Core data : NSFetchedResultsController - ios

Question

This is my datamodel
In my TableView, I want to display first and city
The following is my code where I fetch them. I'm getting the first data but not the city:
-(NSFetchedResultsController *)fetchedResultsController
{
if(fetchedResultsController != nil)
{
return fetchedResultsController;
}
NSManagedObjectContext *context = [self managedObjectContext];
NSFetchRequest *request = [[NSFetchRequest alloc] init];
NSEntityDescription *entityPerson = [NSEntityDescription entityForName:#"Person" inManagedObjectContext:context];
[request setEntity:entityPerson];
NSSortDescriptor *sortName = [[NSSortDescriptor alloc] initWithKey:#"first" ascending:YES];
NSSortDescriptor *sortAddress = [[NSSortDescriptor alloc] initWithKey:#"address.city" ascending:NO];
request.sortDescriptors = #[sortAddress, sortName];
[request setFetchBatchSize:50];
NSFetchedResultsController *fetchedResults = [[NSFetchedResultsController alloc] initWithFetchRequest:request managedObjectContext:context sectionNameKeyPath:nil cacheName:nil];
fetchedResultsController = fetchedResults;
fetchedResultsController.delegate = self;
return fetchedResultsController;
}
This is where i fetch the results and following is where i try to display the fetched results
-(UITableViewCell *)tableView:(UITableView *)tableView cellForRowAtIndexPath:(NSIndexPath *)indexPath
{
static NSString *CellIdentifier = #"TableCell";
TableCell *cell = (TableCell *)[tableView dequeueReusableCellWithIdentifier:CellIdentifier forIndexPath:indexPath];
if (cell == nil)
{
cell = [[TableCell alloc] initWithStyle:UITableViewCellStyleDefault
reuseIdentifier:CellIdentifier];
}
[self configureCell:cell atIndexPath:indexPath];
return cell;
}
-(void)configureCell:(TableCell *)cell atIndexPath:(NSIndexPath *)indexPath
{
NSManagedObject *obj = [fetchedResultsController objectAtIndexPath:indexPath];
// cell.lblName.text = #"";
[cell.lblName setText:[obj valueForKey:#"first"]];
// cell.lblCity.text = #"";
[cell.lblCity setText:[obj valueForKey:#"city"]];
}

Answer 1

Your fetched results controller is configured to return Person objects, so you need to reference the properties of the relationship indirectly:
[cell.lblCity setText:[obj valueForKeyPath:#"address.city"]];
or if you have created a subclass of NSManagedObject, say as Person, you can amend your code to:
Person *obj = [fetchedResultsController objectAtIndexPath:indexPath];
cell.lblName.text = obj.first;
cell.lblCity.text = obj.address.city;