See the
    00915 ** <a href="http://www.sqlite.org/cvstrac/wiki?p=CorruptionFollowingBusyError">
    00916 ** CorruptionFollowingBusyError</a> wiki page for a discussion of why
    00917 ** this is important.
    00918 **
    00919 ** Sqlite is re-entrant, so the busy handler may start a new query.
    00920 ** (It is not clear why anyone would every want to do this, but it
    00921 ** is allowed, in theory.)  But the busy handler may not close the
    00922 ** database.  Closing the database from a busy handler will delete
    00923 ** data structures out from under the executing query and will
    00924 ** probably result in a segmentation fault or other runtime error.
    00925 **
    00926 ** There can only be a single busy handler defined for each database
    00927 ** connection.  Setting a new busy handler clears any previous one.
    00928 ** Note that calling [sqlite3_busy_timeout()] will also set or clear
    00929 ** the busy handler.
    00930 **
    00931 ** When operating in [sqlite3_enable_shared_cache | shared cache mode],
    00932 ** only a single busy handler can be defined for each database file.
    00933 ** So if two database connections share a single cache, then changing
    00934 ** the busy handler on one connection will also change the busy
    00935 ** handler in the other connection.  The busy handler is invoked
    00936 ** in the thread that was running when the SQLITE_BUSY was hit.
    00937 */
    00938 int sqlite3_busy_handler(sqlite3*, int(*)(void*,int), void*);
    00939
    00940 /*
    00941 ** CAPI3REF: Set A Busy Timeout
    00942 **
    00943 ** This routine sets a busy handler that sleeps for a while when a
    00944 ** table is locked.  The handler will sleep multiple times until
    00945 ** at least "ms" milliseconds of sleeping have been done.  After
    00946 ** "ms" milliseconds of sleeping, the handler returns 0 which
    00947 ** causes [sqlite3_step()] to return [SQLITE_BUSY] or [SQLITE_IOERR_BLOCKED].
    00948 **
    00949 ** Calling this routine with an argument less than or equal to zero
    00950 ** turns off all busy handlers.
    00951 **
    00952 ** There can only be a single busy handler for a particular database
    00953 ** connection.  If another busy handler was defined
    00954 ** (using [sqlite3_busy_handler()]) prior to calling
    00955 ** this routine, that other busy handler is cleared.
    00956 */
    00957 int sqlite3_busy_timeout(sqlite3*, int ms);
    00958
    00959 /*
    00960 ** CAPI3REF: Convenience Routines For Running Queries
    00961 **
    00962 ** This next routine is a convenience wrapper around [sqlite3_exec()].
    00963 ** Instead of invoking a user-supplied callback for each row of the
    00964 ** result, this routine remembers each row of the result in memory
    00965 ** obtained from [sqlite3_malloc()], then returns all of the result after the
    00966 ** query has finished.
    00967 **
    00968 ** As an example, suppose the query result where this table:
    00969 **
    00970 ** <blockquote><pre>
    00971 **        Name        | Age
    00972 **        -----------------------
    00973 **        Alice       | 43
    00974 **        Bob         | 28
    00975 **        Cindy       | 21
    00976 ** </pre></blockquote>
    00977 **
    00978 ** If the 3rd argument were &azResult then after the function returns
    00979 ** azResult will contain the following data:
    00980 **
    00981 ** <blockquote><pre>
    00982 **        azResult&#91;0] = "Name";
    00983 **        azResult&#91;1] = "Age";
    00984 **        azResult&#91;2] = "Alice";
    00985 **        azResult&#91;3] = "43";
    00986 **        azResult&#91;4] = "Bob";
    00987 **        azResult&#91;5] = "28";
    00988 **        azResult&#91;6] = "Cindy";
    00989 **        azResult&#91;7] = "21";
    00990 ** </pre></blockquote>
    00991 **
    00992 ** Notice that there is an extra row of data containing the column
    00993 ** headers.  But the *nrow return value is still 3.  *ncolumn is
    00994 ** set to 2.  In general, the number of values inserted into azResult
    00995 ** will be ((*nrow) + 1)*(*ncolumn).
    00996 **
    00997 ** After the calling function has finished using the result, it should
    00998 ** pass the result data pointer to sqlite3_free_table() in order to
    00999 ** release the memory that was malloc-ed.  Because of the way the
    01000 ** [sqlite3_malloc()] happens, the calling function must not try to call
    01001 ** [sqlite3_free()] directly.  Only [sqlite3_free_table()] is able to release
    01002 ** the memory properly and safely.
    01003 **
    01004 ** The return value of this routine is the same as from [sqlite3_exec()].
    01005 */
    01006 int sqlite3_get_table(
    01007   sqlite3*,              /* An open database */
    01008   const char *sql,       /* SQL to be executed */
    01009   char ***resultp,       /* Result written to a char *[]  that this points to */
    01010   int *nrow,             /* Number of result rows written here */
    01011   int *ncolumn,          /* Number of result columns written here */
    01012   char **errmsg          /* Error msg written here */
    01013 );
    01014 void sqlite3_free_table(char **result);
    01015
    01016 /*
    01017 ** CAPI3REF: Formatted String Printing Functions
    01018 **
    01019 ** These routines are workalikes of the "printf()" family of functions
    01020 ** from the standard C library.
    01021 **
    01022 ** The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
    01023 ** results into memory obtained from [sqlite3_malloc()].
    01024 ** The strings returned by these two routines should be
    01025 ** released by [sqlite3_free()].  Both routines return a
    01026 ** NULL pointer if [sqlite3_malloc()] is unable to allocate enough
    01027 ** memory to hold the resulting string.
    01028 **
    01029 ** In sqlite3_snprintf() routine is similar to "snprintf()" from
    01030 ** the standard C library.  The result is written into the
    01031 ** buffer supplied as the second parameter whose size is given by
    01032 ** the first parameter.  Note that the order of the
    01033 ** first two parameters is reversed from snprintf().  This is an
    01034 ** historical accident that cannot be fixed without breaking
    01035 ** backwards compatibility.  Note also that sqlite3_snprintf()
    01036 ** returns a pointer to its buffer instead of the number of
    01037 ** characters actually written into the buffer.  We admit that
    01038 ** the number of characters written would be a more useful return
    01039 ** value but we cannot change the implementation of sqlite3_snprintf()
    01040 ** now without breaking compatibility.
    01041 **
    01042 ** As long as the buffer size is greater than zero, sqlite3_snprintf()
    01043 ** guarantees that the buffer is always zero-terminated.  The first
    01044 ** parameter "n" is the total size of the buffer, including space for
    01045 ** the zero terminator.  So the longest string that can be completely
    01046 ** written will be n-1 characters.
    01047 **
    01048 ** These routines all implement some additional formatting
    01049 ** options that are useful for constructing SQL statements.
    01050 ** All of the usual printf formatting options apply.  In addition, there
    01051 ** is are "%q", "%Q", and "%z" options.
    01052 **
    01053 ** The %q option works like %s in that it substitutes a null-terminated
    01054 ** string from the argument list.  But %q also doubles every '\'' character.
    01055 ** %q is designed for use inside a string literal.  By doubling each '\''
    01056 ** character it escapes that character and allows it to be inserted into
    01057 ** the string.
    01058 **
    01059 ** For example, so some string variable contains text as follows:
    01060 **
    01061 ** <blockquote><pre>
    01062 **  char *zText = "It's a happy day!";
    01063 ** </pre></blockquote>
    01064 **
    01065 ** One can use this text in an SQL statement as follows:
    01066 **
    01067 ** <blockquote><pre>
    01068 **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES('%q')", zText);
    01069 **  sqlite3_exec(db, zSQL, 0, 0, 0);
    01070 **  sqlite3_free(zSQL);
    01071 ** </pre></blockquote>
    01072 **
    01073 ** Because the %q format string is used, the '\'' character in zText
    01074 ** is escaped and the SQL generated is as follows:
    01075 **
    01076 ** <blockquote><pre>
    01077 **  INSERT INTO table1 VALUES('It''s a happy day!')
    01078 ** </pre></blockquote>
    01079 **
    01080 ** This is correct.  Had we used %s instead of %q, the generated SQL
    01081 ** would have looked like this:
    01082 **
    01083 ** <blockquote><pre>
    01084 **  INSERT INTO table1 VALUES('It's a happy day!');
    01085 ** </pre></blockquote>
    01086 **
    01087 ** This second example is an SQL syntax error.  As a general rule you
    01088 ** should always use %q instead of %s when inserting text into a string
    01089 ** literal.
    01090 **
    01091 ** The %Q option works like %q except it also adds single quotes around
    01092 ** the outside of the total string.  Or if the parameter in the argument
    01093 ** list is a NULL pointer, %Q substitutes the text "NULL" (without single
    01094 ** quotes) in place of the %Q option.  So, for example, one could say:
    01095 **
    01096 ** <blockquote><pre>
    01097 **  char *zSQL = sqlite3_mprintf("INSERT INTO table VALUES(%Q)", zText);
    01098 **  sqlite3_exec(db, zSQL, 0, 0, 0);
    01099 **  sqlite3_free(zSQL);
    01100 ** </pre></blockquote>
    01101 **
    01102 ** The code above will render a correct SQL statement in the zSQL
    01103 ** variable even if the zText variable is a NULL pointer.
    01104 **
    01105 ** The "%z" formatting option works exactly like "%s" with the
    01106 ** addition that after the string has been read and copied into
    01107 ** the result, [sqlite3_free()] is called on the input string.
    01108 */
    01109 char *sqlite3_mprintf(const char*,...);
    01110 char *sqlite3_vmprintf(const char*, va_list);
    01111 char *sqlite3_snprintf(int,char*,const char*, ...);
    01112
    01113 /*
    01114 ** CAPI3REF: Memory Allocation Subsystem
    01115 **
    01116 ** The SQLite core uses these three routines for all of its own
    01117 ** internal memory allocation needs. The default implementation
    01118 ** of the memory allocation subsystem uses the malloc(), realloc()
    01119 ** and free() provided by the standard C library.  However, if
    01120 ** SQLite is compiled with the following C preprocessor macro
    01121 **
    01122 ** <blockquote> SQLITE_OMIT_MEMORY_ALLOCATION </blockquote>
    01123 **
    01124 ** then no implementation is provided for these routines by
    01125 ** SQLite.  The application that links against SQLite is
    01126 ** expected to provide its own implementation.  If the application
    01127 ** does provide its own implementation for these routines, then
    01128 ** it must also provide an implementation for
    01129 ** [sqlite3_memory_alarm()].
    01130 **
    01131 ** <b>Exception:</b> The windows OS interface layer calls
    01132 ** the system malloc() and free() directly when converting
    01133 ** filenames between the UTF-8 encoding used by SQLite
    01134 ** and whatever filename encoding is used by the particular windows
    01135 ** installation.  Memory allocation errors are detected, but
    01136 ** they are reported back as [SQLITE_CANTOPEN] or
    01137 ** [SQLITE_IOERR] rather than [SQLITE_NOMEM].
    01138 */
    01139 void *sqlite3_malloc(int);
    01140 void *sqlite3_realloc(void*, int);
    01141 void sqlite3_free(void*);
    01142
    01143 /*
    01144 ** CAPI3REF: Memory Allocator Statistics
    01145 **
    01146 ** In addition to the basic three allocation routines
    01147 ** [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()],
    01148 ** the memory allocation subsystem included with the SQLite
    01149 ** sources provides the interfaces shown below.
    01150 **
    01151 ** The first of these two routines returns the amount of memory
    01152 ** currently outstanding (malloced but not freed).  The second
    01153 ** returns the largest instantaneous amount of outstanding
    01154 ** memory.  The highwater mark is reset if the argument is
    01155 ** true.  The SQLite core does not use either of these routines
    01156 ** and so they do not have to be implemented by the application
    01157 ** if SQLITE_OMIT_MEMORY_ALLOCATION is defined.  These routines
    01158 ** are provided by the default memory subsystem for diagnostic
    01159 ** purposes.
    01160 */
    01161 sqlite3_int64 sqlite3_memory_used(void);
    01162 sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
    01163
    01164 /*
    01165 ** CAPI3REF: Memory Allocation Alarms
    01166 **
    01167 ** The [sqlite3_memory_alarm] routine is used to register
    01168 ** a callback on memory allocation events.
    01169 **
    01170 ** This routine registers or clears a callbacks that fires when
    01171 ** the amount of memory allocated exceeds iThreshold.  Only
    01172 ** a single callback can be registered at a time.  Each call
    01173 ** to [sqlite3_memory_alarm()] overwrites the previous callback.
    01174 ** The callback is disabled by setting xCallback to a NULL
    01175 ** pointer.
    01176 **
    01177 ** The parameters to the callback are the pArg value, the
    01178 ** amount of memory currently in use, and the size of the
    01179 ** allocation that provoked the callback.  The callback will
    01180 ** presumably invoke [sqlite3_free()] to free up memory space.
    01181 ** The callback may invoke [sqlite3_malloc()] or [sqlite3_realloc()]
    01182 ** but if it does, no additional callbacks will be invoked by
    01183 ** the recursive calls.
    01184 **
    01185 ** The [sqlite3_soft_heap_limit()] interface works by registering
    01186 ** a memory alarm at the soft heap limit and invoking
    01187 ** [sqlite3_release_memory()] in the alarm callback.  Application
    01188 ** programs should not attempt to use the [sqlite3_memory_alarm()]
    01189 ** interface because doing so will interfere with the
    01190 ** [sqlite3_soft_heap_limit()] module.  This interface is exposed
    01191 ** only so that applications can provide their own
    01192 ** alternative implementation when the SQLite core is
    01193 ** compiled with SQLITE_OMIT_MEMORY_ALLOCATION.
    01194 */
    01195 int sqlite3_memory_alarm(
    01196   void(*xCallback)(void *pArg, sqlite3_int64 used, int N),
    01197   void *pArg,
    01198   sqlite3_int64 iThreshold
    01199 );
    01200
    01201
    01202 /*
    01203 ** CAPI3REF: Compile-Time Authorization Callbacks
    01204 ***
    01205 ** This routine registers a authorizer callback with the SQLite library.
    01206 ** The authorizer callback is invoked as SQL statements are being compiled
    01207 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
    01208 ** [sqlite3_prepare16()] and [sqlite3_prepare16_v2()].  At various
    01209 ** points during the compilation process, as logic is being created
    01210 ** to perform various actions, the authorizer callback is invoked to
    01211 ** see if those actions are allowed.  The authorizer callback should
    01212 ** return SQLITE_OK to allow the action, [SQLITE_IGNORE] to disallow the
    01213 ** specific action but allow the SQL statement to continue to be
    01214 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
    01215 ** rejected with an error.
    01216 **
    01217 ** Depending on the action, the [SQLITE_IGNORE] and [SQLITE_DENY] return
    01218 ** codes might mean something different or they might mean the same
    01219 ** thing.  If the action is, for example, to perform a delete opertion,
    01220 ** then [SQLITE_IGNORE] and [SQLITE_DENY] both cause the statement compilation
    01221 ** to fail with an error.  But if the action is to read a specific column
    01222 ** from a specific table, then [SQLITE_DENY] will cause the entire
    01223 ** statement to fail but [SQLITE_IGNORE] will cause a NULL value to be
    01224 ** read instead of the actual column value.
    01225 **
    01226 ** The first parameter to the authorizer callback is a copy of
    01227 ** the third parameter to the sqlite3_set_authorizer() interface.
    01228 ** The second parameter to the callback is an integer
    01229 ** [SQLITE_COPY | action code] that specifies the particular action
    01230 ** to be authorized.  The available action codes are
    01231 ** [SQLITE_COPY | documented separately].  The third through sixth
    01232 ** parameters to the callback are strings that contain additional
    01233 ** details about the action to be authorized.
