/*

** 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 */