How to get at a relationship items properties in Core Data?

Question

Say you have a Core Data object called Workshop. It has a to-many relationship to a Student object.

How would I create an NSArray of the students within the Workshop?

Answer 1

These relationships are normally declared as an NSSet in your NSManagedObject subclass, like this:

@property (retain) NSSet* students;

And there's also some special accessor methods:

- (void)addStudentsObject:(NSManagedObject *)value;
- (void)removeStudentsObject:(NSManagedObject *)value;
- (void)addStudents:(NSSet *)value;
- (void)removeStudents:(NSSet *)value;

NSSets are similar to NSArrays, but they are not ordered, since Core Data does not guarantee a special sort order for managed objects.