    01234 **
    01235 ** An authorizer is used when preparing SQL statements from an untrusted
    01236 ** source, to ensure that the SQL statements do not try to access data
    01237 ** that they are not allowed to see, or that they do not try to
    01238 ** execute malicious statements that damage the database.  For
    01239 ** example, an application may allow a user to enter arbitrary
    01240 ** SQL queries for evaluation by a database.  But the application does
    01241 ** not want the user to be able to make arbitrary changes to the
    01242 ** database.  An authorizer could then be put in place while the
    01243 ** user-entered SQL is being prepared that disallows everything
    01244 ** except SELECT statements.
    01245 **
    01246 ** Only a single authorizer can be in place on a database connection
    01247 ** at a time.  Each call to sqlite3_set_authorizer overrides the
    01248 ** previous call.  A NULL authorizer means that no authorization
    01249 ** callback is invoked.  The default authorizer is NULL.
    01250 **
    01251 ** Note that the authorizer callback is invoked only during
    01252 ** [sqlite3_prepare()] or its variants.  Authorization is not
    01253 ** performed during statement evaluation in [sqlite3_step()].
    01254 */
    01255 int sqlite3_set_authorizer(
    01256   sqlite3*,
    01257   int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
    01258   void *pUserData
    01259 );
    01260
    01261 /*
    01262 ** CAPI3REF: Authorizer Return Codes
    01263 **
    01264 ** The [sqlite3_set_authorizer | authorizer callback function] must
    01265 ** return either [SQLITE_OK] or one of these two constants in order
    01266 ** to signal SQLite whether or not the action is permitted.  See the
    01267 ** [sqlite3_set_authorizer | authorizer documentation] for additional
    01268 ** information.
    01269 */
    01270 #define SQLITE_DENY   1   /* Abort the SQL statement with an error */
    01271 #define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */
    01272
    01273 /*
    01274 ** CAPI3REF: Authorizer Action Codes
    01275 **
    01276 ** The [sqlite3_set_authorizer()] interface registers a callback function
    01277 ** that is invoked to authorizer certain SQL statement actions.  The
    01278 ** second parameter to the callback is an integer code that specifies
    01279 ** what action is being authorized.  These are the integer action codes that
    01280 ** the authorizer callback may be passed.
    01281 **
    01282 ** These action code values signify what kind of operation is to be
    01283 ** authorized.  The 3rd and 4th parameters to the authorization callback
    01284 ** function will be parameters or NULL depending on which of these
    01285 ** codes is used as the second parameter.  The 5th parameter to the
    01286 ** authorizer callback is the name of the database ("main", "temp",
    01287 ** etc.) if applicable.  The 6th parameter to the authorizer callback
    01288 ** is the name of the inner-most trigger or view that is responsible for
    01289 ** the access attempt or NULL if this access attempt is directly from
    01290 ** top-level SQL code.
    01291 */
    01292 /******************************************* 3rd ************ 4th ***********/
    01293 #define SQLITE_CREATE_INDEX          1   /* Index Name      Table Name      */
    01294 #define SQLITE_CREATE_TABLE          2   /* Table Name      NULL            */
    01295 #define SQLITE_CREATE_TEMP_INDEX     3   /* Index Name      Table Name      */
    01296 #define SQLITE_CREATE_TEMP_TABLE     4   /* Table Name      NULL            */
    01297 #define SQLITE_CREATE_TEMP_TRIGGER   5   /* Trigger Name    Table Name      */
    01298 #define SQLITE_CREATE_TEMP_VIEW      6   /* View Name       NULL            */
    01299 #define SQLITE_CREATE_TRIGGER        7   /* Trigger Name    Table Name      */
    01300 #define SQLITE_CREATE_VIEW           8   /* View Name       NULL            */
    01301 #define SQLITE_DELETE                9   /* Table Name      NULL            */
    01302 #define SQLITE_DROP_INDEX           10   /* Index Name      Table Name      */
    01303 #define SQLITE_DROP_TABLE           11   /* Table Name      NULL            */
    01304 #define SQLITE_DROP_TEMP_INDEX      12   /* Index Name      Table Name      */
    01305 #define SQLITE_DROP_TEMP_TABLE      13   /* Table Name      NULL            */
    01306 #define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
    01307 #define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
    01308 #define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
    01309 #define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
    01310 #define SQLITE_INSERT               18   /* Table Name      NULL            */
    01311 #define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
    01312 #define SQLITE_READ                 20   /* Table Name      Column Name     */
    01313 #define SQLITE_SELECT               21   /* NULL            NULL            */
    01314 #define SQLITE_TRANSACTION          22   /* NULL            NULL            */
    01315 #define SQLITE_UPDATE               23   /* Table Name      Column Name     */
    01316 #define SQLITE_ATTACH               24   /* Filename        NULL            */
    01317 #define SQLITE_DETACH               25   /* Database Name   NULL            */
    01318 #define SQLITE_ALTER_TABLE          26   /* Database Name   Table Name      */
    01319 #define SQLITE_REINDEX              27   /* Index Name      NULL            */
    01320 #define SQLITE_ANALYZE              28   /* Table Name      NULL            */
    01321 #define SQLITE_CREATE_VTABLE        29   /* Table Name      Module Name     */
    01322 #define SQLITE_DROP_VTABLE          30   /* Table Name      Module Name     */
    01323 #define SQLITE_FUNCTION             31   /* Function Name   NULL            */
    01324 #define SQLITE_COPY                  0   /* No longer used */
    01325
    01326 /*
    01327 ** CAPI3REF: Tracing And Profiling Functions
    01328 **
    01329 ** These routines register callback functions that can be used for
    01330 ** tracing and profiling the execution of SQL statements.
    01331 ** The callback function registered by sqlite3_trace() is invoked
    01332 ** at the first [sqlite3_step()] for the evaluation of an SQL statement.
    01333 ** The callback function registered by sqlite3_profile() is invoked
    01334 ** as each SQL statement finishes and includes
    01335 ** information on how long that statement ran.
    01336 **
    01337 ** The sqlite3_profile() API is currently considered experimental and
    01338 ** is subject to change.
    01339 */
    01340 void *sqlite3_trace(sqlite3*, void(*xTrace)(void*,const char*), void*);
    01341 void *sqlite3_profile(sqlite3*,
    01342    void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
    01343
    01344 /*
    01345 ** CAPI3REF: Query Progress Callbacks
    01346 **
    01347 ** This routine configures a callback function - the progress callback - that
    01348 ** is invoked periodically during long running calls to [sqlite3_exec()],
    01349 ** [sqlite3_step()] and [sqlite3_get_table()].  An example use for this
    01350 ** interface is to keep a GUI updated during a large query.
    01351 **
    01352 ** The progress callback is invoked once for every N virtual machine opcodes,
    01353 ** where N is the second argument to this function. The progress callback
    01354 ** itself is identified by the third argument to this function. The fourth
    01355 ** argument to this function is a void pointer passed to the progress callback
    01356 ** function each time it is invoked.
    01357 **
    01358 ** If a call to [sqlite3_exec()], [sqlite3_step()], or [sqlite3_get_table()]
    01359 ** results in fewer than N opcodes being executed, then the progress
    01360 ** callback is never invoked.
    01361 **
    01362 ** Only a single progress callback function may be registered for each
    01363 ** open database connection.  Every call to sqlite3_progress_handler()
    01364 ** overwrites the results of the previous call.
    01365 ** To remove the progress callback altogether, pass NULL as the third
    01366 ** argument to this function.
    01367 **
    01368 ** If the progress callback returns a result other than 0, then the current
    01369 ** query is immediately terminated and any database changes rolled back.
    01370 ** The containing [sqlite3_exec()], [sqlite3_step()], or
    01371 ** [sqlite3_get_table()] call returns SQLITE_INTERRUPT.   This feature
    01372 ** can be used, for example, to implement the "Cancel" button on a
    01373 ** progress dialog box in a GUI.
    01374 */
    01375 void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
    01376
    01377 /*
    01378 ** CAPI3REF: Opening A New Database Connection
    01379 **
    01380 ** Open the sqlite database file "filename".  The "filename" is UTF-8
    01381 ** encoded for [sqlite3_open()] and [sqlite3_open_v2()] and UTF-16 encoded
    01382 ** in the native byte order for [sqlite3_open16()].
    01383 ** An [sqlite3*] handle is returned in *ppDb, even
    01384 ** if an error occurs. If the database is opened (or created) successfully,
    01385 ** then [SQLITE_OK] is returned. Otherwise an error code is returned. The
    01386 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()]  routines can be used to obtain
    01387 ** an English language description of the error.
    01388 **
    01389 ** The default encoding for the database will be UTF-8 if
    01390 ** [sqlite3_open()] or [sqlite3_open_v2()] is called and
    01391 ** UTF-16 if [sqlite3_open16()] is used.
    01392 **
    01393 ** Whether or not an error occurs when it is opened, resources associated
    01394 ** with the [sqlite3*] handle should be released by passing it to
    01395 ** [sqlite3_close()] when it is no longer required.
    01396 **
    01397 ** The [sqlite3_open_v2()] interface works like [sqlite3_open()] except that
    01398 ** provides two additional parameters for additional control over the
    01399 ** new database connection.  The flags parameter can be one of:
    01400 **
    01401 ** <ol>
    01402 ** <li>  [SQLITE_OPEN_READONLY]
    01403 ** <li>  [SQLITE_OPEN_READWRITE]
    01404 ** <li>  [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]
    01405 ** </ol>
    01406 **
    01407 ** The first value opens the database read-only.  If the database does
    01408 ** not previously exist, an error is returned.  The second option opens
    01409 ** the database for reading and writing if possible, or reading only if
    01410 ** if the file is write protected.  In either case the database must already
    01411 ** exist or an error is returned.  The third option opens the database
    01412 ** for reading and writing and creates it if it does not already exist.
    01413 ** The third options is behavior that is always used for [sqlite3_open()]
    01414 ** and [sqlite3_open16()].
    01415 **
    01416 ** If the filename is ":memory:", then an private
    01417 ** in-memory database is created for the connection.  This in-memory
    01418 ** database will vanish when the database connection is closed.  Future
    01419 ** version of SQLite might make use of additional special filenames
    01420 ** that begin with the ":" character.  It is recommended that
    01421 ** when a database filename really does begin with
    01422 ** ":" that you prefix the filename with a pathname like "./" to
    01423 ** avoid ambiguity.
    01424 **
    01425 ** If the filename is an empty string, then a private temporary
    01426 ** on-disk database will be created.  This private database will be
    01427 ** automatically deleted as soon as the database connection is closed.
    01428 **
    01429 ** The fourth parameter to sqlite3_open_v2() is the name of the
    01430 ** [sqlite3_vfs] object that defines the operating system
    01431 ** interface that the new database connection should use.  If the
    01432 ** fourth parameter is a NULL pointer then the default [sqlite3_vfs]
    01433 ** object is used.
    01434 **
    01435 ** <b>Note to windows users:</b>  The encoding used for the filename argument
    01436 ** of [sqlite3_open()] and [sqlite3_open_v2()] must be UTF-8, not whatever
    01437 ** codepage is currently defined.  Filenames containing international
    01438 ** characters must be converted to UTF-8 prior to passing them into
    01439 ** [sqlite3_open()] or [sqlite3_open_v2()].
    01440 */
    01441 int sqlite3_open(
    01442   const char *filename,   /* Database filename (UTF-8) */
    01443   sqlite3 **ppDb          /* OUT: SQLite db handle */
    01444 );
    01445 int sqlite3_open16(
    01446   const void *filename,   /* Database filename (UTF-16) */
    01447   sqlite3 **ppDb          /* OUT: SQLite db handle */
    01448 );
    01449 int sqlite3_open_v2(
    01450   const char *filename,   /* Database filename (UTF-8) */
    01451   sqlite3 **ppDb,         /* OUT: SQLite db handle */
    01452   int flags,              /* Flags */
    01453   const char *zVfs        /* Name of VFS module to use */
    01454 );
    01455
    01456 /*
    01457 ** CAPI3REF: Error Codes And Messages
    01458 **
    01459 ** The sqlite3_errcode() interface returns the numeric
    01460 ** [SQLITE_OK | result code] or [SQLITE_IOERR_READ | extended result code]
    01461 ** for the most recent failed sqlite3_* API call associated
    01462 ** with [sqlite3] handle 'db'.  If a prior API call failed but the
    01463 ** most recent API call succeeded, the return value from sqlite3_errcode()
    01464 ** is undefined.
    01465 **
    01466 ** The sqlite3_errmsg() and sqlite3_errmsg16() return English-langauge
    01467 ** text that describes the error, as either UTF8 or UTF16 respectively.
    01468 ** Memory to hold the error message string is managed internally.  The
    01469 ** string may be overwritten or deallocated by subsequent calls to SQLite
    01470 ** interface functions.
    01471 **
    01472 ** Calls to many sqlite3_* functions set the error code and string returned
    01473 ** by [sqlite3_errcode()], [sqlite3_errmsg()], and [sqlite3_errmsg16()]
    01474 ** (overwriting the previous values). Note that calls to [sqlite3_errcode()],
    01475 ** [sqlite3_errmsg()], and [sqlite3_errmsg16()] themselves do not affect the
    01476 ** results of future invocations.  Calls to API routines that do not return
    01477 ** an error code (example: [sqlite3_data_count()]) do not
    01478 ** change the error code returned by this routine.  Interfaces that are
    01479 ** not associated with a specific database connection (examples:
    01480 ** [sqlite3_mprintf()] or [sqlite3_enable_shared_cache()] do not change
    01481 ** the return code.
    01482 **
    01483 ** Assuming no other intervening sqlite3_* API calls are made, the error
    01484 ** code returned by this function is associated with the same error as
    01485 ** the strings returned by [sqlite3_errmsg()] and [sqlite3_errmsg16()].
    01486 */
    01487 int sqlite3_errcode(sqlite3 *db);
    01488 const char *sqlite3_errmsg(sqlite3*);
    01489 const void *sqlite3_errmsg16(sqlite3*);
    01490
    01491 /*
    01492 ** CAPI3REF: SQL Statement Object
    01493 **
    01494 ** Instance of this object represent single SQL statements.  This
    01495 ** is variously known as a "prepared statement" or a
    01496 ** "compiled SQL statement" or simply as a "statement".
    01497 **
    01498 ** The life of a statement object goes something like this:
    01499 **
    01500 ** <ol>
    01501 ** <li> Create the object using [sqlite3_prepare_v2()] or a related
    01502 **      function.
    01503 ** <li> Bind values to host parameters using
    01504 **      [sqlite3_bind_blob | sqlite3_bind_* interfaces].
    01505 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
    01506 ** <li> Reset the statement using [sqlite3_reset()] then go back
    01507 **      to step 2.  Do this zero or more times.
    01508 ** <li> Destroy the object using [sqlite3_finalize()].
    01509 ** </ol>
    01510 **
    01511 ** Refer to documentation on individual methods above for additional
    01512 ** information.
    01513 */
    01514 typedef struct sqlite3_stmt sqlite3_stmt;
    01515
    01516 /*
    01517 ** CAPI3REF: Compiling An SQL Statement
    01518 **
    01519 ** To execute an SQL query, it must first be compiled into a byte-code
    01520 ** program using one of these routines.
    01521 **
    01522 ** The first argument "db" is an [sqlite3 | SQLite database handle]
    01523 ** obtained from a prior call to [sqlite3_open()], [sqlite3_open_v2()]
    01524 ** or [sqlite3_open16()].
    01525 ** The second argument "zSql" is the statement to be compiled, encoded
    01526 ** as either UTF-8 or UTF-16.  The sqlite3_prepare() and sqlite3_prepare_v2()
    01527 ** interfaces uses UTF-8 and sqlite3_prepare16() and sqlite3_prepare16_v2()
    01528 ** use UTF-16.
