sqlite3.h.svn-base

SQlite 的使用 读库 写库

/* 
** After an SQL query has been compiled with a call to either
** sqlite3_prepare() or sqlite3_prepare16(), then this function must be
** called one or more times to execute the statement.
**
** The return value will be either SQLITE_BUSY, SQLITE_DONE, 
** SQLITE_ROW, SQLITE_ERROR, or SQLITE_MISUSE.
**
** SQLITE_BUSY means that the database engine attempted to open
** a locked database and there is no busy callback registered.
** Call sqlite3_step() again to retry the open.
**
** SQLITE_DONE means that the statement has finished executing
** successfully.  sqlite3_step() should not be called again on this virtual
** machine.
**
** If the SQL statement being executed returns any data, then 
** SQLITE_ROW is returned each time a new row of data is ready
** for processing by the caller. The values may be accessed using
** the sqlite3_column_*() functions described below. sqlite3_step()
** is called again to retrieve the next row of data.
** 
** SQLITE_ERROR means that a run-time error (such as a constraint
** violation) has occurred.  sqlite3_step() should not be called again on
** the VM. More information may be found by calling sqlite3_errmsg().
**
** SQLITE_MISUSE means that the this routine was called inappropriately.
** Perhaps it was called on a virtual machine that had already been
** finalized or on one that had previously returned SQLITE_ERROR or
** SQLITE_DONE.  Or it could be the case the the same database connection
** is being used simulataneously by two or more threads.
*/
int sqlite3_step(sqlite3_stmt*);

/*
** Return the number of values in the current row of the result set.
**
** After a call to sqlite3_step() that returns SQLITE_ROW, this routine
** will return the same value as the sqlite3_column_count() function.
** After sqlite3_step() has returned an SQLITE_DONE, SQLITE_BUSY or
** error code, or before sqlite3_step() has been called on a 
** compiled SQL statement, this routine returns zero.
*/
int sqlite3_data_count(sqlite3_stmt *pStmt);

/*
** Values are stored in the database in one of the following fundamental
** types.
*/
#define SQLITE_INTEGER  1
#define SQLITE_FLOAT    2
/* #define SQLITE_TEXT  3  // See below */
#define SQLITE_BLOB     4
#define SQLITE_NULL     5

/*
** SQLite version 2 defines SQLITE_TEXT differently.  To allow both
** version 2 and version 3 to be included, undefine them both if a
** conflict is seen.  Define SQLITE3_TEXT to be the version 3 value.
*/
#ifdef SQLITE_TEXT
# undef SQLITE_TEXT
#else
# define SQLITE_TEXT     3
#endif
#define SQLITE3_TEXT     3

