Entity Framework: Updating a field to a null value?

I'm using stubs to update my entities and when the updated entity consists of columns that have values changed from non-nulls to nulls, the nulls are not persisted to the database i.e. the record continues to hold the previous non-null values.

What am 开发者_开发知识库I doing wrong?

public void UpdateEntity(Entity e)
        {
            _context.Works.Attach(new Entity{ Id = e.Id });
            _context.ApplyCurrentValues("Entities", e);
            _context.SaveChanges();
        }

---

The problem is that you need to assign null to these properties after you Attach(), not before. Perhaps ApplyCurrentValues() only copies non-already-identical properties? (I've never tested, but it would be reasonable if it did.)

---

Try to avoid loading entities using Attach. If you just get entity from DB, you don't have to bother with settings flags on nulled items:

var stage = Db.Stages.First(s => s.ID == someId);
stage.Notation = vm.Notation; // can be also null
Db.SaveChanges();