sqlite.h

sqlite数据库管理系统开放源码

#define SQLITE_DROP_TEMP_TRIGGER    14   /* Trigger Name    Table Name      */
#define SQLITE_DROP_TEMP_VIEW       15   /* View Name       NULL            */
#define SQLITE_DROP_TRIGGER         16   /* Trigger Name    Table Name      */
#define SQLITE_DROP_VIEW            17   /* View Name       NULL            */
#define SQLITE_INSERT               18   /* Table Name      NULL            */
#define SQLITE_PRAGMA               19   /* Pragma Name     1st arg or NULL */
#define SQLITE_READ                 20   /* Table Name      Column Name     */
#define SQLITE_SELECT               21   /* NULL            NULL            */
#define SQLITE_TRANSACTION          22   /* NULL            NULL            */
#define SQLITE_UPDATE               23   /* Table Name      Column Name     */
#define SQLITE_ATTACH               24   /* Filename        NULL            */
#define SQLITE_DETACH               25   /* Database Name   NULL            */


/*
** The return value of the authorization function should be one of the
** following constants:
*/
/* #define SQLITE_OK  0   // Allow access (This is actually defined above) */
#define SQLITE_DENY   1   /* Abort the SQL statement with an error */
#define SQLITE_IGNORE 2   /* Don't allow access, but don't generate an error */

/*
** Register a function that is called at every invocation of sqlite_exec()
** or sqlite_compile().  This function can be used (for example) to generate
** a log file of all SQL executed against a database.
*/
void *sqlite_trace(sqlite*, void(*xTrace)(void*,const char*), void*);

/*** The Callback-Free API
** 
** The following routines implement a new way to access SQLite that does not
** involve the use of callbacks.
**
** An sqlite_vm is an opaque object that represents a single SQL statement
** that is ready to be executed.
*/
typedef struct sqlite_vm sqlite_vm;

/*
** To execute an SQLite query without the use of callbacks, you first have
** to compile the SQL using this routine.  The 1st parameter "db" is a pointer
** to an sqlite object obtained from sqlite_open().  The 2nd parameter
** "zSql" is the text of the SQL to be compiled.   The remaining parameters
** are all outputs.
**
** *pzTail is made to point to the first character past the end of the first
** SQL statement in zSql.  This routine only compiles the first statement
** in zSql, so *pzTail is left pointing to what remains uncompiled.
**
** *ppVm is left pointing to a "virtual machine" that can be used to execute
** the compiled statement.  Or if there is an error, *ppVm may be set to NULL.
** If the input text contained no SQL (if the input is and empty string or
** a comment) then *ppVm is set to NULL.
**
** If any errors are detected during compilation, an error message is written
** into space obtained from malloc() and *pzErrMsg is made to point to that
** error message.  The calling routine is responsible for freeing the text
** of this message when it has finished with it.  Use sqlite_freemem() to
** free the message.  pzErrMsg may be NULL in which case no error message
** will be generated.
**
** On success, SQLITE_OK is returned.  Otherwise and error code is returned.
*/
int sqlite_compile(
  sqlite *db,                   /* The open database */
  const char *zSql,             /* SQL statement to be compiled */
  const char **pzTail,          /* OUT: uncompiled tail of zSql */
  sqlite_vm **ppVm,             /* OUT: the virtual machine to execute zSql */
  char **pzErrmsg               /* OUT: Error message. */
);

