Experience Summary 16--EF local data update

EF provides the function of updating some data of an object while retaining other data.

1. Re-instance an object and give the ID and fields to be modified. Note: The entity here cannot be queried from the database, but can only be a new instance.

Order order = new Order () {ID = id };
Order. Name = "test222 ";

2. Contains the object. The update policy is "Unchanged" and the fields to be updated are set.

DbEntityEntry <Order> entry = db. Entry <Order> (order );
Entry. State = EntityState. Unchanged;
Entry. Property (o => o. Name). IsModified = true;

3. Submit updates.
Db. SaveChanges ();