/*
** The next group of routines returns information about the information
** in a single column of the current result row of a query.  In every
** case the first parameter is a pointer to the SQL statement that is being
** executed (the sqlite_stmt* that was returned from sqlite3_prepare()) and
** the second argument is the index of the column for which information 
** should be returned.  iCol is zero-indexed.  The left-most column as an
** index of 0.
**
** If the SQL statement is not currently point to a valid row, or if the
** the colulmn index is out of range, the result is undefined.
**
** These routines attempt to convert the value where appropriate.  For
** example, if the internal representation is FLOAT and a text result
** is requested, sprintf() is used internally to do the conversion
** automatically.  The following table details the conversions that
** are applied:
**
**    Internal Type    Requested Type     Conversion
**    -------------    --------------    --------------------------
**       NULL             INTEGER         Result is 0
**       NULL             FLOAT           Result is 0.0
**       NULL             TEXT            Result is an empty string
**       NULL             BLOB            Result is a zero-length BLOB
**       INTEGER          FLOAT           Convert from integer to float
**       INTEGER          TEXT            ASCII rendering of the integer
**       INTEGER          BLOB            Same as for INTEGER->TEXT
**       FLOAT            INTEGER         Convert from float to integer
**       FLOAT            TEXT            ASCII rendering of the float
**       FLOAT            BLOB            Same as FLOAT->TEXT
**       TEXT             INTEGER         Use atoi()
**       TEXT             FLOAT           Use atof()
**       TEXT             BLOB            No change
**       BLOB             INTEGER         Convert to TEXT then use atoi()
**       BLOB             FLOAT           Convert to TEXT then use atof()
**       BLOB             TEXT            Add a \000 terminator if needed
**
** The following access routines are provided:
**
** _type()     Return the datatype of the result.  This is one of
**             SQLITE_INTEGER, SQLITE_FLOAT, SQLITE_TEXT, SQLITE_BLOB,
**             or SQLITE_NULL.
** _blob()     Return the value of a BLOB.
** _bytes()    Return the number of bytes in a BLOB value or the number
**             of bytes in a TEXT value represented as UTF-8.  The \000
**             terminator is included in the byte count for TEXT values.
** _bytes16()  Return the number of bytes in a BLOB value or the number
**             of bytes in a TEXT value represented as UTF-16.  The \u0000
**             terminator is included in the byte count for TEXT values.
** _double()   Return a FLOAT value.
** _int()      Return an INTEGER value in the host computer's native
**             integer representation.  This might be either a 32- or 64-bit
**             integer depending on the host.
** _int64()    Return an INTEGER value as a 64-bit signed integer.
** _text()     Return the value as UTF-8 text.
** _text16()   Return the value as UTF-16 text.
*/
const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
double sqlite3_column_double(sqlite3_stmt*, int iCol);
int sqlite3_column_int(sqlite3_stmt*, int iCol);
sqlite_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
int sqlite3_column_type(sqlite3_stmt*, int iCol);
int sqlite3_column_numeric_type(sqlite3_stmt*, int iCol);
sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);

/*
** The sqlite3_finalize() function is called to delete a compiled
** SQL statement obtained by a previous call to sqlite3_prepare()
** or sqlite3_prepare16(). If the statement was executed successfully, or
** not executed at all, then SQLITE_OK is returned. If execution of the
** statement failed then an error code is returned. 
**
** 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 sqlite3_interrupt().)  Incomplete updates may be
** rolled back and transactions cancelled,  depending on the circumstances,
** and the result code returned will be SQLITE_ABORT.
*/
int sqlite3_finalize(sqlite3_stmt *pStmt);

/*
** The sqlite3_reset() function is called to reset a compiled SQL
** statement obtained by a previous call to sqlite3_prepare() or
** sqlite3_prepare16() back to it's initial state, ready to be re-executed.
** Any SQL statement variables that had values bound to them using
** the sqlite3_bind_*() API retain their values.
*/
int sqlite3_reset(sqlite3_stmt *pStmt);

/*
** The following two functions are used to add user functions or aggregates
** implemented in C to the SQL langauge interpreted by SQLite. The
** difference only between the two is that the second parameter, the
** name of the (scalar) function or aggregate, is encoded in UTF-8 for
** sqlite3_create_function() and UTF-16 for sqlite3_create_function16().
**
** The first argument is the database handle that the new function or
** aggregate is to be added to. If a single program uses more than one
** database handle internally, then user functions or aggregates must 
** be added individually to each database handle with which they will be
** used.
**
** The third parameter is the number of arguments that the function or
** aggregate takes. If this parameter is negative, then the function or
** aggregate may take any number of arguments.
**
** The fourth parameter is one of SQLITE_UTF* values defined below,
** indicating the encoding that the function is most likely to handle
** values in.  This does not change the behaviour of the programming
** interface. However, if two versions of the same function are registered
** with different encoding values, SQLite invokes the version likely to
** minimize conversions between text encodings.
**
** The seventh, eighth and ninth parameters, xFunc, xStep and xFinal, are
** pointers to user implemented C functions that implement the user
** function or aggregate. A scalar function requires an implementation of
** the xFunc callback only, NULL pointers should be passed as the xStep
** and xFinal parameters. An aggregate function requires an implementation
** of xStep and xFinal, but NULL should be passed for xFunc. To delete an
** existing user function or aggregate, pass NULL for all three function
** callback. Specifying an inconstent set of callback values, such as an
** xFunc and an xFinal, or an xStep but no xFinal, SQLITE_ERROR is
** returned.
*/
int sqlite3_create_function(
  sqlite3 *,
  const char *zFunctionName,
  int nArg,
  int eTextRep,
  void*,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
);
int sqlite3_create_function16(
  sqlite3*,
  const void *zFunctionName,
  int nArg,
  int eTextRep,
  void*,
  void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
  void (*xStep)(sqlite3_context*,int,sqlite3_value**),
  void (*xFinal)(sqlite3_context*)
);