/*
** After an SQL statement has been compiled, it is handed to this routine
** to be executed.  This routine executes the statement as far as it can
** go then returns.  The return value will be one of SQLITE_DONE,
** SQLITE_ERROR, SQLITE_BUSY, SQLITE_ROW, or SQLITE_MISUSE.
**
** SQLITE_DONE means that the execute of the SQL statement is complete
** an no errors have occurred.  sqlite_step() should not be called again
** for the same virtual machine.  *pN is set to the number of columns in
** the result set and *pazColName is set to an array of strings that
** describe the column names and datatypes.  The name of the i-th column
** is (*pazColName)[i] and the datatype of the i-th column is
** (*pazColName)[i+*pN].  *pazValue is set to NULL.
**
** SQLITE_ERROR means that the virtual machine encountered a run-time
** error.  sqlite_step() should not be called again for the same
** virtual machine.  *pN is set to 0 and *pazColName and *pazValue are set
** to NULL.  Use sqlite_finalize() to obtain the specific error code
** and the error message text for the error.
**
** SQLITE_BUSY means that an attempt to open the database failed because
** another thread or process is holding a lock.  The calling routine
** can try again to open the database by calling sqlite_step() again.
** The return code will only be SQLITE_BUSY if no busy handler is registered
** using the sqlite_busy_handler() or sqlite_busy_timeout() routines.  If
** a busy handler callback has been registered but returns 0, then this
** routine will return SQLITE_ERROR and sqltie_finalize() will return
** SQLITE_BUSY when it is called.
**
** SQLITE_ROW means that a single row of the result is now available.
** The data is contained in *pazValue.  The value of the i-th column is
** (*azValue)[i].  *pN and *pazColName are set as described in SQLITE_DONE.
** Invoke sqlite_step() again to advance to the next row.
**
** SQLITE_MISUSE is returned if sqlite_step() is called incorrectly.
** For example, if you call sqlite_step() after the virtual machine
** has halted (after a prior call to sqlite_step() has returned SQLITE_DONE)
** or if you call sqlite_step() with an incorrectly initialized virtual
** machine or a virtual machine that has been deleted or that is associated
** with an sqlite structure that has been closed.
*/
int sqlite_step(
  sqlite_vm *pVm,              /* The virtual machine to execute */
  int *pN,                     /* OUT: Number of columns in result */
  const char ***pazValue,      /* OUT: Column data */
  const char ***pazColName     /* OUT: Column names and datatypes */
);

/*
** This routine is called to delete a virtual machine after it has finished
** executing.  The return value is the result code.  SQLITE_OK is returned
** if the statement executed successfully and some other value is returned if
** there was any kind of error.  If an error occurred and pzErrMsg is not
** NULL, then an error message is written into memory obtained from malloc()
** and *pzErrMsg is made to point to that error message.  The calling routine
** should use sqlite_freemem() to delete this message when it has finished
** with it.
**
** This routine can be called at any point during the execution of the
** virtual machine.  If the virtual machine has not completed execution
** when this routine is called, that is like encountering an error or
** an interrupt.  (See sqlite_interrupt().)  Incomplete updates may be
** rolled back and transactions cancelled,  depending on the circumstances,
** and the result code returned will be SQLITE_ABORT.
*/
int sqlite_finalize(sqlite_vm*, char **pzErrMsg);

/*
** This routine deletes the virtual machine, writes any error message to
** *pzErrMsg and returns an SQLite return code in the same way as the
** sqlite_finalize() function.
**
** Additionally, if ppVm is not NULL, *ppVm is left pointing to a new virtual
** machine loaded with the compiled version of the original query ready for
** execution.
**
** If sqlite_reset() returns SQLITE_SCHEMA, then *ppVm is set to NULL.
**
******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
*/
int sqlite_reset(sqlite_vm*, char **pzErrMsg);

/*
** If the SQL that was handed to sqlite_compile contains variables that
** are represeted in the SQL text by a question mark ('?').  This routine
** is used to assign values to those variables.
**
** The first parameter is a virtual machine obtained from sqlite_compile().
** The 2nd "idx" parameter determines which variable in the SQL statement
** to bind the value to.  The left most '?' is 1.  The 3rd parameter is
** the value to assign to that variable.  The 4th parameter is the number
** of bytes in the value, including the terminating \000 for strings.
** Finally, the 5th "copy" parameter is TRUE if SQLite should make its
** own private copy of this value, or false if the space that the 3rd
** parameter points to will be unchanging and can be used directly by
** SQLite.
**
** Unbound variables are treated as having a value of NULL.  To explicitly
** set a variable to NULL, call this routine with the 3rd parameter as a
** NULL pointer.
**
** If the 4th "len" parameter is -1, then strlen() is used to find the
** length.
**
** This routine can only be called immediately after sqlite_compile()
** or sqlite_reset() and before any calls to sqlite_step().
**
******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
*/
int sqlite_bind(sqlite_vm*, int idx, const char *value, int len, int copy);

