Question

I am using this code to delete row from Sqlite3 Database,but it’s not working,insert,update,select query are working fine, but the delete statement is not working in my code

 -(void)delete{

        str=title.text;
        sqlite3_stmt *selectstmt;
        if (sqlite3_open([path UTF8String], &database) == SQLITE_OK) {
            NSString *deleteSQL = [NSString stringWithFormat: @"delete from ToDo where title=\"%@\"",str];
            NSLog(@"%@",deleteSQL);
            const char *sql = [deleteSQL UTF8String];
            sqlite3_prepare_v2(database,sql, -1, &selectstmt, NULL); 
            if(sqlite3_prepare_v2(database, sql, -1, &selectstmt, NULL) == SQLITE_OK) 
               NSLog(@"success");
            else
              NSAssert1(0, @"Error while creating delete statement. '%s'", sqlite3_errmsg(database));            
            }
            sqlite3_finalize(selectstmt);
            sqlite3_close(database);
        }

What am I doing wrong?

Answer 1

you can delete particular recored from sqlite database using below code:-

NSDictionary *d =(NSDictionary *) [YourMutableArray objectAtIndex:0];
NSArray *path = NSSearchPathForDirectoriesInDomains(NSDocumentDirectory, NSUserDomainMask, YES);
NSString *documentsDir = [path objectAtIndex:0];
NSString *dbPath =[documentsDir stringByAppendingPathComponent:@"db.sqlite"];
sqlite3_open([dbPath UTF8String], &database);

if(deleteStmt == nil) 
{

    NSString *deleteStatementNS = [NSString stringWithFormat:
                                   @"delete from tbl_postoffice where type = '%@'",
                                   urusniqIDentifire];
    const char *sql = [deleteStatementNS UTF8String];

    //const char *sql ="delete from tbl_todo where type = yourDbfildeRecored";
    if(sqlite3_prepare_v2(database, sql, -1, &deleteStmt, NULL) != SQLITE_OK)
        NSAssert1(0, @"Error while creating delete statement. '%s'", sqlite3_errmsg(database));
}

//When binding parameters, index starts from 1 and not zero.
sqlite3_bind_text(deleteStmt, 1, [[d valueForKey:@"type"] UTF8String], -1, SQLITE_TRANSIENT);
if (SQLITE_DONE != sqlite3_step(deleteStmt)) 
    NSAssert1(0, @"Error while deleting. '%s'", sqlite3_errmsg(database));

sqlite3_reset(deleteStmt);

hope its Helps for you