Entity Framework: Setting a Foreign Key Property

Question

We have a table that looks roughly like this:

CREATE TABLE Lockers 
{
  UserID int NOT NULL PRIMARY KEY (foreign key),
  LockerStyleID int (foreign key),
  NameplateID int (foreign key)
}

All of the keys relate to other tables, but because of the way the application is distributed, it's easier for us to pass along IDs as parameters. So we'd like to do this:

Locker l = new Locker { 
  UserID = userID, 
  LockerStyleID = lockerStyleID, 
  NameplateID = nameplateID 
};
entities.AddLocker(l);

We could do it in LINQ-to-SQL, but not EF?

Answer 1

This missing feature seems to annoy a lot of people.

• Good news: MS will address the issue with .NET 4.0.
• Bad news: for now, or if you're stuck on 3.5 you have to do a little bit of work, but it IS possible.

You have to do it like this:

Locker locker = new Locker();
locker.UserReference.EntityKey = new System.Data.EntityKey("entities.User", "ID", userID);
locker.LockerStyleReference.EntityKey = new EntityKey("entities.LockerStyle", "ID", lockerStyleID);
locker.NameplateReference.EntityKey = new EntityKey("entities.Nameplate", "ID", nameplateID);
entities.AddLocker(locker);
entities.SaveChanges();