/*
** This routine configures a callback function - the progress callback - that
** is invoked periodically during long running calls to sqlite_exec(),
** sqlite_step() and sqlite_get_table(). An example use for this API is to keep
** a GUI updated during a large query.
**
** The progress callback is invoked once for every N virtual machine opcodes,
** where N is the second argument to this function. The progress callback
** itself is identified by the third argument to this function. The fourth
** argument to this function is a void pointer passed to the progress callback
** function each time it is invoked.
**
** If a call to sqlite_exec(), sqlite_step() or sqlite_get_table() results 
** in less than N opcodes being executed, then the progress callback is not
** invoked.
** 
** Calling this routine overwrites any previously installed progress callback.
** To remove the progress callback altogether, pass NULL as the third
** argument to this function.
**
** If the progress callback returns a result other than 0, then the current 
** query is immediately terminated and any database changes rolled back. If the
** query was part of a larger transaction, then the transaction is not rolled
** back and remains active. The sqlite_exec() call returns SQLITE_ABORT. 
**
******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
*/
void sqlite_progress_handler(sqlite*, int, int(*)(void*), void*);

/*
** Register a callback function to be invoked whenever a new transaction
** is committed.  The pArg argument is passed through to the callback.
** callback.  If the callback function returns non-zero, then the commit
** is converted into a rollback.
**
** If another function was previously registered, its pArg value is returned.
** Otherwise NULL is returned.
**
** Registering a NULL function disables the callback.
**
******* THIS IS AN EXPERIMENTAL API AND IS SUBJECT TO CHANGE ******
*/
void *sqlite_commit_hook(sqlite*, int(*)(void*), void*);

/*
** Open an encrypted SQLite database.  If pKey==0 or nKey==0, this routine
** is the same as sqlite_open().
**
** The code to implement this API is not available in the public release
** of SQLite.
*/
sqlite *sqlite_open_encrypted(
  const char *zFilename,   /* Name of the encrypted database */
  const void *pKey,        /* Pointer to the key */
  int nKey,                /* Number of bytes in the key */
  int *pErrcode,           /* Write error code here */
  char **pzErrmsg          /* Write error message here */
);

/*
** Change the key on an open database.  If the current database is not
** encrypted, this routine will encrypt it.  If pNew==0 or nNew==0, the
** database is decrypted.
**
** The code to implement this API is not available in the public release
** of SQLite.
*/
int sqlite_rekey(
  sqlite *db,                    /* Database to be rekeyed */
  const void *pKey, int nKey     /* The new key */
);

/*
** Encode a binary buffer "in" of size n bytes so that it contains
** no instances of characters '\'' or '\000'.  The output is 
** null-terminated and can be used as a string value in an INSERT
** or UPDATE statement.  Use sqlite_decode_binary() to convert the
** string back into its original binary.
**
** The result is written into a preallocated output buffer "out".
** "out" must be able to hold at least 2 +(257*n)/254 bytes.
** In other words, the output will be expanded by as much as 3
** bytes for every 254 bytes of input plus 2 bytes of fixed overhead.
** (This is approximately 2 + 1.0118*n or about a 1.2% size increase.)
**
** The return value is the number of characters in the encoded
** string, excluding the "\000" terminator.
**
** If out==NULL then no output is generated but the routine still returns
** the number of characters that would have been generated if out had
** not been NULL.
*/
int sqlite_encode_binary(const unsigned char *in, int n, unsigned char *out);

/*
** Decode the string "in" into binary data and write it into "out".
** This routine reverses the encoding created by sqlite_encode_binary().
** The output will always be a few bytes less than the input.  The number
** of bytes of output is returned.  If the input is not a well-formed
** encoding, -1 is returned.
**
** The "in" and "out" parameters may point to the same buffer in order
** to decode a string in place.
*/
int sqlite_decode_binary(const unsigned char *in, unsigned char *out);

#ifdef __cplusplus
}  /* End of the 'extern "C"' block */
#endif

#endif /* _SQLITE_H_ */