The property 'Id' is part of the object's key information and cannot be modified

Question

i\'m using Entity Framework 4.0 and having a silly problem that i can\'t figure out.

I have two tables:

1. Contact: Id (primary key), Value, ContactTypeId

Answer 1

There are two types of associations. Independant association where the related key would only surface as navigation property. Second one is foreign key association where the related key can be changed using foreign key and navigation property. So you can do the following.

//option 1 generic option

var contacttype = new ContactType{Id = 3};
db.ContactTypes.Attach(contacttype);
customer.ContactType = contacttype;

option 2 foreign key option

contact.ContactTypeId = 3;

//generic option works with foreign key and independent association

contact.ContactReference.EntityKey = new EntityKey("container.contactset","contacttypeid",3);