    01529 **
    01530 ** If the nByte argument is less
    01531 ** than zero, then zSql is read up to the first zero terminator.  If
    01532 ** nByte is non-negative, then it is the maximum number of
    01533 ** bytes read from zSql.  When nByte is non-negative, the
    01534 ** zSql string ends at either the first '\000' character or
    01535 ** until the nByte-th byte, whichever comes first.
    01536 **
    01537 ** *pzTail is made to point to the first byte past the end of the first
    01538 ** SQL statement in zSql.  This routine only compiles the first statement
    01539 ** in zSql, so *pzTail is left pointing to what remains uncompiled.
    01540 **
    01541 ** *ppStmt is left pointing to a compiled
    01542 ** [sqlite3_stmt | SQL statement structure] that can be
    01543 ** executed using [sqlite3_step()].  Or if there is an error, *ppStmt may be
    01544 ** set to NULL.  If the input text contained no SQL (if the input is and
    01545 ** empty string or a comment) then *ppStmt is set to NULL.  The calling
    01546 ** procedure is responsible for deleting the compiled SQL statement
    01547 ** using [sqlite3_finalize()] after it has finished with it.
    01548 **
    01549 ** On success, [SQLITE_OK] is returned.  Otherwise an
    01550 ** [SQLITE_ERROR | error code] is returned.
    01551 **
    01552 ** The sqlite3_prepare_v2() and sqlite3_prepare16_v2() interfaces are
    01553 ** recommended for all new programs. The two older interfaces are retained
    01554 ** for backwards compatibility, but their use is discouraged.
    01555 ** In the "v2" interfaces, the prepared statement
    01556 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
    01557 ** original SQL text. This causes the [sqlite3_step()] interface to
    01558 ** behave a differently in two ways:
    01559 **
    01560 ** <ol>
    01561 ** <li>
    01562 ** If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
    01563 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
    01564 ** statement and try to run it again.  If the schema has changed in a way
    01565 ** that makes the statement no longer valid, [sqlite3_step()] will still
    01566 ** return [SQLITE_SCHEMA].  But unlike the legacy behavior, [SQLITE_SCHEMA] is
    01567 ** now a fatal error.  Calling [sqlite3_prepare_v2()] again will not make the
    01568 ** error go away.  Note: use [sqlite3_errmsg()] to find the text of the parsing
    01569 ** error that results in an [SQLITE_SCHEMA] return.
    01570 ** </li>
    01571 **
    01572 ** <li>
    01573 ** When an error occurs,
    01574 ** [sqlite3_step()] will return one of the detailed
    01575 ** [SQLITE_ERROR | result codes] or
    01576 ** [SQLITE_IOERR_READ | extended result codes] such as directly.
    01577 ** The legacy behavior was that [sqlite3_step()] would only return a generic
    01578 ** [SQLITE_ERROR] result code and you would have to make a second call to
    01579 ** [sqlite3_reset()] in order to find the underlying cause of the problem.
    01580 ** With the "v2" prepare interfaces, the underlying reason for the error is
    01581 ** returned immediately.
    01582 ** </li>
    01583 ** </ol>
    01584 */
    01585 int sqlite3_prepare(
    01586   sqlite3 *db,            /* Database handle */
    01587   const char *zSql,       /* SQL statement, UTF-8 encoded */
    01588   int nByte,              /* Maximum length of zSql in bytes. */
    01589   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    01590   const char **pzTail     /* OUT: Pointer to unused portion of zSql */
    01591 );
    01592 int sqlite3_prepare_v2(
    01593   sqlite3 *db,            /* Database handle */
    01594   const char *zSql,       /* SQL statement, UTF-8 encoded */
    01595   int nByte,              /* Maximum length of zSql in bytes. */
    01596   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    01597   const char **pzTail     /* OUT: Pointer to unused portion of zSql */
    01598 );
    01599 int sqlite3_prepare16(
    01600   sqlite3 *db,            /* Database handle */
    01601   const void *zSql,       /* SQL statement, UTF-16 encoded */
    01602   int nByte,              /* Maximum length of zSql in bytes. */
    01603   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    01604   const void **pzTail     /* OUT: Pointer to unused portion of zSql */
    01605 );
    01606 int sqlite3_prepare16_v2(
    01607   sqlite3 *db,            /* Database handle */
    01608   const void *zSql,       /* SQL statement, UTF-16 encoded */
    01609   int nByte,              /* Maximum length of zSql in bytes. */
    01610   sqlite3_stmt **ppStmt,  /* OUT: Statement handle */
    01611   const void **pzTail     /* OUT: Pointer to unused portion of zSql */
    01612 );
    01613
    01614 /*
    01615 ** CAPI3REF:  Dynamically Typed Value Object
    01616 **
    01617 ** SQLite uses dynamic typing for the values it stores.  Values can
    01618 ** be integers, floating point values, strings, BLOBs, or NULL.  When
    01619 ** passing around values internally, each value is represented as
    01620 ** an instance of the sqlite3_value object.
    01621 */
    01622 typedef struct Mem sqlite3_value;
    01623
    01624 /*
    01625 ** CAPI3REF:  SQL Function Context Object
    01626 **
    01627 ** The context in which an SQL function executes is stored in an
    01628 ** sqlite3_context object.  A pointer to such an object is the
    01629 ** first parameter to user-defined SQL functions.
    01630 */
    01631 typedef struct sqlite3_context sqlite3_context;
    01632
    01633 /*
    01634 ** CAPI3REF:  Binding Values To Prepared Statements
    01635 **
    01636 ** In the SQL strings input to [sqlite3_prepare_v2()] and its variants,
    01637 ** one or more literals can be replace by a parameter in one of these
    01638 ** forms:
    01639 **
    01640 ** <ul>
    01641 ** <li>  ?
    01642 ** <li>  ?NNN
    01643 ** <li>  :AAA
    01644 ** <li>  @AAA
    01645 ** <li>  $VVV
    01646 ** </ul>
    01647 **
    01648 ** In the parameter forms shown above NNN is an integer literal,
    01649 ** AAA is an alphanumeric identifier and VVV is a variable name according
    01650 ** to the syntax rules of the TCL programming language.
    01651 ** The values of these parameters (also called "host parameter names")
    01652 ** can be set using the sqlite3_bind_*() routines defined here.
    01653 **
    01654 ** The first argument to the sqlite3_bind_*() routines always is a pointer
    01655 ** to the [sqlite3_stmt] object returned from [sqlite3_prepare_v2()] or
    01656 ** its variants.  The second
    01657 ** argument is the index of the parameter to be set.  The first parameter has
    01658 ** an index of 1. When the same named parameter is used more than once, second
    01659 ** and subsequent
    01660 ** occurrences have the same index as the first occurrence.  The index for
    01661 ** named parameters can be looked up using the
    01662 ** [sqlite3_bind_parameter_name()] API if desired.  The index for "?NNN"
    01663 ** parametes is the value of NNN.
    01664 ** The NNN value must be between 1 and the compile-time
    01665 ** parameter SQLITE_MAX_VARIABLE_NUMBER (default value: 999).
    01666 ** See <a href="limits.html">limits.html</a> for additional information.
    01667 **
    01668 ** The third argument is the value to bind to the parameter.
    01669 **
    01670 ** In those
    01671 ** routines that have a fourth argument, its value is the number of bytes
    01672 ** in the parameter.  To be clear: the value is the number of bytes in the
    01673 ** string, not the number of characters.  The number
    01674 ** of bytes does not include the zero-terminator at the end of strings.
    01675 ** If the fourth parameter is negative, the length of the string is
    01676 ** number of bytes up to the first zero terminator.
    01677 **
    01678 ** The fifth argument to sqlite3_bind_blob(), sqlite3_bind_text(), and
    01679 ** sqlite3_bind_text16() is a destructor used to dispose of the BLOB or
    01680 ** text after SQLite has finished with it.  If the fifth argument is the
    01681 ** special value [SQLITE_STATIC], then the library assumes that the information
    01682 ** is in static, unmanaged space and does not need to be freed.  If the
    01683 ** fifth argument has the value [SQLITE_TRANSIENT], then SQLite makes its
    01684 ** own private copy of the data immediately, before the sqlite3_bind_*()
    01685 ** routine returns.
    01686 **
    01687 ** The sqlite3_bind_zeroblob() routine binds a BLOB of length n that
    01688 ** is filled with zeros.  A zeroblob uses a fixed amount of memory
    01689 ** (just an integer to hold it size) while it is being processed.
    01690 ** Zeroblobs are intended to serve as place-holders for BLOBs whose
    01691 ** content is later written using
    01692 ** [sqlite3_blob_open | increment BLOB I/O] routines.
    01693 **
    01694 ** The sqlite3_bind_*() routines must be called after
    01695 ** [sqlite3_prepare_v2()] (and its variants) or [sqlite3_reset()] and
    01696 ** before [sqlite3_step()].
    01697 ** Bindings are not cleared by the [sqlite3_reset()] routine.
    01698 ** Unbound parameters are interpreted as NULL.
    01699 **
    01700 ** These routines return [SQLITE_OK] on success or an error code if
    01701 ** anything goes wrong.  [SQLITE_RANGE] is returned if the parameter
    01702 ** index is out of range.  [SQLITE_NOMEM] is returned if malloc fails.
    01703 ** [SQLITE_MISUSE] is returned if these routines are called on a virtual
    01704 ** machine that is the wrong state or which has already been finalized.
    01705 */
    01706 int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
    01707 int sqlite3_bind_double(sqlite3_stmt*, int, double);
    01708 int sqlite3_bind_int(sqlite3_stmt*, int, int);
    01709 int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
    01710 int sqlite3_bind_null(sqlite3_stmt*, int);
    01711 int sqlite3_bind_text(sqlite3_stmt*, int, const char*, int n, void(*)(void*));
    01712 int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
    01713 int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
    01714 int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
    01715
    01716 /*
    01717 ** CAPI3REF: Number Of Host Parameters
    01718 **
    01719 ** Return the largest host parameter index in the precompiled statement given
    01720 ** as the argument.  When the host parameters are of the forms like ":AAA"
    01721 ** or "?", then they are assigned sequential increasing numbers beginning
    01722 ** with one, so the value returned is the number of parameters.  However
    01723 ** if the same host parameter name is used multiple times, each occurrance
    01724 ** is given the same number, so the value returned in that case is the number
    01725 ** of unique host parameter names.  If host parameters of the form "?NNN"
    01726 ** are used (where NNN is an integer) then there might be gaps in the
    01727 ** numbering and the value returned by this interface is the index of the
    01728 ** host parameter with the largest index value.
    01729 **
    01730 ** The prepared statement must not be [sqlite3_finalize | finalized]
    01731 ** prior to this routine returnning.  Otherwise the results are undefined
    01732 ** and probably undesirable.
    01733 */
    01734 int sqlite3_bind_parameter_count(sqlite3_stmt*);
    01735
    01736 /*
    01737 ** CAPI3REF: Name Of A Host Parameter
    01738 **
    01739 ** This routine returns a pointer to the name of the n-th parameter in a
    01740 ** [sqlite3_stmt | prepared statement].
    01741 ** Host parameters of the form ":AAA" or "@AAA" or "$VVV" have a name
    01742 ** which is the string ":AAA" or "@AAA" or "$VVV".
    01743 ** In other words, the initial ":" or "$" or "@"
    01744 ** is included as part of the name.
    01745 ** Parameters of the form "?" or "?NNN" have no name.
    01746 **
    01747 ** The first bound parameter has an index of 1, not 0.
    01748 **
    01749 ** If the value n is out of range or if the n-th parameter is nameless,
    01750 ** then NULL is returned.  The returned string is always in the
    01751 ** UTF-8 encoding even if the named parameter was originally specified
    01752 ** as UTF-16 in [sqlite3_prepare16()] or [sqlite3_prepare16_v2()].
    01753 */
    01754 const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
    01755
    01756 /*
    01757 ** CAPI3REF: Index Of A Parameter With A Given Name
    01758 **
    01759 ** This routine returns the index of a host parameter with the given name.
    01760 ** The name must match exactly.  If no parameter with the given name is
    01761 ** found, return 0.  Parameter names must be UTF8.
    01762 */
    01763 int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
    01764
    01765 /*
    01766 ** CAPI3REF: Reset All Bindings On A Prepared Statement
    01767 **
    01768 ** Contrary to the intuition of many, [sqlite3_reset()] does not
    01769 ** reset the [sqlite3_bind_blob | bindings] on a
    01770 ** [sqlite3_stmt | prepared statement].  Use this routine to
    01771 ** reset all host parameters to NULL.
    01772 */
    01773 int sqlite3_clear_bindings(sqlite3_stmt*);
    01774
    01775 /*
    01776 ** CAPI3REF: Number Of Columns In A Result Set
    01777 **
    01778 ** Return the number of columns in the result set returned by the
    01779 ** [sqlite3_stmt | compiled SQL statement]. This routine returns 0
    01780 ** if pStmt is an SQL statement that does not return data (for
    01781 ** example an UPDATE).
    01782 */
    01783 int sqlite3_column_count(sqlite3_stmt *pStmt);
    01784
    01785 /*
    01786 ** CAPI3REF: Column Names In A Result Set
    01787 **
    01788 ** These routines return the name assigned to a particular column
    01789 ** in the result set of a SELECT statement.  The sqlite3_column_name()
    01790 ** interface returns a pointer to a UTF8 string and sqlite3_column_name16()
    01791 ** returns a pointer to a UTF16 string.  The first parameter is the
    01792 ** [sqlite3_stmt | prepared statement] that implements the SELECT statement.
    01793 ** The second parameter is the column number.  The left-most column is
    01794 ** number 0.
    01795 **
    01796 ** The returned string pointer is valid until either the
    01797 ** [sqlite3_stmt | prepared statement] is destroyed by [sqlite3_finalize()]
    01798 ** or until the next call sqlite3_column_name() or sqlite3_column_name16()
    01799 ** on the same column.
    01800 **
    01801 ** If sqlite3_malloc() fails during the processing of either routine
    01802 ** (for example during a conversion from UTF-8 to UTF-16) then a
    01803 ** NULL pointer is returned.
    01804 */
    01805 const char *sqlite3_column_name(sqlite3_stmt*, int N);
    01806 const void *sqlite3_column_name16(sqlite3_stmt*, int N);
    01807
    01808 /*
    01809 ** CAPI3REF: Source Of Data In A Query Result
    01810 **
    01811 ** These routines provide a means to determine what column of what
    01812 ** table in which database a result of a SELECT statement comes from.
    01813 ** The name of the database or table or column can be returned as
    01814 ** either a UTF8 or UTF16 string.  The _database_ routines return
    01815 ** the database name, the _table_ routines return the table name, and
    01816 ** the origin_ routines return the column name.
    01817 ** The returned string is valid until
    01818 ** the [sqlite3_stmt | prepared statement] is destroyed using
    01819 ** [sqlite3_finalize()] or until the same information is requested
    01820 ** again in a different encoding.
    01821 **
    01822 ** The names returned are the original un-aliased names of the
    01823 ** database, table, and column.
    01824 **
    01825 ** The first argument to the following calls is a
    01826 ** [sqlite3_stmt | compiled SQL statement].
    01827 ** These functions return information about the Nth column returned by
    01828 ** the statement, where N is the second function argument.
    01829 **
    01830 ** If the Nth column returned by the statement is an expression
    01831 ** or subquery and is not a column value, then all of these functions
    01832 ** return NULL. Otherwise, they return the
    01833 ** name of the attached database, table and column that query result
    01834 ** column was extracted from.
    01835 **
    01836 ** As with all other SQLite APIs, those postfixed with "16" return UTF-16
    01837 ** encoded strings, the other functions return UTF-8.
    01838 **
    01839 ** These APIs are only available if the library was compiled with the
    01840 ** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
    01841 **
    01842 ** If two or more threads call one or more of these routines against the same
    01843 ** prepared statement and column at the same time then the results are
    01844 ** undefined.
