Question

Suppose i have a one to many relationship between two model entities Entity One and Entity Many, and Entity One has a name field,

Entity One (1) — (m) Entity Many

I want to check if an Entity One exist with name equal to "one" and has associated Entity Many records. Can i perform this check using countForFetchRequest: method? How? I’m not very good very predicates.

Answer 1

Ended up doing this, and seems to be working:

NSFetchRequest *fetchRequest = [[NSFetchRequest alloc] init];
fetchRequest.entity = [NSEntityDescription entityForName:@"EntityA" inManagedObjectContext:context];
fetchRequest.predicate = [NSPredicate predicateWithFormat:@"name == %@ AND relationshipRecords.@count != 0", aName];

NSError *error = nil;
NSUInteger numberOfRecords = [context countForFetchRequest:fetchRequest error:&error];

[fetchRequest release];