需要插入时如何在L2E或EF中使用外键？

Question

I know during the retrieve, I can use Include() to load related Entities ( how to use Foreign key in L2E or EF? ). but when I want to save or insert data, how to handle those reference Entities?

Answer 1

You need to hang the object within its graph, and call save changes. ObjectContext takes care of the rest.

Customer customer = myObjectContext.Single(c => c.Name == "Bob");

//new up an Order instance that has never been in the database.
Order order = GetOrderForCar();

//Add order to the Orders ObjectSet of a Customer
// This connects order to our ObjectContext.
customer.Orders.Add(order);

myObjectContext.SaveChanges();