    01845 */
    01846 const char *sqlite3_column_database_name(sqlite3_stmt*,int);
    01847 const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
    01848 const char *sqlite3_column_table_name(sqlite3_stmt*,int);
    01849 const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
    01850 const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
    01851 const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
    01852
    01853 /*
    01854 ** CAPI3REF: Declared Datatype Of A Query Result
    01855 **
    01856 ** The first parameter is a [sqlite3_stmt | compiled SQL statement].
    01857 ** If this statement is a SELECT statement and the Nth column of the
    01858 ** returned result set  of that SELECT is a table column (not an
    01859 ** expression or subquery) then the declared type of the table
    01860 ** column is returned. If the Nth column of the result set is an
    01861 ** expression or subquery, then a NULL pointer is returned.
    01862 ** The returned string is always UTF-8 encoded. For example, in
    01863 ** the database schema:
    01864 **
    01865 ** CREATE TABLE t1(c1 VARIANT);
    01866 **
    01867 ** And the following statement compiled:
    01868 **
    01869 ** SELECT c1 + 1, c1 FROM t1;
    01870 **
    01871 ** Then this routine would return the string "VARIANT" for the second
    01872 ** result column (i==1), and a NULL pointer for the first result column
    01873 ** (i==0).
    01874 **
    01875 ** SQLite uses dynamic run-time typing.  So just because a column
    01876 ** is declared to contain a particular type does not mean that the
    01877 ** data stored in that column is of the declared type.  SQLite is
    01878 ** strongly typed, but the typing is dynamic not static.  Type
    01879 ** is associated with individual values, not with the containers
    01880 ** used to hold those values.
    01881 */
    01882 const char *sqlite3_column_decltype(sqlite3_stmt *, int i);
    01883 const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
    01884
    01885 /*
    01886 ** CAPI3REF:  Evaluate An SQL Statement
    01887 **
    01888 ** After an [sqlite3_stmt | SQL statement] has been prepared with a call
    01889 ** to either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] or to one of
    01890 ** the legacy interfaces [sqlite3_prepare()] or [sqlite3_prepare16()],
    01891 ** then this function must be called one or more times to evaluate the
    01892 ** statement.
    01893 **
    01894 ** The details of the behavior of this sqlite3_step() interface depend
    01895 ** on whether the statement was prepared using the newer "v2" interface
    01896 ** [sqlite3_prepare_v2()] and [sqlite3_prepare16_v2()] or the older legacy
    01897 ** interface [sqlite3_prepare()] and [sqlite3_prepare16()].  The use of the
    01898 ** new "v2" interface is recommended for new applications but the legacy
    01899 ** interface will continue to be supported.
    01900 **
    01901 ** In the lagacy interface, the return value will be either [SQLITE_BUSY],
    01902 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
    01903 ** With the "v2" interface, any of the other [SQLITE_OK | result code]
    01904 ** or [SQLITE_IOERR_READ | extended result code] might be returned as
    01905 ** well.
    01906 **
    01907 ** [SQLITE_BUSY] means that the database engine was unable to acquire the
    01908 ** database locks it needs to do its job.  If the statement is a COMMIT
    01909 ** or occurs outside of an explicit transaction, then you can retry the
    01910 ** statement.  If the statement is not a COMMIT and occurs within a
    01911 ** explicit transaction then you should rollback the transaction before
    01912 ** continuing.
    01913 **
    01914 ** [SQLITE_DONE] means that the statement has finished executing
    01915 ** successfully.  sqlite3_step() should not be called again on this virtual
    01916 ** machine without first calling [sqlite3_reset()] to reset the virtual
    01917 ** machine back to its initial state.
    01918 **
    01919 ** If the SQL statement being executed returns any data, then
    01920 ** [SQLITE_ROW] is returned each time a new row of data is ready
    01921 ** for processing by the caller. The values may be accessed using
    01922 ** the [sqlite3_column_int | column access functions].
    01923 ** sqlite3_step() is called again to retrieve the next row of data.
    01924 **
    01925 ** [SQLITE_ERROR] means that a run-time error (such as a constraint
    01926 ** violation) has occurred.  sqlite3_step() should not be called again on
    01927 ** the VM. More information may be found by calling [sqlite3_errmsg()].
    01928 ** With the legacy interface, a more specific error code (example:
    01929 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
    01930 ** can be obtained by calling [sqlite3_reset()] on the
    01931 ** [sqlite3_stmt | prepared statement].  In the "v2" interface,
    01932 ** the more specific error code is returned directly by sqlite3_step().
    01933 **
    01934 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
    01935 ** Perhaps it was called on a [sqlite3_stmt | prepared statement] that has
    01936 ** already been [sqlite3_finalize | finalized] or on one that had
    01937 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE].  Or it could
    01938 ** be the case that the same database connection is being used by two or
    01939 ** more threads at the same moment in time.
    01940 **
    01941 ** <b>Goofy Interface Alert:</b>
    01942 ** In the legacy interface,
    01943 ** the sqlite3_step() API always returns a generic error code,
    01944 ** [SQLITE_ERROR], following any error other than [SQLITE_BUSY]
    01945 ** and [SQLITE_MISUSE].  You must call [sqlite3_reset()] or
    01946 ** [sqlite3_finalize()] in order to find one of the specific
    01947 ** [SQLITE_ERROR | result codes] that better describes the error.
    01948 ** We admit that this is a goofy design.  The problem has been fixed
    01949 ** with the "v2" interface.  If you prepare all of your SQL statements
    01950 ** using either [sqlite3_prepare_v2()] or [sqlite3_prepare16_v2()] instead
    01951 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()], then the
    01952 ** more specific [SQLITE_ERROR | result codes] are returned directly
    01953 ** by sqlite3_step().  The use of the "v2" interface is recommended.
    01954 */
    01955 int sqlite3_step(sqlite3_stmt*);
    01956
    01957 /*
    01958 ** CAPI3REF:
    01959 **
    01960 ** Return the number of values in the current row of the result set.
    01961 **
    01962 ** After a call to [sqlite3_step()] that returns [SQLITE_ROW], this routine
    01963 ** will return the same value as the [sqlite3_column_count()] function.
    01964 ** After [sqlite3_step()] has returned an [SQLITE_DONE], [SQLITE_BUSY], or
    01965 ** a [SQLITE_ERROR | error code], or before [sqlite3_step()] has been
    01966 ** called on the [sqlite3_stmt | prepared statement] for the first time,
    01967 ** this routine returns zero.
    01968 */
    01969 int sqlite3_data_count(sqlite3_stmt *pStmt);
    01970
    01971 /*
    01972 ** CAPI3REF: Fundamental Datatypes
    01973 **
    01974 ** Every value in SQLite has one of five fundamental datatypes:
    01975 **
    01976 ** <ul>
    01977 ** <li> 64-bit signed integer
    01978 ** <li> 64-bit IEEE floating point number
    01979 ** <li> string
    01980 ** <li> BLOB
    01981 ** <li> NULL
    01982 ** </ul>
    01983 **
    01984 ** These constants are codes for each of those types.
    01985 **
    01986 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
    01987 ** for a completely different meaning.  Software that links against both
    01988 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT not
    01989 ** SQLITE_TEXT.
    01990 */
    01991 #define SQLITE_INTEGER  1
    01992 #define SQLITE_FLOAT    2
    01993 #define SQLITE_BLOB     4
    01994 #define SQLITE_NULL     5
    01995 #ifdef SQLITE_TEXT
    01996 # undef SQLITE_TEXT
    01997 #else
    01998 # define SQLITE_TEXT     3
    01999 #endif
    02000 #define SQLITE3_TEXT     3
    02001
    02002 /*
    02003 ** CAPI3REF: Results Values From A Query
    02004 **
    02005 ** These routines return information about
    02006 ** a single column of the current result row of a query.  In every
    02007 ** case the first argument is a pointer to the
    02008 ** [sqlite3_stmt | SQL statement] that is being
    02009 ** evaluated (the [sqlite3_stmt*] that was returned from
    02010 ** [sqlite3_prepare_v2()] or one of its variants) and
    02011 ** the second argument is the index of the column for which information
    02012 ** should be returned.  The left-most column of the result set
    02013 ** has an index of 0.
    02014 **
    02015 ** If the SQL statement is not currently point to a valid row, or if the
    02016 ** the column index is out of range, the result is undefined.
    02017 ** These routines may only be called when the most recent call to
    02018 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
    02019 ** [sqlite3_reset()] nor [sqlite3_finalize()] has been call subsequently.
    02020 ** If any of these routines are called after [sqlite3_reset()] or
    02021 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
    02022 ** something other than [SQLITE_ROW], the results are undefined.
    02023 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
    02024 ** are called from a different thread while any of these routines
    02025 ** are pending, then the results are undefined.
    02026 **
    02027 ** The sqlite3_column_type() routine returns
    02028 ** [SQLITE_INTEGER | datatype code] for the initial data type
    02029 ** of the result column.  The returned value is one of [SQLITE_INTEGER],
    02030 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].  The value
    02031 ** returned by sqlite3_column_type() is only meaningful if no type
    02032 ** conversions have occurred as described below.  After a type conversion,
    02033 ** the value returned by sqlite3_column_type() is undefined.  Future
    02034 ** versions of SQLite may change the behavior of sqlite3_column_type()
    02035 ** following a type conversion.
    02036 **
    02037 ** If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
    02038 ** routine returns the number of bytes in that BLOB or string.
    02039 ** If the result is a UTF-16 string, then sqlite3_column_bytes() converts
    02040 ** the string to UTF-8 and then returns the number of bytes.
    02041 ** If the result is a numeric value then sqlite3_column_bytes() uses
    02042 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
    02043 ** the number of bytes in that string.
    02044 ** The value returned does not include the zero terminator at the end
    02045 ** of the string.  For clarity: the value returned is the number of
    02046 ** bytes in the string, not the number of characters.
    02047 **
    02048 ** The sqlite3_column_bytes16() routine is similar to sqlite3_column_bytes()
    02049 ** but leaves the result in UTF-16 instead of UTF-8.
    02050 ** The zero terminator is not included in this count.
    02051 **
    02052 ** These routines attempt to convert the value where appropriate.  For
    02053 ** example, if the internal representation is FLOAT and a text result
    02054 ** is requested, [sqlite3_snprintf()] is used internally to do the conversion
    02055 ** automatically.  The following table details the conversions that
    02056 ** are applied:
    02057 **
    02058 ** <blockquote>
    02059 ** <table border="1">
    02060 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th>  Conversion
    02061 **
    02062 ** <tr><td>  NULL    <td> INTEGER   <td> Result is 0
    02063 ** <tr><td>  NULL    <td>  FLOAT    <td> Result is 0.0
    02064 ** <tr><td>  NULL    <td>   TEXT    <td> Result is NULL pointer
    02065 ** <tr><td>  NULL    <td>   BLOB    <td> Result is NULL pointer
    02066 ** <tr><td> INTEGER  <td>  FLOAT    <td> Convert from integer to float
    02067 ** <tr><td> INTEGER  <td>   TEXT    <td> ASCII rendering of the integer
    02068 ** <tr><td> INTEGER  <td>   BLOB    <td> Same as for INTEGER->TEXT
    02069 ** <tr><td>  FLOAT   <td> INTEGER   <td> Convert from float to integer
    02070 ** <tr><td>  FLOAT   <td>   TEXT    <td> ASCII rendering of the float
    02071 ** <tr><td>  FLOAT   <td>   BLOB    <td> Same as FLOAT->TEXT
    02072 ** <tr><td>  TEXT    <td> INTEGER   <td> Use atoi()
    02073 ** <tr><td>  TEXT    <td>  FLOAT    <td> Use atof()
    02074 ** <tr><td>  TEXT    <td>   BLOB    <td> No change
    02075 ** <tr><td>  BLOB    <td> INTEGER   <td> Convert to TEXT then use atoi()
    02076 ** <tr><td>  BLOB    <td>  FLOAT    <td> Convert to TEXT then use atof()
    02077 ** <tr><td>  BLOB    <td>   TEXT    <td> Add a zero terminator if needed
    02078 ** </table>
    02079 ** </blockquote>
    02080 **
    02081 ** The table above makes reference to standard C library functions atoi()
    02082 ** and atof().  SQLite does not really use these functions.  It has its
    02083 ** on equavalent internal routines.  The atoi() and atof() names are
    02084 ** used in the table for brevity and because they are familiar to most
    02085 ** C programmers.
    02086 **
    02087 ** Note that when type conversions occur, pointers returned by prior
    02088 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
    02089 ** sqlite3_column_text16() may be invalidated.
    02090 ** Type conversions and pointer invalidations might occur
    02091 ** in the following cases:
    02092 **
    02093 ** <ul>
    02094 ** <li><p>  The initial content is a BLOB and sqlite3_column_text()
    02095 **          or sqlite3_column_text16() is called.  A zero-terminator might
    02096 **          need to be added to the string.</p></li>
    02097 **
    02098 ** <li><p>  The initial content is UTF-8 text and sqlite3_column_bytes16() or
    02099 **          sqlite3_column_text16() is called.  The content must be converted
    02100 **          to UTF-16.</p></li>
    02101 **
    02102 ** <li><p>  The initial content is UTF-16 text and sqlite3_column_bytes() or
    02103 **          sqlite3_column_text() is called.  The content must be converted
    02104 **          to UTF-8.</p></li>
    02105 ** </ul>
    02106 **
    02107 ** Conversions between UTF-16be and UTF-16le are always done in place and do
    02108 ** not invalidate a prior pointer, though of course the content of the buffer
    02109 ** that the prior pointer points to will have been modified.  Other kinds
    02110 ** of conversion are done in place when it is possible, but sometime it is
    02111 ** not possible and in those cases prior pointers are invalidated.
    02112 **
    02113 ** The safest and easiest to remember policy is to invoke these routines
    02114 ** in one of the following ways:
    02115 **
    02116 **  <ul>
    02117 **  <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
    02118 **  <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
    02119 **  <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
    02120 **  </ul>
    02121 **
    02122 ** In other words, you should call sqlite3_column_text(), sqlite3_column_blob(),
    02123 ** or sqlite3_column_text16() first to force the result into the desired
    02124 ** format, then invoke sqlite3_column_bytes() or sqlite3_column_bytes16() to
    02125 ** find the size of the result.  Do not mix call to sqlite3_column_text() or
    02126 ** sqlite3_column_blob() with calls to sqlite3_column_bytes16().  And do not
    02127 ** mix calls to sqlite3_column_text16() with calls to sqlite3_column_bytes().
    02128 **
    02129 ** The pointers returned are valid until a type conversion occurs as
    02130 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
    02131 ** [sqlite3_finalize()] is called.  The memory space used to hold strings
    02132 ** and blobs is freed automatically.  Do <b>not</b> pass the pointers returned
    02133 ** [sqlite3_column_blob()], [sqlite_column_text()], etc. into
    02134 ** [sqlite3_free()].
    02135 **
    02136 ** If a memory allocation error occurs during the evaluation of any
    02137 ** of these routines, a default value is returned.  The default value
    02138 ** is either the integer 0, the floating point number 0.0, or a NULL
    02139 ** pointer.  Subsequent calls to [sqlite3_errcode()] will return
    02140 ** [SQLITE_NOMEM].
    02141 */
    02142 const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
    02143 int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
    02144 int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
    02145 double sqlite3_column_double(sqlite3_stmt*, int iCol);
    02146 int sqlite3_column_int(sqlite3_stmt*, int iCol);
    02147 sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
    02148 const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
    02149 const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
    02150 int sqlite3_column_type(sqlite3_stmt*, int iCol);
    02151 sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
    02152
    02153 /*
    02154 ** CAPI3REF: Destroy A Prepared Statement Object
    02155 **
    02156 ** The sqlite3_finalize() function is called to delete a
    02157 ** [sqlite3_stmt | compiled SQL statement]. If the statement was
    02158 ** executed successfully, or not executed at all, then SQLITE_OK is returned.
