使用来自管理对象的集合作为获取结果控制器的数据

name (string)
orderId (int)
orderBy (string, a key path indicating what to order the table with)
dateCreated (date)
items (a relationship pointing to the items for the next table)

NSPredicate *resultsPredicate = [NSPredicate predicateWithFormat:@\"parent == %@\", parentObject];
[fetchRequest setPredicate:resultsPredicate];

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] 
    initWithKey:[parentObject valueForKey:@\"orderBy\"] ascending:YES];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
[fetchRequest setSortDescriptors:sortDescriptors];