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

For me the issue was caused by the lack of a Primary Key to my table, after setting a PK for the table the problem was gone

Answer 2

The entity that was created by the framework doesn't have a contact.ContactTypeId property. It automatically removed it and created the ContactType association inside the Contact entity.

The way to get it to work, as you suggested, is to create a ContactType object by querying the database and assigning it to contact.ContactType. For example:

Contact contact = dbContext.Contacts.Single(c => c.Id == 12345);
ContactType contactType = dbContext.ContactType.Single(c => c.Id == 3);
contact.ContactType = contactType;

Answer 3

In my case, I was creating an object declared and initialized together. I just initialized in the constructor or what you can initialize the object when required.