NSSortDescriptor - Sort descriptor based on another array

Question

I hava a core data application. And I want to fetch one kind of object, User. User have the property userId.

I have another a

Answer 1

Use this idea which i use to sort message id if it is added to DB

NSSortDescriptor *sortDescriptor = [[NSSortDescriptor alloc] initWithKey:@"message_id" ascending:NO selector:@selector(localizedStandardCompare:)];
NSArray *sortDescriptors = [[NSArray alloc] initWithObjects:sortDescriptor, nil];
    [request setSortDescriptors:sortDescriptors];
    request.returnsObjectsAsFaults=NO;
 NSError *error = nil;
    NSArray *results = [managedObjectContext executeFetchRequest:request error:&error];