diff options
Diffstat (limited to 'src/table.c')
| -rw-r--r-- | src/table.c | 198 |
1 files changed, 198 insertions, 0 deletions
diff --git a/src/table.c b/src/table.c new file mode 100644 index 0000000..db60a82 --- /dev/null +++ b/src/table.c @@ -0,0 +1,198 @@ +/* +** 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" + +#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 */ + u32 nAlloc; /* Slots allocated for azResult[] */ + u32 nRow; /* Number of rows in the result */ + u32 nColumn; /* Number of columns in the result */ + u32 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 = sqlite3Realloc( 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( (int)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_malloc64( 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_BKPT; + 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; + +#ifdef SQLITE_ENABLE_API_ARMOR + if( !sqlite3SafetyCheckOk(db) || pazResult==0 ) return SQLITE_MISUSE_BKPT; +#endif + *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_malloc64(sizeof(char*)*res.nAlloc ); + if( res.azResult==0 ){ + db->errCode = SQLITE_NOMEM; + return SQLITE_NOMEM_BKPT; + } + 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 = sqlite3Realloc( res.azResult, sizeof(char*)*res.nData ); + if( azNew==0 ){ + sqlite3_free_table(&res.azResult[1]); + db->errCode = SQLITE_NOMEM; + return SQLITE_NOMEM_BKPT; + } + 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 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 */ |