NSPredicate for to-many relationship, where a relationship (NSSet) must contain Entities defined in an NSArray

Question

Given the following Core Data Model:

-> : to-one releationship  
->>: to-many relationship

Entity A ->> Entity B 
Entity B -> A // each B belo         


        

Answer 1

Does

[NSPredicate predicateWithFormat:@"A==%@ AND (ALL %@ IN Bs)", Ax, myArray];

do what you expect? I am not sure (and away from my OS X box) whether this predicate is translatable to SQL for the Core Data SQLite engine. You may need a SUBQUERY expression:

[NSPredicate preidcateWithFormat:@"A==%@ and SUBQUERY(Bs, $x, $x IN %@).@count == %d", Ax, myArray, myArray.count];

This assumes that the items in myArray are unique.