Core Data inheritance and relationship

I have a following data model:

Entity User, which inherits from entity Contact.

Contact has one-to-one relationship with an entity ContactInfo.

User has one-to-many relationship to Contact.

ContactInfo has a reverse relationship to Contact and Contact in its turn has a reverse relationship to User.

I'm creating a ContactInfo object for User:

        ContactInfo *moInfo = [self createContactInfoManagedObject];
        moInfo.contact = userMO;
        userMO.contactInfo = moInfo;

where createContactInfoManagedObject returns an object of type ContactInfo. I'm getting following exception on the line

        moInfo.contact = userMO;


Unacceptable type of value for to-one relationship: property = "contact"; desired type = Contact; given type = NSManagedObject; value = <NSManagedObject: 0x3b2850> (entity: User; id: 0x3d4fa0 <x-coredata://4889CBE0-094B-49DB-B525-C87F7CD1AA68/User/p1> ; data: {
    contacts =     (
     开发者_开发知识库   "0x3d4fa0 <x-coredata://4889CBE0-094B-49DB-B525-C87F7CD1AA68/User/p1>"
    );
    user = "0x3d4fa0 <x-coredata://4889CBE0-094B-49DB-B525-C87F7CD1AA68/User/p1>";
    contactInfo = "0x3ebdc0 <x-coredata:///VCard/t128311BC-4B82-45CF-B87C-9AD38CBC89163>";
}).

My question is what's wrong here? I think something 's wrong with inheritance when I try to assign User entity to a contact relationship. Please advise! Thank you

Where is your userMO object coming from?

The error message suggests it is an instance of NSManagedObject, but it is expecting an instance of Contact.

try to cast the object:

 ContactInfo *moInfo =(ContactInfo*) [self createContactInfoManagedObject];