/*
** 2001 September 15
**
** The author disclaims copyright to this source code. In place of
** a legal notice, here is a blessing:
**
** May you do good and not evil.
** May you find forgiveness for yourself and forgive others.
** May you share freely, never taking more than you give.
**
*************************************************************************
** This file contains the sqlite3_get_table() and sqlite3_free_table()
** interface routines. These are just wrappers around the main
** interface routine of sqlite3_exec().
**
** These routines are in a separate files so that they will not be linked
** if they are not used.
*/
#include "sqliteInt.h"
#include <stdlib.h>
#include <string.h>
#ifndef SQLITE_OMIT_GET_TABLE
/*
** This structure is used to pass data from sqlite3_get_table() through
** to the callback function is uses to build the result.
*/
typedef struct TabResult {
char **azResult; /* Accumulated output */
char *zErrMsg; /* Error message text, if an error occurs */
int nAlloc; /* Slots allocated for azResult[] */
int nRow; /* Number of rows in the result */
int nColumn; /* Number of columns in the result */
int nData; /* Slots used in azResult[]. (nRow+1)*nColumn */
int rc; /* Return code from sqlite3_exec() */
} TabResult;
/*
** This routine is called once for each row in the result table. Its job
** is to fill in the TabResult structure appropriately, allocating new
** memory as necessary.
*/
static int sqlite3_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
TabResult *p = (TabResult*)pArg; /* Result accumulator */
int need; /* Slots needed in p->azResult[] */
int i; /* Loop counter */
char *z; /* A single column of result */
/* Make sure there is enough space in p->azResult to hold everything
** we need to remember from this invocation of the callback.
*/
if( p->nRow==0 && argv!=0 ){
need = nCol*2;
}else{
need = nCol;
}
if( p->nData + need > p->nAlloc ){
char **azNew;
p->nAlloc = p->nAlloc*2 + need;
azNew = sqlite3_realloc( p->azResult, sizeof(char*)*p->nAlloc );
if( azNew==0 ) goto malloc_failed;
p->azResult = azNew;
}
/* If this is the first row, then generate an extra row containing
** the names of all columns.
*/
if( p->nRow==0 ){
p->nColumn = nCol;
for(i=0; i<nCol; i++){
z = sqlite3_mprintf("%s", colv[i]);
if( z==0 ) goto malloc_failed;
p->azResult[p->nData++] = z;
}
}else if( p->nColumn!=nCol ){
sqlite3_free(p->zErrMsg);
p->zErrMsg = sqlite3_mprintf(
"sqlite3_get_table() called with two or more incompatible queries"
);
p->rc = SQLITE_ERROR;
return 1;
}
/* Copy over the row data
*/
if( argv!=0 ){
for(i=0; i<nCol; i++){
if( argv[i]==0 ){
z = 0;
}else{
int n = sqlite3Strlen30(argv[i])+1;
z = sqlite3_malloc( n );
if( z==0 ) goto malloc_failed;
memcpy(z, argv[i], n);
}
p->azResult[p->nData++] = z;
}
p->nRow++;
}
return 0;
malloc_failed:
p->rc = SQLITE_NOMEM;
return 1;
}
/*
** Query the database. But instead of invoking a callback for each row,
** malloc() for space to hold the result and return the entire results
** at the conclusion of the call.
**
** The result that is written to ***pazResult is held in memory obtained
** from malloc(). But the caller cannot free this memory directly.
** Instead, the entire table should be passed to sqlite3_free_table() when
** the calling procedure is finished using it.
*/
int sqlite3_get_table(
sqlite3 *db, /* The database on which the SQL executes */
const char *zSql, /* The SQL to be executed */
char ***pazResult, /* Write the result table here */
int *pnRow, /* Write the number of rows in the result here */
int *pnColumn, /* Write the number of columns of result here */
char **pzErrMsg /* Write error messages here */
){
int rc;
TabResult res;
*pazResult = 0;
if( pnColumn ) *pnColumn = 0;
if( pnRow ) *pnRow = 0;
if( pzErrMsg ) *pzErrMsg = 0;
res.zErrMsg = 0;
res.nRow = 0;
res.nColumn = 0;
res.nData = 1;
res.nAlloc = 20;
res.rc = SQLITE_OK;
res.azResult = sqlite3_malloc(sizeof(char*)*res.nAlloc );
if( res.azResult==0 ){
db->errCode = SQLITE_NOMEM;
return SQLITE_NOMEM;
}
res.azResult[0] = 0;
rc = sqlite3_exec(db, zSql, sqlite3_get_table_cb, &res, pzErrMsg);
assert( sizeof(res.azResult[0])>= sizeof(res.nData) );
res.azResult[0] = SQLITE_INT_TO_PTR(res.nData);
if( (rc&0xff)==SQLITE_ABORT ){
sqlite3_free_table(&res.azResult[1]);
if( res.zErrMsg ){
if( pzErrMsg ){
sqlite3_free(*pzErrMsg);
*pzErrMsg = sqlite3_mprintf("%s",res.zErrMsg);
}
sqlite3_free(res.zErrMsg);
}
db->errCode = res.rc; /* Assume 32-bit assignment is atomic */
return res.rc;
}
sqlite3_free(res.zErrMsg);
if( rc!=SQLITE_OK ){
sqlite3_free_table(&res.azResult[1]);
return rc;
}
if( res.nAlloc>res.nData ){
char **azNew;
azNew = sqlite3_realloc( res.azResult, sizeof(char*)*res.nData );
if( azNew==0 ){
sqlite3_free_table(&res.azResult[1]);
db->errCode = SQLITE_NOMEM;
return SQLITE_NOMEM;
}
res.azResult = azNew;
}
*pazResult = &res.azResult[1];
if( pnColumn ) *pnColumn = res.nColumn;
if( pnRow ) *pnRow = res.nRow;
return rc;
}
/*
** This routine frees the space the sqlite3_get_table() malloced.
*/
void sqlite3_free_table(
char **azResult /* Result returned from from sqlite3_get_table() */
){
if( azResult ){
int i, n;
azResult--;
assert( azResult!=0 );
n = SQLITE_PTR_TO_INT(azResult[0]);
for(i=1; i<n; i++){ if( azResult[i] ) sqlite3_free(azResult[i]); }
sqlite3_free(azResult);
}
}
#endif /* SQLITE_OMIT_GET_TABLE */