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DEFINITIONS
This source file includes following definitions.
- sqlite_get_table_cb
- sqlite_get_table
- sqlite_free_table
/*
** 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 sqlite_get_table() and sqlite_free_table()
** interface routines. These are just wrappers around the main
** interface routine of sqlite_exec().
**
** These routines are in a separate files so that they will not be linked
** if they are not used.
*/
#include <stdlib.h>
#include <string.h>
#include "sqliteInt.h"
/*
** This structure is used to pass data from sqlite_get_table() through
** to the callback function is uses to build the result.
*/
typedef struct TabResult {
char **azResult;
char *zErrMsg;
int nResult;
int nAlloc;
int nRow;
int nColumn;
long nData;
int rc;
} 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 sqlite_get_table_cb(void *pArg, int nCol, char **argv, char **colv){
TabResult *p = (TabResult*)pArg;
int need;
int i;
char *z;
/* 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 + 1;
azNew = realloc( p->azResult, sizeof(char*)*p->nAlloc );
if( azNew==0 ){
p->rc = SQLITE_NOMEM;
return 1;
}
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++){
if( colv[i]==0 ){
z = 0;
}else{
z = malloc( strlen(colv[i])+1 );
if( z==0 ){
p->rc = SQLITE_NOMEM;
return 1;
}
strcpy(z, colv[i]);
}
p->azResult[p->nData++] = z;
}
}else if( p->nColumn!=nCol ){
sqliteSetString(&p->zErrMsg,
"sqlite_get_table() called with two or more incompatible queries",
(char*)0);
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{
z = malloc( strlen(argv[i])+1 );
if( z==0 ){
p->rc = SQLITE_NOMEM;
return 1;
}
strcpy(z, argv[i]);
}
p->azResult[p->nData++] = z;
}
p->nRow++;
}
return 0;
}
/*
** 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 sqlite_free_table() when
** the calling procedure is finished using it.
*/
int sqlite_get_table(
sqlite *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;
if( pazResult==0 ){ return SQLITE_ERROR; }
*pazResult = 0;
if( pnColumn ) *pnColumn = 0;
if( pnRow ) *pnRow = 0;
res.zErrMsg = 0;
res.nResult = 0;
res.nRow = 0;
res.nColumn = 0;
res.nData = 1;
res.nAlloc = 20;
res.rc = SQLITE_OK;
res.azResult = malloc( sizeof(char*)*res.nAlloc );
if( res.azResult==0 ){
return SQLITE_NOMEM;
}
res.azResult[0] = 0;
rc = sqlite_exec(db, zSql, sqlite_get_table_cb, &res, pzErrMsg);
if( res.azResult ){
res.azResult[0] = (char*)res.nData;
}
if( rc==SQLITE_ABORT ){
sqlite_free_table(&res.azResult[1]);
if( res.zErrMsg ){
if( pzErrMsg ){
free(*pzErrMsg);
*pzErrMsg = res.zErrMsg;
sqliteStrRealloc(pzErrMsg);
}else{
sqliteFree(res.zErrMsg);
}
}
return res.rc;
}
sqliteFree(res.zErrMsg);
if( rc!=SQLITE_OK ){
sqlite_free_table(&res.azResult[1]);
return rc;
}
if( res.nAlloc>res.nData ){
char **azNew;
azNew = realloc( res.azResult, sizeof(char*)*(res.nData+1) );
if( azNew==0 ){
sqlite_free_table(&res.azResult[1]);
return SQLITE_NOMEM;
}
res.nAlloc = res.nData+1;
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 sqlite_get_table() malloced.
*/
void sqlite_free_table(
char **azResult /* Result returned from from sqlite_get_table() */
){
if( azResult ){
int i, n;
azResult--;
if( azResult==0 ) return;
n = (int)(long)azResult[0];
for(i=1; i<n; i++){ if( azResult[i] ) free(azResult[i]); }
free(azResult);
}
}