    02159 ** If execution of the statement failed then an
    02160 ** [SQLITE_ERROR | error code] or [SQLITE_IOERR_READ | extended error code]
    02161 ** is returned.
    02162 **
    02163 ** This routine can be called at any point during the execution of the
    02164 ** [sqlite3_stmt | virtual machine].  If the virtual machine has not
    02165 ** completed execution when this routine is called, that is like
    02166 ** encountering an error or an interrupt.  (See [sqlite3_interrupt()].)
    02167 ** Incomplete updates may be rolled back and transactions cancelled,
    02168 ** depending on the circumstances, and the
    02169 ** [SQLITE_ERROR | result code] returned will be [SQLITE_ABORT].
    02170 */
    02171 int sqlite3_finalize(sqlite3_stmt *pStmt);
    02172
    02173 /*
    02174 ** CAPI3REF: Reset A Prepared Statement Object
    02175 **
    02176 ** The sqlite3_reset() function is called to reset a
    02177 ** [sqlite3_stmt | compiled SQL statement] object.
    02178 ** back to it's initial state, ready to be re-executed.
    02179 ** Any SQL statement variables that had values bound to them using
    02180 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
    02181 ** Use [sqlite3_clear_bindings()] to reset the bindings.
    02182 */
    02183 int sqlite3_reset(sqlite3_stmt *pStmt);
    02184
    02185 /*
    02186 ** CAPI3REF: Create Or Redefine SQL Functions
    02187 **
    02188 ** The following two functions are used to add SQL functions or aggregates
    02189 ** or to redefine the behavior of existing SQL functions or aggregates.  The
    02190 ** difference only between the two is that the second parameter, the
    02191 ** name of the (scalar) function or aggregate, is encoded in UTF-8 for
    02192 ** sqlite3_create_function() and UTF-16 for sqlite3_create_function16().
    02193 **
    02194 ** The first argument is the [sqlite3 | database handle] that holds the
    02195 ** SQL function or aggregate is to be added or redefined. If a single
    02196 ** program uses more than one database handle internally, then SQL
    02197 ** functions or aggregates must be added individually to each database
    02198 ** handle with which they will be used.
    02199 **
    02200 ** The second parameter is the name of the SQL function to be created
    02201 ** or redefined.
    02202 ** The length of the name is limited to 255 bytes, exclusive of the
    02203 ** zero-terminator.  Note that the name length limit is in bytes, not
    02204 ** characters.  Any attempt to create a function with a longer name
    02205 ** will result in an SQLITE_ERROR error.
    02206 **
    02207 ** The third parameter is the number of arguments that the SQL function or
    02208 ** aggregate takes. If this parameter is negative, then the SQL function or
    02209 ** aggregate may take any number of arguments.
    02210 **
    02211 ** The fourth parameter, eTextRep, specifies what
    02212 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
    02213 ** its parameters.  Any SQL function implementation should be able to work
    02214 ** work with UTF-8, UTF-16le, or UTF-16be.  But some implementations may be
    02215 ** more efficient with one encoding than another.  It is allowed to
    02216 ** invoke sqlite3_create_function() or sqlite3_create_function16() multiple
    02217 ** times with the same function but with different values of eTextRep.
    02218 ** When multiple implementations of the same function are available, SQLite
    02219 ** will pick the one that involves the least amount of data conversion.
    02220 ** If there is only a single implementation which does not care what
    02221 ** text encoding is used, then the fourth argument should be
    02222 ** [SQLITE_ANY].
    02223 **
    02224 ** The fifth parameter is an arbitrary pointer.  The implementation
    02225 ** of the function can gain access to this pointer using
    02226 ** [sqlite3_user_data()].
    02227 **
    02228 ** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
    02229 ** pointers to C-language functions that implement the SQL
    02230 ** function or aggregate. A scalar SQL function requires an implementation of
    02231 ** the xFunc callback only, NULL pointers should be passed as the xStep
    02232 ** and xFinal parameters. An aggregate SQL function requires an implementation
    02233 ** of xStep and xFinal and NULL should be passed for xFunc. To delete an
    02234 ** existing SQL function or aggregate, pass NULL for all three function
    02235 ** callback.
    02236 **
    02237 ** It is permitted to register multiple implementations of the same
    02238 ** functions with the same name but with either differing numbers of
    02239 ** arguments or differing perferred text encodings.  SQLite will use
    02240 ** the implementation most closely matches the way in which the
    02241 ** SQL function is used.
    02242 */
    02243 int sqlite3_create_function(
    02244   sqlite3 *,
    02245   const char *zFunctionName,
    02246   int nArg,
    02247   int eTextRep,
    02248   void*,
    02249   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
    02250   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
    02251   void (*xFinal)(sqlite3_context*)
    02252 );
    02253 int sqlite3_create_function16(
    02254   sqlite3*,
    02255   const void *zFunctionName,
    02256   int nArg,
    02257   int eTextRep,
    02258   void*,
    02259   void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
    02260   void (*xStep)(sqlite3_context*,int,sqlite3_value**),
    02261   void (*xFinal)(sqlite3_context*)
    02262 );
    02263
    02264 /*
    02265 ** CAPI3REF: Text Encodings
    02266 **
    02267 ** These constant define integer codes that represent the various
    02268 ** text encodings supported by SQLite.
    02269 */
    02270 #define SQLITE_UTF8           1
    02271 #define SQLITE_UTF16LE        2
    02272 #define SQLITE_UTF16BE        3
    02273 #define SQLITE_UTF16          4    /* Use native byte order */
    02274 #define SQLITE_ANY            5    /* sqlite3_create_function only */
    02275 #define SQLITE_UTF16_ALIGNED  8    /* sqlite3_create_collation only */
    02276
    02277 /*
    02278 ** CAPI3REF: Obsolete Functions
    02279 **
    02280 ** These functions are all now obsolete.  In order to maintain
    02281 ** backwards compatibility with older code, we continue to support
    02282 ** these functions.  However, new development projects should avoid
    02283 ** the use of these functions.  To help encourage people to avoid
    02284 ** using these functions, we are not going to tell you want they do.
    02285 */
    02286 int sqlite3_aggregate_count(sqlite3_context*);
    02287 int sqlite3_expired(sqlite3_stmt*);
    02288 int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
    02289 int sqlite3_global_recover(void);
    02290 void sqlite3_thread_cleanup(void);
    02291
    02292 /*
    02293 ** CAPI3REF: Obtaining SQL Function Parameter Values
    02294 **
    02295 ** The C-language implementation of SQL functions and aggregates uses
    02296 ** this set of interface routines to access the parameter values on
    02297 ** the function or aggregate.
    02298 **
    02299 ** The xFunc (for scalar functions) or xStep (for aggregates) parameters
    02300 ** to [sqlite3_create_function()] and [sqlite3_create_function16()]
    02301 ** define callbacks that implement the SQL functions and aggregates.
    02302 ** The 4th parameter to these callbacks is an array of pointers to
    02303 ** [sqlite3_value] objects.  There is one [sqlite3_value] object for
    02304 ** each parameter to the SQL function.  These routines are used to
    02305 ** extract values from the [sqlite3_value] objects.
    02306 **
    02307 ** These routines work just like the corresponding
    02308 ** [sqlite3_column_blob | sqlite3_column_* routines] except that
    02309 ** these routines take a single [sqlite3_value*] pointer instead
    02310 ** of an [sqlite3_stmt*] pointer and an integer column number.
    02311 **
    02312 ** The sqlite3_value_text16() interface extracts a UTF16 string
    02313 ** in the native byte-order of the host machine.  The
    02314 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
    02315 ** extract UTF16 strings as big-endian and little-endian respectively.
    02316 **
    02317 ** The sqlite3_value_numeric_type() interface attempts to apply
    02318 ** numeric affinity to the value.  This means that an attempt is
    02319 ** made to convert the value to an integer or floating point.  If
    02320 ** such a conversion is possible without loss of information (in order
    02321 ** words if the value is original a string that looks like a number)
    02322 ** then it is done.  Otherwise no conversion occurs.  The
    02323 ** [SQLITE_INTEGER | datatype] after conversion is returned.
    02324 **
    02325 ** Please pay particular attention to the fact that the pointer that
    02326 ** is returned from [sqlite3_value_blob()], [sqlite3_value_text()], or
    02327 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
    02328 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
    02329 ** or [sqlite3_value_text16()].
    02330 **
    02331 ** These routines must be called from the same thread as
    02332 ** the SQL function that supplied the sqlite3_value* parameters.
    02333 ** Or, if the sqlite3_value* argument comes from the [sqlite3_column_value()]
    02334 ** interface, then these routines should be called from the same thread
    02335 ** that ran [sqlite3_column_value()].
    02336 */
    02337 const void *sqlite3_value_blob(sqlite3_value*);
    02338 int sqlite3_value_bytes(sqlite3_value*);
    02339 int sqlite3_value_bytes16(sqlite3_value*);
    02340 double sqlite3_value_double(sqlite3_value*);
    02341 int sqlite3_value_int(sqlite3_value*);
    02342 sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
    02343 const unsigned char *sqlite3_value_text(sqlite3_value*);
    02344 const void *sqlite3_value_text16(sqlite3_value*);
    02345 const void *sqlite3_value_text16le(sqlite3_value*);
    02346 const void *sqlite3_value_text16be(sqlite3_value*);
    02347 int sqlite3_value_type(sqlite3_value*);
    02348 int sqlite3_value_numeric_type(sqlite3_value*);
    02349
    02350 /*
    02351 ** CAPI3REF: Obtain Aggregate Function Context
    02352 **
    02353 ** The implementation of aggregate SQL functions use this routine to allocate
    02354 ** a structure for storing their state.  The first time this routine
    02355 ** is called for a particular aggregate, a new structure of size nBytes
    02356 ** is allocated, zeroed, and returned.  On subsequent calls (for the
    02357 ** same aggregate instance) the same buffer is returned.  The implementation
    02358 ** of the aggregate can use the returned buffer to accumulate data.
    02359 **
    02360 ** The buffer allocated is freed automatically by SQLite whan the aggregate
    02361 ** query concludes.
    02362 **
    02363 ** The first parameter should be a copy of the
    02364 ** [sqlite3_context | SQL function context] that is the first
    02365 ** parameter to the callback routine that implements the aggregate
    02366 ** function.
    02367 **
    02368 ** This routine must be called from the same thread in which
    02369 ** the aggregate SQL function is running.
    02370 */
    02371 void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
    02372
    02373 /*
    02374 ** CAPI3REF: User Data For Functions
    02375 **
    02376 ** The pUserData parameter to the [sqlite3_create_function()]
    02377 ** and [sqlite3_create_function16()] routines
    02378 ** used to register user functions is available to
    02379 ** the implementation of the function using this call.
    02380 **
    02381 ** This routine must be called from the same thread in which
    02382 ** the SQL function is running.
    02383 */
    02384 void *sqlite3_user_data(sqlite3_context*);
    02385
    02386 /*
    02387 ** CAPI3REF: Function Auxiliary Data
    02388 **
    02389 ** The following two functions may be used by scalar SQL functions to
    02390 ** associate meta-data with argument values. If the same value is passed to
    02391 ** multiple invocations of the same SQL function during query execution, under
    02392 ** some circumstances the associated meta-data may be preserved. This may
    02393 ** be used, for example, to add a regular-expression matching scalar
    02394 ** function. The compiled version of the regular expression is stored as
    02395 ** meta-data associated with the SQL value passed as the regular expression
    02396 ** pattern.  The compiled regular expression can be reused on multiple
    02397 ** invocations of the same function so that the original pattern string
    02398 ** does not need to be recompiled on each invocation.
    02399 **
    02400 ** The sqlite3_get_auxdata() interface returns a pointer to the meta-data
    02401 ** associated with the Nth argument value to the current SQL function
    02402 ** call, where N is the second parameter. If no meta-data has been set for
    02403 ** that value, then a NULL pointer is returned.
    02404 **
    02405 ** The sqlite3_set_auxdata() is used to associate meta-data with an SQL
    02406 ** function argument. The third parameter is a pointer to the meta-data
    02407 ** to be associated with the Nth user function argument value. The fourth
    02408 ** parameter specifies a destructor that will be called on the meta-
    02409 ** data pointer to release it when it is no longer required. If the
    02410 ** destructor is NULL, it is not invoked.
    02411 **
    02412 ** In practice, meta-data is preserved between function calls for
    02413 ** expressions that are constant at compile time. This includes literal
    02414 ** values and SQL variables.
    02415 **
    02416 ** These routines must be called from the same thread in which
    02417 ** the SQL function is running.
    02418 */
    02419 void *sqlite3_get_auxdata(sqlite3_context*, int);
    02420 void sqlite3_set_auxdata(sqlite3_context*, int, void*, void (*)(void*));
    02421
    02422
    02423 /*
    02424 ** CAPI3REF: Constants Defining Special Destructor Behavior
    02425 **
    02426 ** These are special value for the destructor that is passed in as the
    02427 ** final argument to routines like [sqlite3_result_blob()].  If the destructor
    02428 ** argument is SQLITE_STATIC, it means that the content pointer is constant
    02429 ** and will never change.  It does not need to be destroyed.  The
    02430 ** SQLITE_TRANSIENT value means that the content will likely change in
    02431 ** the near future and that SQLite should make its own private copy of
    02432 ** the content before returning.
    02433 **
    02434 ** The typedef is necessary to work around problems in certain
    02435 ** C++ compilers.  See ticket #2191.
    02436 */
    02437 typedef void (*sqlite3_destructor_type)(void*);
    02438 #define SQLITE_STATIC      ((sqlite3_destructor_type)0)
    02439 #define SQLITE_TRANSIENT   ((sqlite3_destructor_type)-1)
    02440
    02441 /*
    02442 ** CAPI3REF: Setting The Result Of An SQL Function
    02443 **
    02444 ** These routines are used by the xFunc or xFinal callbacks that
    02445 ** implement SQL functions and aggregates.  See
    02446 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
    02447 ** for additional information.
    02448 **
    02449 ** These functions work very much like the
    02450 ** [sqlite3_bind_blob | sqlite3_bind_*] family of functions used
    02451 ** to bind values to host parameters in prepared statements.
    02452 ** Refer to the
    02453 ** [sqlite3_bind_blob | sqlite3_bind_* documentation] for
    02454 ** additional information.
    02455 **
    02456 ** The sqlite3_result_error() and sqlite3_result_error16() functions
    02457 ** cause the implemented SQL function to throw an exception.  The
    02458 ** parameter to sqlite3_result_error() or sqlite3_result_error16()
    02459 ** is the text of an error message.
    02460 **
    02461 ** The sqlite3_result_toobig() cause the function implementation
    02462 ** to throw and error indicating that a string or BLOB is to long
    02463 ** to represent.
    02464 **
    02465 ** These routines must be called from within the same thread as
    02466 ** the SQL function associated with the [sqlite3_context] pointer.
    02467 */
    02468 void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
    02469 void sqlite3_result_double(sqlite3_context*, double);
    02470 void sqlite3_result_error(sqlite3_context*, const char*, int);
    02471 void sqlite3_result_error16(sqlite3_context*, const void*, int);
    02472 void sqlite3_result_error_toobig(sqlite3_context*);
    02473 void sqlite3_result_error_nomem(sqlite3_context*);
    02474 void sqlite3_result_int(sqlite3_context*, int);
    02475 void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
    02476 void sqlite3_result_null(sqlite3_context*);
    02477 void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
    02478 void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
    02479 void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
    02480 void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
    02481 void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
    02482 void sqlite3_result_zeroblob(sqlite3_context*, int n);
    02483
    02484 /*
    02485 ** CAPI3REF: Define New Collating Sequences
    02486 **
    02487 ** These functions are used to add new collation sequences to the
    02488 ** [sqlite3*] handle specified as the first argument.
    02489 **
    02490 ** The name of the new collation sequence is specified as a UTF-8 string
    02491 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
    02492 ** and a UTF-16 string for sqlite3_create_collation16().  In all cases
    02493 ** the name is passed as the second function argument.