/*
** This function is deprecated.  Do not use it.  It continues to exist
** so as not to break legacy code.  But new code should avoid using it.
*/
int sqlite3_aggregate_count(sqlite3_context*);

/*
** The next group of routines returns information about parameters to
** a user-defined function.  Function implementations use these routines
** to access their parameters.  These routines are the same as the
** sqlite3_column_* routines except that these routines take a single
** sqlite3_value* pointer instead of an sqlite3_stmt* and an integer
** column number.
*/
const void *sqlite3_value_blob(sqlite3_value*);
int sqlite3_value_bytes(sqlite3_value*);
int sqlite3_value_bytes16(sqlite3_value*);
double sqlite3_value_double(sqlite3_value*);
int sqlite3_value_int(sqlite3_value*);
sqlite_int64 sqlite3_value_int64(sqlite3_value*);
const unsigned char *sqlite3_value_text(sqlite3_value*);
const void *sqlite3_value_text16(sqlite3_value*);
const void *sqlite3_value_text16le(sqlite3_value*);
const void *sqlite3_value_text16be(sqlite3_value*);
int sqlite3_value_type(sqlite3_value*);
int sqlite3_value_numeric_type(sqlite3_value*);

/*
** Aggregate functions use the following routine to allocate
** a structure for storing their state.  The first time this routine
** is called for a particular aggregate, a new structure of size nBytes
** is allocated, zeroed, and returned.  On subsequent calls (for the
** same aggregate instance) the same buffer is returned.  The implementation
** of the aggregate can use the returned buffer to accumulate data.
**
** The buffer allocated is freed automatically by SQLite.
*/
void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);

/*
** The pUserData parameter to the sqlite3_create_function()
** routine used to register user functions is available to
** the implementation of the function using this call.
*/
void *sqlite3_user_data(sqlite3_context*);

/*
** The following two functions may be used by scalar user functions to
** associate meta-data with argument values. If the same value is passed to
** multiple invocations of the user-function during query execution, under
** some circumstances the associated meta-data may be preserved. This may
** be used, for example, to add a regular-expression matching scalar
** function. The compiled version of the regular expression is stored as
** meta-data associated with the SQL value passed as the regular expression
** pattern.
**
** Calling sqlite3_get_auxdata() returns a pointer to the meta data
** associated with the Nth argument value to the current user function
** call, where N is the second parameter. If no meta-data has been set for
** that value, then a NULL pointer is returned.
**
** The sqlite3_set_auxdata() is used to associate meta data with a user
** function argument. The third parameter is a pointer to the meta data
** to be associated with the Nth user function argument value. The fourth
** parameter specifies a 'delete function' that will be called on the meta
** data pointer to release it when it is no longer required. If the delete
** function pointer is NULL, it is not invoked.
**
** In practice, meta-data is preserved between function calls for
** expressions that are constant at compile time. This includes literal
** values and SQL variables.
*/
void *sqlite3_get_auxdata(sqlite3_context*, int);
void sqlite3_set_auxdata(sqlite3_context*, int, void*, void (*)(void*));


/*