SQLite Database not working correctly

I'm trying to save some data in an SQLite database in my iOS app. I'm doing this with the method below:

NSString *query = [NSString stringWithFormat:@"INSERT INTO categories VALUES ('%@', '%@', '%@', null, %d)", categoryName, @"test", @"test", 33];

NSLog(@"Query is: %@", query);

[[AFSQLManager sharedManager]performQuery:query withBlock:^(NSArray *row, NSError *error, BOOL finished) {

    if (!error) {

        if (!finished) {
            NSLog(@"No success");
        } else {
            NSLog(@"Succeeded");
        }
     } else {

         UIAlertView *alertView = [[UIAlertView alloc]initWithTitle:@"Oops" message:error.description delegate:self cancelButtonTitle:@"OK" otherButtonTitles:nil];
                    [alertView show];
     }
}];

As you can see, I'm using AFSQLManager for executing the queries (you can find it here http://ift.tt/1eEl5KR). The method above logs 'succeeded', but when I pull some data from the database, I get no results. My best guess is that it's a problem with the SQLite database....any idea what I'm doing wrong?