CustomersViewController.m

- (void)reloadFetchedResultsController {
    
    [NSFetchedResultsController deleteCacheWithName:@"Customers"];
    
    if (_request == nil) {
        _request = [[NSFetchRequest alloc] initWithEntityName:@"Customer"];
    }
    
    NSPredicate *predicate = [NSPredicate predicateWithValue:YES];
    
    if (_departament) {
        
        NSPredicate *query = [NSPredicate predicateWithFormat:@"departament = %@", _departament];
        
        predicate          = [NSCompoundPredicate andPredicateWithSubpredicates:@[ predicate, query ]];
    }
    
    if (_searchBar.text.length) {
        
        NSPredicate *pred1 = [NSPredicate predicateWithFormat:@"lastname contains[cd] %@", _searchBar.text];
        NSPredicate *pred2 = [NSPredicate predicateWithFormat:@"firstname contains[cd] %@", _searchBar.text];
        
        NSPredicate *query = [NSCompoundPredicate orPredicateWithSubpredicates:@[pred1,pred2]];
        
        predicate = [NSCompoundPredicate andPredicateWithSubpredicates:@[ predicate, query ]];
    }
    
    _request.predicate = predicate;
    
    NSSortDescriptor *lastnameSort = [NSSortDescriptor sortDescriptorWithKey:_sortByKey
                                                                   ascending:YES];
    
    [_request setSortDescriptors:@[lastnameSort]];
    
    if (_resultsCtl == nil) {
        _resultsCtl = [[NSFetchedResultsController alloc] initWithFetchRequest:_request
                                                          managedObjectContext:self.moc
                                                            sectionNameKeyPath:@"sortLetter"
                                                                     cacheName:@"Customers"];
        _resultsCtl.delegate = self;
    }
    
    NSError *error = nil;
    
    [_resultsCtl performFetch:&error];
    
    if (error) {
        NSLog(@"performFetch error = %@", error);
    }
}