    02494 **
    02495 ** The third argument must be one of the constants [SQLITE_UTF8],
    02496 ** [SQLITE_UTF16LE] or [SQLITE_UTF16BE], indicating that the user-supplied
    02497 ** routine expects to be passed pointers to strings encoded using UTF-8,
    02498 ** UTF-16 little-endian or UTF-16 big-endian respectively.
    02499 **
    02500 ** A pointer to the user supplied routine must be passed as the fifth
    02501 ** argument. If it is NULL, this is the same as deleting the collation
    02502 ** sequence (so that SQLite cannot call it anymore). Each time the user
    02503 ** supplied function is invoked, it is passed a copy of the void* passed as
    02504 ** the fourth argument to sqlite3_create_collation() or
    02505 ** sqlite3_create_collation16() as its first parameter.
    02506 **
    02507 ** The remaining arguments to the user-supplied routine are two strings,
    02508 ** each represented by a [length, data] pair and encoded in the encoding
    02509 ** that was passed as the third argument when the collation sequence was
    02510 ** registered. The user routine should return negative, zero or positive if
    02511 ** the first string is less than, equal to, or greater than the second
    02512 ** string. i.e. (STRING1 - STRING2).
    02513 **
    02514 ** The sqlite3_create_collation_v2() works like sqlite3_create_collation()
    02515 ** excapt that it takes an extra argument which is a destructor for
    02516 ** the collation.  The destructor is called when the collation is
    02517 ** destroyed and is passed a copy of the fourth parameter void* pointer
    02518 ** of the sqlite3_create_collation_v2().  Collations are destroyed when
    02519 ** they are overridden by later calls to the collation creation functions
    02520 ** or when the [sqlite3*] database handle is closed using [sqlite3_close()].
    02521 **
    02522 ** The sqlite3_create_collation_v2() interface is experimental and
    02523 ** subject to change in future releases.  The other collation creation
    02524 ** functions are stable.
    02525 */
    02526 int sqlite3_create_collation(
    02527   sqlite3*,
    02528   const char *zName,
    02529   int eTextRep,
    02530   void*,
    02531   int(*xCompare)(void*,int,const void*,int,const void*)
    02532 );
    02533 int sqlite3_create_collation_v2(
    02534   sqlite3*,
    02535   const char *zName,
    02536   int eTextRep,
    02537   void*,
    02538   int(*xCompare)(void*,int,const void*,int,const void*),
    02539   void(*xDestroy)(void*)
    02540 );
    02541 int sqlite3_create_collation16(
    02542   sqlite3*,
    02543   const char *zName,
    02544   int eTextRep,
    02545   void*,
    02546   int(*xCompare)(void*,int,const void*,int,const void*)
    02547 );
    02548
    02549 /*
    02550 ** CAPI3REF: Collation Needed Callbacks
    02551 **
    02552 ** To avoid having to register all collation sequences before a database
    02553 ** can be used, a single callback function may be registered with the
    02554 ** database handle to be called whenever an undefined collation sequence is
    02555 ** required.
    02556 **
    02557 ** If the function is registered using the sqlite3_collation_needed() API,
    02558 ** then it is passed the names of undefined collation sequences as strings
    02559 ** encoded in UTF-8. If sqlite3_collation_needed16() is used, the names
    02560 ** are passed as UTF-16 in machine native byte order. A call to either
    02561 ** function replaces any existing callback.
    02562 **
    02563 ** When the callback is invoked, the first argument passed is a copy
    02564 ** of the second argument to sqlite3_collation_needed() or
    02565 ** sqlite3_collation_needed16(). The second argument is the database
    02566 ** handle. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE], or
    02567 ** [SQLITE_UTF16LE], indicating the most desirable form of the collation
    02568 ** sequence function required. The fourth parameter is the name of the
    02569 ** required collation sequence.
    02570 **
    02571 ** The callback function should register the desired collation using
    02572 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
    02573 ** [sqlite3_create_collation_v2()].
    02574 */
    02575 int sqlite3_collation_needed(
    02576   sqlite3*,
    02577   void*,
    02578   void(*)(void*,sqlite3*,int eTextRep,const char*)
    02579 );
    02580 int sqlite3_collation_needed16(
    02581   sqlite3*,
    02582   void*,
    02583   void(*)(void*,sqlite3*,int eTextRep,const void*)
    02584 );
    02585
    02586 /*
    02587 ** Specify the key for an encrypted database.  This routine should be
    02588 ** called right after sqlite3_open().
    02589 **
    02590 ** The code to implement this API is not available in the public release
    02591 ** of SQLite.
    02592 */
    02593 int sqlite3_key(
    02594   sqlite3 *db,                   /* Database to be rekeyed */
    02595   const void *pKey, int nKey     /* The key */
    02596 );
    02597
    02598 /*
    02599 ** Change the key on an open database.  If the current database is not
    02600 ** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
    02601 ** database is decrypted.
    02602 **
    02603 ** The code to implement this API is not available in the public release
    02604 ** of SQLite.
    02605 */
    02606 int sqlite3_rekey(
    02607   sqlite3 *db,                   /* Database to be rekeyed */
    02608   const void *pKey, int nKey     /* The new key */
    02609 );
    02610
    02611 /*
    02612 ** CAPI3REF:  Suspend Execution For A Short Time
    02613 **
    02614 ** This function causes the current thread to suspend execution
    02615 ** a number of milliseconds specified in its parameter.
    02616 **
    02617 ** If the operating system does not support sleep requests with
    02618 ** millisecond time resolution, then the time will be rounded up to
    02619 ** the nearest second. The number of milliseconds of sleep actually
    02620 ** requested from the operating system is returned.
    02621 **
    02622 ** SQLite implements this interface by calling the xSleep()
    02623 ** method of the default [sqlite3_vfs] object.
    02624 */
    02625 int sqlite3_sleep(int);
    02626
    02627 /*
    02628 ** CAPI3REF:  Name Of The Folder Holding Temporary Files
    02629 **
    02630 ** If this global variable is made to point to a string which is
    02631 ** the name of a folder (a.ka. directory), then all temporary files
    02632 ** created by SQLite will be placed in that directory.  If this variable
    02633 ** is NULL pointer, then SQLite does a search for an appropriate temporary
    02634 ** file directory.
    02635 **
    02636 ** It is not safe to modify this variable once a database connection
    02637 ** has been opened.  It is intended that this variable be set once
    02638 ** as part of process initialization and before any SQLite interface
    02639 ** routines have been call and remain unchanged thereafter.
    02640 */
    02641 SQLITE_EXTERN char *sqlite3_temp_directory;
    02642
    02643 /*
    02644 ** CAPI3REF:  Test To See If The Database Is In Auto-Commit Mode
    02645 **
    02646 ** Test to see whether or not the database connection is in autocommit
    02647 ** mode.  Return TRUE if it is and FALSE if not.  Autocommit mode is on
    02648 ** by default.  Autocommit is disabled by a BEGIN statement and reenabled
    02649 ** by the next COMMIT or ROLLBACK.
    02650 **
    02651 ** If another thread changes the autocommit status of the database
    02652 ** connection while this routine is running, then the return value
    02653 ** is undefined.
    02654 */
    02655 int sqlite3_get_autocommit(sqlite3*);
    02656
    02657 /*
    02658 ** CAPI3REF:  Find The Database Handle Associated With A Prepared Statement
    02659 **
    02660 ** Return the [sqlite3*] database handle to which a
    02661 ** [sqlite3_stmt | prepared statement] belongs.
    02662 ** This is the same database handle that was
    02663 ** the first argument to the [sqlite3_prepare_v2()] or its variants
    02664 ** that was used to create the statement in the first place.
    02665 */
    02666 sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
    02667
    02668
    02669 /*
    02670 ** CAPI3REF: Commit And Rollback Notification Callbacks
    02671 **
    02672 ** These routines
    02673 ** register callback functions to be invoked whenever a transaction
    02674 ** is committed or rolled back.  The pArg argument is passed through
    02675 ** to the callback.  If the callback on a commit hook function
    02676 ** returns non-zero, then the commit is converted into a rollback.
    02677 **
    02678 ** If another function was previously registered, its pArg value is returned.
    02679 ** Otherwise NULL is returned.
    02680 **
    02681 ** Registering a NULL function disables the callback.
    02682 **
    02683 ** For the purposes of this API, a transaction is said to have been
    02684 ** rolled back if an explicit "ROLLBACK" statement is executed, or
    02685 ** an error or constraint causes an implicit rollback to occur. The
    02686 ** callback is not invoked if a transaction is automatically rolled
    02687 ** back because the database connection is closed.
    02688 **
    02689 ** These are experimental interfaces and are subject to change.
    02690 */
    02691 void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
    02692 void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
    02693
    02694 /*
    02695 ** CAPI3REF: Data Change Notification Callbacks
    02696 **
    02697 ** Register a callback function with the database connection identified by the
    02698 ** first argument to be invoked whenever a row is updated, inserted or deleted.
    02699 ** Any callback set by a previous call to this function for the same
    02700 ** database connection is overridden.
    02701 **
    02702 ** The second argument is a pointer to the function to invoke when a
    02703 ** row is updated, inserted or deleted. The first argument to the callback is
    02704 ** a copy of the third argument to sqlite3_update_hook(). The second callback
    02705 ** argument is one of SQLITE_INSERT, SQLITE_DELETE or SQLITE_UPDATE, depending
    02706 ** on the operation that caused the callback to be invoked. The third and
    02707 ** fourth arguments to the callback contain pointers to the database and
    02708 ** table name containing the affected row. The final callback parameter is
    02709 ** the rowid of the row. In the case of an update, this is the rowid after
    02710 ** the update takes place.
    02711 **
    02712 ** The update hook is not invoked when internal system tables are
    02713 ** modified (i.e. sqlite_master and sqlite_sequence).
    02714 **
    02715 ** If another function was previously registered, its pArg value is returned.
    02716 ** Otherwise NULL is returned.
    02717 */
    02718 void *sqlite3_update_hook(
    02719   sqlite3*,
    02720   void(*)(void *,int ,char const *,char const *,sqlite3_int64),
    02721   void*
    02722 );
    02723
    02724 /*
    02725 ** CAPI3REF:  Enable Or Disable Shared Pager Cache
    02726 **
    02727 ** This routine enables or disables the sharing of the database cache
    02728 ** and schema data structures between connections to the same database.
    02729 ** Sharing is enabled if the argument is true and disabled if the argument
    02730 ** is false.
    02731 **
    02732 ** Beginning in SQLite version 3.5.0, cache sharing is enabled and disabled
    02733 ** for an entire process.  In prior versions of SQLite, sharing was
    02734 ** enabled or disabled for each thread separately.
    02735 **
    02736 ** The cache sharing mode set by this interface effects all subsequent
    02737 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
    02738 ** Existing database connections continue use the sharing mode that was
    02739 ** in effect at the time they were opened.
    02740 **
    02741 ** Virtual tables cannot be used with a shared cache.  When shared
    02742 ** cache is enabled, the [sqlite3_create_module()] API used to register
    02743 ** virtual tables will always return an error.
    02744 **
    02745 ** This routine returns [SQLITE_OK] if shared cache was
    02746 ** enabled or disabled successfully.  An [SQLITE_ERROR | error code]
    02747 ** is returned otherwise.
    02748 **
    02749 ** Shared cache is disabled by default.  But this might change in
    02750 ** future releases of SQLite.  Applications that care about shared
    02751 ** cache setting should set it explicitly.
    02752 */
    02753 int sqlite3_enable_shared_cache(int);
    02754
    02755 /*
    02756 ** CAPI3REF:  Attempt To Free Heap Memory
    02757 **
    02758 ** Attempt to free N bytes of heap memory by deallocating non-essential
    02759 ** memory allocations held by the database library (example: memory
    02760 ** used to cache database pages to improve performance).
    02761 */
    02762 int sqlite3_release_memory(int);
    02763
    02764 /*
    02765 ** CAPI3REF:  Impose A Limit On Heap Size
    02766 **
    02767 ** Place a "soft" limit on the amount of heap memory that may be allocated
    02768 ** by SQLite.  If an internal allocation is requested
    02769 ** that would exceed the specified limit, [sqlite3_release_memory()] is
    02770 ** invoked one or more times to free up some space before the allocation
    02771 ** is made.
    02772 **
    02773 ** The limit is called "soft", because if [sqlite3_release_memory()] cannot
    02774 ** free sufficient memory to prevent the limit from being exceeded,
    02775 ** the memory is allocated anyway and the current operation proceeds.
    02776 **
    02777 ** A negative or zero value for N means that there is no soft heap limit and
    02778 ** [sqlite3_release_memory()] will only be called when memory is exhausted.
    02779 ** The default value for the soft heap limit is zero.
    02780 **
    02781 ** SQLite makes a best effort to honor the soft heap limit.  But if it
    02782 ** is unable to reduce memory usage below the soft limit, execution will
    02783 ** continue without error or notification.  This is why the limit is
    02784 ** called a "soft" limit.  It is advisory only.
    02785 **
    02786 ** The soft heap limit is implemented using the [sqlite3_memory_alarm()]
    02787 ** interface.  Only a single memory alarm is available in the default
    02788 ** implementation.  This means that if the application also uses the
    02789 ** memory alarm interface it will interfere with the operation of the
    02790 ** soft heap limit and undefined behavior will result.
    02791 **
    02792 ** Prior to SQLite version 3.5.0, this routine only constrained the memory
    02793 ** allocated by a single thread - the same thread in which this routine
    02794 ** runs.  Beginning with SQLite version 3.5.0, the soft heap limit is
    02795 ** applied to all threads.  The value specified for the soft heap limit
    02796 ** is an upper bound on the total memory allocation for all threads.  In
    02797 ** version 3.5.0 there is no mechanism for limiting the heap usage for
    02798 ** individual threads.
    02799 */
    02800 void sqlite3_soft_heap_limit(int);
    02801
    02802 /*
    02803 ** CAPI3REF:  Extract Metadata About A Column Of A Table
    02804 **
    02805 ** This routine
    02806 ** returns meta-data about a specific column of a specific database
    02807 ** table accessible using the connection handle passed as the first function
    02808 ** argument.
    02809 **
    02810 ** The column is identified by the second, third and fourth parameters to
    02811 ** this function. The second parameter is either the name of the database
    02812 ** (i.e. "main", "temp" or an attached database) containing the specified
    02813 ** table or NULL. If it is NULL, then all attached databases are searched
    02814 ** for the table using the same algorithm as the database engine uses to
    02815 ** resolve unqualified table references.
    02816 **
    02817 ** The third and fourth parameters to this function are the table and column
    02818 ** name of the desired column, respectively. Neither of these parameters
    02819 ** may be NULL.
    02820 **
    02821 ** Meta information is returned by writing to the memory locations passed as
    02822 ** the 5th and subsequent parameters to this function. Any of these
    02823 ** arguments may be NULL, in which case the corresponding element of meta
    02824 ** information is ommitted.
    02825 **
    02826 ** <pre>
    02827 ** Parameter     Output Type      Description
    02828 ** -----------------------------------
    02829 **
    02830 **   5th         const char*      Data type
    02831 **   6th         const char*      Name of the default collation sequence
    02832 **   7th         int              True if the column has a NOT NULL constraint
    02833 **   8th         int              True if the column is part of the PRIMARY KEY
    02834 **   9th         int              True if the column is AUTOINCREMENT
    02835 ** </pre>
    02836 **
    02837 **
    02838 ** The memory pointed to by the character pointers returned for the
    02839 ** declaration type and collation sequence is valid only until the next
    02840 ** call to any sqlite API function.
    02841 **
    02842 ** If the specified table is actually a view, then an error is returned.
