NSFetchedResultsController with many NSSortDescriptor

Question

in my app I am sorting an entity using only one NSSortDescriptor, but now I need to filter the data for 4 different attributes. This is the code for the current sorting, the result are all records from the entity sorted by the attribute 'displayOrder', but I need to filter the records by four other attributes(year,month,day,group), all of them integer32 except group which is string :

- (NSFetchedResultsController *)fetchedResultsController
{
  if (fetchedResultsController) return fetchedResultsController;

  NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
  NSEntityDescription *entity = 
               [NSEntityDescription entityForName:@"FavoriteThing" 
                           inManagedObjectContext:managedObjectContext];

  [fetchRequest setEntity:entity];

  NSSortDescriptor *sortDescriptor = 
              [[NSSortDescriptor alloc] initWithKey:@"displayOrder" 
                                          ascending:YES];

  NSArray *sortDescriptors = [[NSArray alloc] 
                              initWithObjects:sortDescriptor, nil];  
  [fetchRequest setSortDescriptors:sortDescriptors];

  NSFetchedResultsController *aFetchedResultsController = 
              [[NSFetchedResultsController alloc] initWithFetchRequest:fetchRequest 
                                                  managedObjectContext:managedObjectContext
                                                    sectionNameKeyPath:nil cacheName:@"ThingsCache"];
  aFetchedResultsController.delegate = self;
  [self setFetchedResultsController:aFetchedResultsController];

  [aFetchedResultsController release];
  [fetchRequest release];
  [sortDescriptor release];
  [sortDescriptors release];

  return fetchedResultsController;
}    

---

I have tried adding a predicate:

NSNumber *yearSearched = 1965;
NSPredicate *yearPredicate = [NSPredicate predicateWithFormat:@"todoYear = %@", yearSearched];

[fetchRequest setPredicate:yearPredicate];

But after running the app there is an error EXC_BAD_ACCESS at the line NSPredicate *yearPredicate = [NSPredicate predicateWithFormat:@"todoYear = %@", yearSearched];

Where the attribute 'todoYear' is from type Integer32

Answer 1

Your NSNumber creation is wrong (you're just setting the pointer to an integer). It should be:

NSNumber *yearSearched = @1965;
NSPredicate *yearPredicate = [NSPredicate predicateWithFormat:@"todoYear = %@", yearSearched];

[fetchRequest setPredicate:yearPredicate];