Question

I am working with core data app and my query is that I have a child and parent relationship with the parent relationship having inverse relationship with the child and in the parent entity with To many relationship checked,

So now my query is that I want to access the name of the parent lets say mother name by just giving the child name so i am using predicate for this here’s a view at my code

-(void)retrieveviaPredicate
{
    NSFetchRequest *fetchReq = [[NSFetchRequest alloc]init];
    [fetchReq setEntity:[NSEntityDescription entityForName:@"Child" 
                                    inManagedObjectContext:self.managedObjectContext]];

    NSPredicate *pred = [NSPredicate predicateWithFormat:@"Childname=='ravi'"];
    [fetchReq setPredicate:pred];
    NSArray *t = [self.managedObjectContext executeFetchRequest:fetchReq error:nil];

    for(Child *p in t)
    {
        NSLog(@"%@",p.Childname);

        for(Parent *p1 in p.childToParent)
        {
        NSLog(@"Mother name is %@",p1.MotherName);
        }
    }       
}

In the above code I am getting a warning which says that

warning:  NSManagedObject' may not respond to '-countByEnumeratingWithState:objects:count:

and when I run the app the app goes south, could you please help me out on this

Thanks and Regards

Radix

Answer 1

Check if childToParent is a to-many relationship. I guess it’s not.

---

the for loop would only work if it would be a to-many relationship:

for(Parent *p1 in p.childToParent)

EDIT:

what happens if you replace

for(Parent *p1 in p.childToParent)
{
    NSLog(@"Mother name is %@",p1.MotherName);
}

with

NSLog(@"Mother name is %@",p.childToParent.MotherName);