    02843 **
    02844 ** If the specified column is "rowid", "oid" or "_rowid_" and an
    02845 ** INTEGER PRIMARY KEY column has been explicitly declared, then the output
    02846 ** parameters are set for the explicitly declared column. If there is no
    02847 ** explicitly declared IPK column, then the output parameters are set as
    02848 ** follows:
    02849 **
    02850 ** <pre>
    02851 **     data type: "INTEGER"
    02852 **     collation sequence: "BINARY"
    02853 **     not null: 0
    02854 **     primary key: 1
    02855 **     auto increment: 0
    02856 ** </pre>
    02857 **
    02858 ** This function may load one or more schemas from database files. If an
    02859 ** error occurs during this process, or if the requested table or column
    02860 ** cannot be found, an SQLITE error code is returned and an error message
    02861 ** left in the database handle (to be retrieved using sqlite3_errmsg()).
    02862 **
    02863 ** This API is only available if the library was compiled with the
    02864 ** SQLITE_ENABLE_COLUMN_METADATA preprocessor symbol defined.
    02865 */
    02866 int sqlite3_table_column_metadata(
    02867   sqlite3 *db,                /* Connection handle */
    02868   const char *zDbName,        /* Database name or NULL */
    02869   const char *zTableName,     /* Table name */
    02870   const char *zColumnName,    /* Column name */
    02871   char const **pzDataType,    /* OUTPUT: Declared data type */
    02872   char const **pzCollSeq,     /* OUTPUT: Collation sequence name */
    02873   int *pNotNull,              /* OUTPUT: True if NOT NULL constraint exists */
    02874   int *pPrimaryKey,           /* OUTPUT: True if column part of PK */
    02875   int *pAutoinc               /* OUTPUT: True if colums is auto-increment */
    02876 );
    02877
    02878 /*
    02879 ** CAPI3REF: Load An Extension
    02880 **
    02881 ** Attempt to load an SQLite extension library contained in the file
    02882 ** zFile.  The entry point is zProc.  zProc may be 0 in which case the
    02883 ** name of the entry point defaults to "sqlite3_extension_init".
    02884 **
    02885 ** Return [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
    02886 **
    02887 ** If an error occurs and pzErrMsg is not 0, then fill *pzErrMsg with
    02888 ** error message text.  The calling function should free this memory
    02889 ** by calling [sqlite3_free()].
    02890 **
    02891 ** Extension loading must be enabled using [sqlite3_enable_load_extension()]
    02892 ** prior to calling this API or an error will be returned.
    02893 */
    02894 int sqlite3_load_extension(
    02895   sqlite3 *db,          /* Load the extension into this database connection */
    02896   const char *zFile,    /* Name of the shared library containing extension */
    02897   const char *zProc,    /* Entry point.  Derived from zFile if 0 */
    02898   char **pzErrMsg       /* Put error message here if not 0 */
    02899 );
    02900
    02901 /*
    02902 ** CAPI3REF:  Enable Or Disable Extension Loading
    02903 **
    02904 ** So as not to open security holes in older applications that are
    02905 ** unprepared to deal with extension loading, and as a means of disabling
    02906 ** extension loading while evaluating user-entered SQL, the following
    02907 ** API is provided to turn the [sqlite3_load_extension()] mechanism on and
    02908 ** off.  It is off by default.  See ticket #1863.
    02909 **
    02910 ** Call this routine with onoff==1 to turn extension loading on
    02911 ** and call it with onoff==0 to turn it back off again.
    02912 */
    02913 int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
    02914
    02915 /*
    02916 ** CAPI3REF: Make Arrangements To Automatically Load An Extension
    02917 **
    02918 ** Register an extension entry point that is automatically invoked
    02919 ** whenever a new database connection is opened using
    02920 ** [sqlite3_open()], [sqlite3_open16()], or [sqlite3_open_v2()].
    02921 **
    02922 ** This API can be invoked at program startup in order to register
    02923 ** one or more statically linked extensions that will be available
    02924 ** to all new database connections.
    02925 **
    02926 ** Duplicate extensions are detected so calling this routine multiple
    02927 ** times with the same extension is harmless.
    02928 **
    02929 ** This routine stores a pointer to the extension in an array
    02930 ** that is obtained from malloc().  If you run a memory leak
    02931 ** checker on your program and it reports a leak because of this
    02932 ** array, then invoke [sqlite3_automatic_extension_reset()] prior
    02933 ** to shutdown to free the memory.
    02934 **
    02935 ** Automatic extensions apply across all threads.
    02936 **
    02937 ** This interface is experimental and is subject to change or
    02938 ** removal in future releases of SQLite.
    02939 */
    02940 int sqlite3_auto_extension(void *xEntryPoint);
    02941
    02942
    02943 /*
    02944 ** CAPI3REF: Reset Automatic Extension Loading
    02945 **
    02946 ** Disable all previously registered automatic extensions.  This
    02947 ** routine undoes the effect of all prior [sqlite3_automatic_extension()]
    02948 ** calls.
    02949 **
    02950 ** This call disabled automatic extensions in all threads.
    02951 **
    02952 ** This interface is experimental and is subject to change or
    02953 ** removal in future releases of SQLite.
    02954 */
    02955 void sqlite3_reset_auto_extension(void);
    02956
    02957
    02958 /*
    02959 ****** EXPERIMENTAL - subject to change without notice **************
    02960 **
    02961 ** The interface to the virtual-table mechanism is currently considered
    02962 ** to be experimental.  The interface might change in incompatible ways.
    02963 ** If this is a problem for you, do not use the interface at this time.
    02964 **
    02965 ** When the virtual-table mechanism stablizes, we will declare the
    02966 ** interface fixed, support it indefinitely, and remove this comment.
    02967 */
    02968
    02969 /*
    02970 ** Structures used by the virtual table interface
    02971 */
    02972 typedef struct sqlite3_vtab sqlite3_vtab;
    02973 typedef struct sqlite3_index_info sqlite3_index_info;
    02974 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
    02975 typedef struct sqlite3_module sqlite3_module;
    02976
    02977 /*
    02978 ** A module is a class of virtual tables.  Each module is defined
    02979 ** by an instance of the following structure.  This structure consists
    02980 ** mostly of methods for the module.
    02981 */
    02982 struct sqlite3_module {
    02983   int iVersion;
    02984   int (*xCreate)(sqlite3*, void *pAux,
    02985                int argc, const char *const*argv,
    02986                sqlite3_vtab **ppVTab, char**);
    02987   int (*xConnect)(sqlite3*, void *pAux,
    02988                int argc, const char *const*argv,
    02989                sqlite3_vtab **ppVTab, char**);
    02990   int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
    02991   int (*xDisconnect)(sqlite3_vtab *pVTab);
    02992   int (*xDestroy)(sqlite3_vtab *pVTab);
    02993   int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
    02994   int (*xClose)(sqlite3_vtab_cursor*);
    02995   int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
    02996                 int argc, sqlite3_value **argv);
    02997   int (*xNext)(sqlite3_vtab_cursor*);
    02998   int (*xEof)(sqlite3_vtab_cursor*);
    02999   int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
    03000   int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
    03001   int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
    03002   int (*xBegin)(sqlite3_vtab *pVTab);
    03003   int (*xSync)(sqlite3_vtab *pVTab);
    03004   int (*xCommit)(sqlite3_vtab *pVTab);
    03005   int (*xRollback)(sqlite3_vtab *pVTab);
    03006   int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
    03007                        void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
    03008                        void **ppArg);
    03009
    03010   int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
    03011 };
    03012
    03013 /*
    03014 ** The sqlite3_index_info structure and its substructures is used to
    03015 ** pass information into and receive the reply from the xBestIndex
    03016 ** method of an sqlite3_module.  The fields under **Inputs** are the
    03017 ** inputs to xBestIndex and are read-only.  xBestIndex inserts its
    03018 ** results into the **Outputs** fields.
    03019 **
    03020 ** The aConstraint[] array records WHERE clause constraints of the
    03021 ** form:
    03022 **
    03023 **         column OP expr
    03024 **
    03025 ** Where OP is =, <, <=, >, or >=.  The particular operator is stored
    03026 ** in aConstraint[].op.  The index of the column is stored in
    03027 ** aConstraint[].iColumn.  aConstraint[].usable is TRUE if the
    03028 ** expr on the right-hand side can be evaluated (and thus the constraint
    03029 ** is usable) and false if it cannot.
    03030 **
    03031 ** The optimizer automatically inverts terms of the form "expr OP column"
    03032 ** and makes other simplificatinos to the WHERE clause in an attempt to
    03033 ** get as many WHERE clause terms into the form shown above as possible.
    03034 ** The aConstraint[] array only reports WHERE clause terms in the correct
    03035 ** form that refer to the particular virtual table being queried.
    03036 **
    03037 ** Information about the ORDER BY clause is stored in aOrderBy[].
    03038 ** Each term of aOrderBy records a column of the ORDER BY clause.
    03039 **
    03040 ** The xBestIndex method must fill aConstraintUsage[] with information
    03041 ** about what parameters to pass to xFilter.  If argvIndex>0 then
    03042 ** the right-hand side of the corresponding aConstraint[] is evaluated
    03043 ** and becomes the argvIndex-th entry in argv.  If aConstraintUsage[].omit
    03044 ** is true, then the constraint is assumed to be fully handled by the
    03045 ** virtual table and is not checked again by SQLite.
    03046 **
    03047 ** The idxNum and idxPtr values are recorded and passed into xFilter.
    03048 ** sqlite3_free() is used to free idxPtr if needToFreeIdxPtr is true.
    03049 **
    03050 ** The orderByConsumed means that output from xFilter will occur in
    03051 ** the correct order to satisfy the ORDER BY clause so that no separate
    03052 ** sorting step is required.
    03053 **
    03054 ** The estimatedCost value is an estimate of the cost of doing the
    03055 ** particular lookup.  A full scan of a table with N entries should have
    03056 ** a cost of N.  A binary search of a table of N entries should have a
    03057 ** cost of approximately log(N).
    03058 */
    03059 struct sqlite3_index_info {
    03060   /* Inputs */
    03061   const int nConstraint;     /* Number of entries in aConstraint */
    03062   const struct sqlite3_index_constraint {
    03063      int iColumn;              /* Column on left-hand side of constraint */
    03064      unsigned char op;         /* Constraint operator */
    03065      unsigned char usable;     /* True if this constraint is usable */
    03066      int iTermOffset;          /* Used internally - xBestIndex should ignore */
    03067   } *const aConstraint;      /* Table of WHERE clause constraints */
    03068   const int nOrderBy;        /* Number of terms in the ORDER BY clause */
    03069   const struct sqlite3_index_orderby {
    03070      int iColumn;              /* Column number */
    03071      unsigned char desc;       /* True for DESC.  False for ASC. */
    03072   } *const aOrderBy;         /* The ORDER BY clause */
    03073
    03074   /* Outputs */
    03075   struct sqlite3_index_constraint_usage {
    03076     int argvIndex;           /* if >0, constraint is part of argv to xFilter */
    03077     unsigned char omit;      /* Do not code a test for this constraint */
    03078   } *const aConstraintUsage;
    03079   int idxNum;                /* Number used to identify the index */
    03080   char *idxStr;              /* String, possibly obtained from sqlite3_malloc */
    03081   int needToFreeIdxStr;      /* Free idxStr using sqlite3_free() if true */
    03082   int orderByConsumed;       /* True if output is already ordered */
    03083   double estimatedCost;      /* Estimated cost of using this index */
    03084 };
    03085 #define SQLITE_INDEX_CONSTRAINT_EQ    2
    03086 #define SQLITE_INDEX_CONSTRAINT_GT    4
    03087 #define SQLITE_INDEX_CONSTRAINT_LE    8
    03088 #define SQLITE_INDEX_CONSTRAINT_LT    16
    03089 #define SQLITE_INDEX_CONSTRAINT_GE    32
    03090 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
    03091
    03092 /*
    03093 ** This routine is used to register a new module name with an SQLite
    03094 ** connection.  Module names must be registered before creating new
    03095 ** virtual tables on the module, or before using preexisting virtual
    03096 ** tables of the module.
    03097 */
    03098 int sqlite3_create_module(
    03099   sqlite3 *db,               /* SQLite connection to register module with */
    03100   const char *zName,         /* Name of the module */
    03101   const sqlite3_module *,    /* Methods for the module */
    03102   void *                     /* Client data for xCreate/xConnect */
    03103 );
    03104
    03105 /*
    03106 ** This routine is identical to the sqlite3_create_module() method above,
    03107 ** except that it allows a destructor function to be specified. It is
    03108 ** even more experimental than the rest of the virtual tables API.
    03109 */
    03110 int sqlite3_create_module_v2(
    03111   sqlite3 *db,               /* SQLite connection to register module with */
    03112   const char *zName,         /* Name of the module */
    03113   const sqlite3_module *,    /* Methods for the module */
    03114   void *,                    /* Client data for xCreate/xConnect */
    03115   void(*xDestroy)(void*)     /* Module destructor function */
    03116 );
    03117
    03118 /*
    03119 ** Every module implementation uses a subclass of the following structure
    03120 ** to describe a particular instance of the module.  Each subclass will
    03121 ** be taylored to the specific needs of the module implementation.   The
    03122 ** purpose of this superclass is to define certain fields that are common
    03123 ** to all module implementations.
    03124 **
    03125 ** Virtual tables methods can set an error message by assigning a
    03126 ** string obtained from sqlite3_mprintf() to zErrMsg.  The method should
    03127 ** take care that any prior string is freed by a call to sqlite3_free()
    03128 ** prior to assigning a new string to zErrMsg.  After the error message
    03129 ** is delivered up to the client application, the string will be automatically
    03130 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.  Note
    03131 ** that sqlite3_mprintf() and sqlite3_free() are used on the zErrMsg field
    03132 ** since virtual tables are commonly implemented in loadable extensions which
    03133 ** do not have access to sqlite3MPrintf() or sqlite3Free().
    03134 */
    03135 struct sqlite3_vtab {
    03136   const sqlite3_module *pModule;  /* The module for this virtual table */
    03137   int nRef;                       /* Used internally */
    03138   char *zErrMsg;                  /* Error message from sqlite3_mprintf() */
    03139   /* Virtual table implementations will typically add additional fields */
    03140 };
    03141
    03142 /* Every module implementation uses a subclass of the following structure
    03143 ** to describe cursors that point into the virtual table and are used
    03144 ** to loop through the virtual table.  Cursors are created using the
    03145 ** xOpen method of the module.  Each module implementation will define
    03146 ** the content of a cursor structure to suit its own needs.
    03147 **
    03148 ** This superclass exists in order to define fields of the cursor that
    03149 ** are common to all implementations.
    03150 */
    03151 struct sqlite3_vtab_cursor {
    03152   sqlite3_vtab *pVtab;      /* Virtual table of this cursor */
    03153   /* Virtual table implementations will typically add additional fields */
    03154 };
    03155
    03156 /*
    03157 ** The xCreate and xConnect methods of a module use the following API
    03158 ** to declare the format (the names and datatypes of the columns) of
    03159 ** the virtual tables they implement.
    03160 */
    03161 int sqlite3_declare_vtab(sqlite3*, const char *zCreateTable);
    03162
    03163 /*
    03164 ** Virtual tables can provide alternative implementations of functions
    03165 ** using the xFindFunction method.  But global versions of those functions
    03166 ** must exist in order to be overloaded.
    03167 **
    03168 ** This API makes sure a global version of a function with a particular
    03169 ** name and number of parameters exists.  If no such function exists
    03170 ** before this API is called, a new function is created.  The implementation
    03171 ** of the new function always causes an exception to be thrown.  So
    03172 ** the new function is not good for anything by itself.  Its only
    03173 ** purpose is to be a place-holder function that can be overloaded
    03174 ** by virtual tables.
    03175 **
    03176 ** This API should be considered part of the virtual table interface,
    03177 ** which is experimental and subject to change.
