Question

I’m using Ef 4 code first and have a parent table with a child

When I update the parent, I notice that the child is not updated, rather new entries are created (old ones are not deleted).

My update method looks like so:

IEFRepository<Parent> repo = new EFRepository<Parent>( context );
var parent = repo.GetSingle(m => m.parentId.Equals(updatedParent.parentId));

parent.Child = updatedParent.Child;  //this is creating a new record in the db, not overwriting the existing

repo.Update(parent);

If I break out the child properties in the update method like below it solves the duplicate entry problem, but creates other issues elsewhere (primarily with validating null entries).

parent.Child.property = updatedParent.Child.property;

I also tried creating an UpdateChild(), and calling that from UpdateParent(), but got essentially the same result as breaking out the individual child properties

Is there a proper way to control this behavior and force EF to overwrite the child entity instead of creating a new one?

Answer 1

Have a list of childs in a context and remove old child from your context when you don’t need it anymore.