Reference and EntityKey

When add an entity to your objectContext, if the entity reference an other existing entity, but that entity is not in memory, you need to create a EntityKey like the following.

var address = new Address(); address.City = "SomeCity"; address.AddressType = "Home"; address.ModifiedDate = DateTime.Now; address.ContactReference.EntityKey = new EntityKey("PEF.Contacts", "ContactID", 709); context.AddToAddresses(address); context.SaveChanges();