    03178 */
    03179 int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
    03180
    03181 /*
    03182 ** The interface to the virtual-table mechanism defined above (back up
    03183 ** to a comment remarkably similar to this one) is currently considered
    03184 ** to be experimental.  The interface might change in incompatible ways.
    03185 ** If this is a problem for you, do not use the interface at this time.
    03186 **
    03187 ** When the virtual-table mechanism stablizes, we will declare the
    03188 ** interface fixed, support it indefinitely, and remove this comment.
    03189 **
    03190 ****** EXPERIMENTAL - subject to change without notice **************
    03191 */
    03192
    03193 /*
    03194 ** CAPI3REF: A Handle To An Open BLOB
    03195 **
    03196 ** An instance of the following opaque structure is used to
    03197 ** represent an blob-handle.  A blob-handle is created by
    03198 ** [sqlite3_blob_open()] and destroyed by [sqlite3_blob_close()].
    03199 ** The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
    03200 ** can be used to read or write small subsections of the blob.
    03201 ** The [sqltie3_blob_size()] interface returns the size of the
    03202 ** blob in bytes.
    03203 */
    03204 typedef struct sqlite3_blob sqlite3_blob;
    03205
    03206 /*
    03207 ** CAPI3REF: Open A BLOB For Incremental I/O
    03208 **
    03209 ** Open a handle to the blob located in row iRow,, column zColumn,
    03210 ** table zTable in database zDb. i.e. the same blob that would
    03211 ** be selected by:
    03212 **
    03213 ** <pre>
    03214 **     SELECT zColumn FROM zDb.zTable WHERE rowid = iRow;
    03215 ** </pre>
    03216 **
    03217 ** If the flags parameter is non-zero, the blob is opened for
    03218 ** read and write access. If it is zero, the blob is opened for read
    03219 ** access.
    03220 **
    03221 ** On success, [SQLITE_OK] is returned and the new
    03222 ** [sqlite3_blob | blob handle] is written to *ppBlob.
    03223 ** Otherwise an error code is returned and
    03224 ** any value written to *ppBlob should not be used by the caller.
    03225 ** This function sets the database-handle error code and message
    03226 ** accessible via [sqlite3_errcode()] and [sqlite3_errmsg()].
    03227 */
    03228 int sqlite3_blob_open(
    03229   sqlite3*,
    03230   const char *zDb,
    03231   const char *zTable,
    03232   const char *zColumn,
    03233   sqlite3_int64 iRow,
    03234   int flags,
    03235   sqlite3_blob **ppBlob
    03236 );
    03237
    03238 /*
    03239 ** CAPI3REF:  Close A BLOB Handle
    03240 **
    03241 ** Close an open [sqlite3_blob | blob handle].
    03242 */
    03243 int sqlite3_blob_close(sqlite3_blob *);
    03244
    03245 /*
    03246 ** CAPI3REF:  Return The Size Of An Open BLOB
    03247 **
    03248 ** Return the size in bytes of the blob accessible via the open
    03249 ** [sqlite3_blob | blob-handle] passed as an argument.
    03250 */
    03251 int sqlite3_blob_bytes(sqlite3_blob *);
    03252
    03253 /*
    03254 ** CAPI3REF:  Read Data From A BLOB Incrementally
    03255 **
    03256 ** This function is used to read data from an open
    03257 ** [sqlite3_blob | blob-handle] into a caller supplied buffer.
    03258 ** n bytes of data are copied into buffer
    03259 ** z from the open blob, starting at offset iOffset.
    03260 **
    03261 ** On success, SQLITE_OK is returned. Otherwise, an
    03262 ** [SQLITE_ERROR | SQLite error code] or an
    03263 ** [SQLITE_IOERR_READ | extended error code] is returned.
    03264 */
    03265 int sqlite3_blob_read(sqlite3_blob *, void *z, int n, int iOffset);
    03266
    03267 /*
    03268 ** CAPI3REF:  Write Data Into A BLOB Incrementally
    03269 **
    03270 ** This function is used to write data into an open
    03271 ** [sqlite3_blob | blob-handle] from a user supplied buffer.
    03272 ** n bytes of data are copied from the buffer
    03273 ** pointed to by z into the open blob, starting at offset iOffset.
    03274 **
    03275 ** If the [sqlite3_blob | blob-handle] passed as the first argument
    03276 ** was not opened for writing (the flags parameter to [sqlite3_blob_open()]
    03277 *** was zero), this function returns [SQLITE_READONLY].
    03278 **
    03279 ** This function may only modify the contents of the blob, it is
    03280 ** not possible to increase the size of a blob using this API. If
    03281 ** offset iOffset is less than n bytes from the end of the blob,
    03282 ** [SQLITE_ERROR] is returned and no data is written.
    03283 **
    03284 ** On success, SQLITE_OK is returned. Otherwise, an
    03285 ** [SQLITE_ERROR | SQLite error code] or an
    03286 ** [SQLITE_IOERR_READ | extended error code] is returned.
    03287 */
    03288 int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
    03289
    03290 /*
    03291 ** CAPI3REF:  Virtual File System Objects
    03292 **
    03293 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
    03294 ** that SQLite uses to interact
    03295 ** with the underlying operating system.  Most builds come with a
    03296 ** single default VFS that is appropriate for the host computer.
    03297 ** New VFSes can be registered and existing VFSes can be unregistered.
    03298 ** The following interfaces are provided.
    03299 **
    03300 ** The sqlite3_vfs_find() interface returns a pointer to a VFS given its
    03301 ** name.  Names are case sensitive.  If there is no match, a NULL
    03302 ** pointer is returned.  If zVfsName is NULL then the default
    03303 ** VFS is returned.
    03304 **
    03305 ** New VFSes are registered with sqlite3_vfs_register().  Each
    03306 ** new VFS becomes the default VFS if the makeDflt flag is set.
    03307 ** The same VFS can be registered multiple times without injury.
    03308 ** To make an existing VFS into the default VFS, register it again
    03309 ** with the makeDflt flag set.  If two different VFSes with the
    03310 ** same name are registered, the behavior is undefined.  If a
    03311 ** VFS is registered with a name that is NULL or an empty string,
    03312 ** then the behavior is undefined.
    03313 **
    03314 ** Unregister a VFS with the sqlite3_vfs_unregister() interface.
    03315 ** If the default VFS is unregistered, another VFS is chosen as
    03316 ** the default.  The choice for the new VFS is arbitrary.
    03317 */
    03318 sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
    03319 int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
    03320 int sqlite3_vfs_unregister(sqlite3_vfs*);
    03321
    03322 /*
    03323 ** CAPI3REF: Mutexes
    03324 **
    03325 ** The SQLite core uses these routines for thread
    03326 ** synchronization.  Though they are intended for internal
    03327 ** use by SQLite, code that links against SQLite is
    03328 ** permitted to use any of these routines.
    03329 **
    03330 ** The SQLite source code contains multiple implementations
    03331 ** of these mutex routines.  An appropriate implementation
    03332 ** is selected automatically at compile-time.  The following
    03333 ** implementations are available in the SQLite core:
    03334 **
    03335 ** <ul>
    03336 ** <li>   SQLITE_MUTEX_OS2
    03337 ** <li>   SQLITE_MUTEX_PTHREAD
    03338 ** <li>   SQLITE_MUTEX_W32
    03339 ** <li>   SQLITE_MUTEX_NOOP
    03340 ** </ul>
    03341 **
    03342 ** The SQLITE_MUTEX_NOOP implementation is a set of routines
    03343 ** that does no real locking and is appropriate for use in
    03344 ** a single-threaded application.  The SQLITE_MUTEX_OS2,
    03345 ** SQLITE_MUTEX_PTHREAD, and SQLITE_MUTEX_W32 implementations
    03346 ** are appropriate for use on os/2, unix, and windows.
    03347 **
    03348 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
    03349 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
    03350 ** implementation is included with the library.  The
    03351 ** mutex interface routines defined here become external
    03352 ** references in the SQLite library for which implementations
    03353 ** must be provided by the application.  This facility allows an
    03354 ** application that links against SQLite to provide its own mutex
    03355 ** implementation without having to modify the SQLite core.
    03356 **
    03357 ** The sqlite3_mutex_alloc() routine allocates a new
    03358 ** mutex and returns a pointer to it.  If it returns NULL
    03359 ** that means that a mutex could not be allocated.  SQLite
    03360 ** will unwind its stack and return an error.  The argument
    03361 ** to sqlite3_mutex_alloc() is one of these integer constants:
    03362 **
    03363 ** <ul>
    03364 ** <li>  SQLITE_MUTEX_FAST
    03365 ** <li>  SQLITE_MUTEX_RECURSIVE
    03366 ** <li>  SQLITE_MUTEX_STATIC_MASTER
    03367 ** <li>  SQLITE_MUTEX_STATIC_MEM
    03368 ** <li>  SQLITE_MUTEX_STATIC_MEM2
    03369 ** <li>  SQLITE_MUTEX_STATIC_PRNG
    03370 ** <li>  SQLITE_MUTEX_STATIC_LRU
    03371 ** </ul>
    03372 **
    03373 ** The first two constants cause sqlite3_mutex_alloc() to create
    03374 ** a new mutex.  The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
    03375 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
    03376 ** The mutex implementation does not need to make a distinction
    03377 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
    03378 ** not want to.  But SQLite will only request a recursive mutex in
    03379 ** cases where it really needs one.  If a faster non-recursive mutex
    03380 ** implementation is available on the host platform, the mutex subsystem
    03381 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
    03382 **
    03383 ** The other allowed parameters to sqlite3_mutex_alloc() each return
    03384 ** a pointer to a static preexisting mutex.  Four static mutexes are
    03385 ** used by the current version of SQLite.  Future versions of SQLite
    03386 ** may add additional static mutexes.  Static mutexes are for internal
    03387 ** use by SQLite only.  Applications that use SQLite mutexes should
    03388 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
    03389 ** SQLITE_MUTEX_RECURSIVE.
    03390 **
    03391 ** Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
    03392 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
    03393 ** returns a different mutex on every call.  But for the static
    03394 ** mutex types, the same mutex is returned on every call that has
    03395 ** the same type number.
    03396 **
    03397 ** The sqlite3_mutex_free() routine deallocates a previously
    03398 ** allocated dynamic mutex.  SQLite is careful to deallocate every
    03399 ** dynamic mutex that it allocates.  The dynamic mutexes must not be in
    03400 ** use when they are deallocated.  Attempting to deallocate a static
    03401 ** mutex results in undefined behavior.  SQLite never deallocates
    03402 ** a static mutex.
    03403 **
    03404 ** The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
    03405 ** to enter a mutex.  If another thread is already within the mutex,
    03406 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
    03407 ** SQLITE_BUSY.  The sqlite3_mutex_try() interface returns SQLITE_OK
    03408 ** upon successful entry.  Mutexes created using SQLITE_MUTEX_RECURSIVE can
    03409 ** be entered multiple times by the same thread.  In such cases the,
    03410 ** mutex must be exited an equal number of times before another thread
    03411 ** can enter.  If the same thread tries to enter any other kind of mutex
    03412 ** more than once, the behavior is undefined.   SQLite will never exhibit
    03413 ** such behavior in its own use of mutexes.
    03414 **
    03415 ** The sqlite3_mutex_leave() routine exits a mutex that was
    03416 ** previously entered by the same thread.  The behavior
    03417 ** is undefined if the mutex is not currently entered by the
    03418 ** calling thread or is not currently allocated.  SQLite will
    03419 ** never do either.
    03420 **
    03421 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
    03422 */
    03423 sqlite3_mutex *sqlite3_mutex_alloc(int);
    03424 void sqlite3_mutex_free(sqlite3_mutex*);
    03425 void sqlite3_mutex_enter(sqlite3_mutex*);
    03426 int sqlite3_mutex_try(sqlite3_mutex*);
    03427 void sqlite3_mutex_leave(sqlite3_mutex*);
    03428
    03429 /*
    03430 ** CAPI3REF: Mutex Verifcation Routines
    03431 **
    03432 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
    03433 ** are intended for use inside assert() statements.  The SQLite core
    03434 ** never uses these routines except inside an assert() and applications
    03435 ** are advised to follow the lead of the core.  The core only
    03436 ** provides implementations for these routines when it is compiled
    03437 ** with the SQLITE_DEBUG flag.  External mutex implementations
    03438 ** are only required to provide these routines if SQLITE_DEBUG is
    03439 ** defined and if NDEBUG is not defined.
    03440 **
    03441 ** These routines should return true if the mutex in their argument
    03442 ** is held or not held, respectively, by the calling thread.
    03443 **
    03444 ** The implementation is not required to provided versions of these
    03445 ** routines that actually work.
    03446 ** If the implementation does not provide working
    03447 ** versions of these routines, it should at least provide stubs
    03448 ** that always return true so that one does not get spurious
    03449 ** assertion failures.
    03450 **
    03451 ** If the argument to sqlite3_mutex_held() is a NULL pointer then
    03452 ** the routine should return 1.  This seems counter-intuitive since
    03453 ** clearly the mutex cannot be held if it does not exist.  But the
    03454 ** the reason the mutex does not exist is because the build is not
    03455 ** using mutexes.  And we do not want the assert() containing the
    03456 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
    03457 ** the appropriate thing to do.  The sqlite3_mutex_notheld()
    03458 ** interface should also return 1 when given a NULL pointer.
    03459 */
    03460 int sqlite3_mutex_held(sqlite3_mutex*);
    03461 int sqlite3_mutex_notheld(sqlite3_mutex*);
    03462
    03463 /*
    03464 ** CAPI3REF: Mutex Types
    03465 **
    03466 ** The [sqlite3_mutex_alloc()] interface takes a single argument
    03467 ** which is one of these integer constants.
    03468 */
    03469 #define SQLITE_MUTEX_FAST             0
    03470 #define SQLITE_MUTEX_RECURSIVE        1
    03471 #define SQLITE_MUTEX_STATIC_MASTER    2
    03472 #define SQLITE_MUTEX_STATIC_MEM       3  /* sqlite3_malloc() */
    03473 #define SQLITE_MUTEX_STATIC_MEM2      4  /* sqlite3_release_memory() */
    03474 #define SQLITE_MUTEX_STATIC_PRNG      5  /* sqlite3_random() */
    03475 #define SQLITE_MUTEX_STATIC_LRU       6  /* lru page list */
    03476
    03477 /*
    03478 ** CAPI3REF: Low-Level Control Of Database Files
    03479 **
    03480 ** The [sqlite3_file_control()] interface makes a direct call to the
    03481 ** xFileControl method for the [sqlite3_io_methods] object associated
    03482 ** with a particular database identified by the second argument.  The
    03483 ** name of the database is the name assigned to the database by the
    03484 ** <a href="lang_attach.html">ATTACH</a> SQL command that opened the
    03485 ** database.  To control the main database file, use the name "main"
    03486 ** or a NULL pointer.  The third and fourth parameters to this routine
    03487 ** are passed directly through to the second and third parameters of
    03488 ** the xFileControl method.  The return value of the xFileControl
    03489 ** method becomes the return value of this routine.
    03490 **
    03491 ** If the second parameter (zDbName) does not match the name of any
    03492 ** open database file, then SQLITE_ERROR is returned.  This error
    03493 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
    03494 ** or [sqlite3_errmsg()].  The underlying xFileControl method might
    03495 ** also return SQLITE_ERROR.  There is no way to distinguish between
    03496 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
    03497 ** xFileControl method.
    03498 **
    03499 ** See also: [SQLITE_FCNTL_LOCKSTATE]
    03500 */
    03501 int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
    03502
    03503 /*
    03504 ** Undo the hack that converts floating point types to integer for
    03505 ** builds on processors without floating point support.
    03506 */
    03507 #ifdef SQLITE_OMIT_FLOATING_POINT
    03508 # undef double
    03509 #endif
    03510
    03511 #ifdef __cplusplus
    03512 }  /* End of the 'extern "C"' block */
    03513 #endif
    03514 #endif