Multiplicity Constraint Violated. The Role Child_parent_target Of The Relationship Child_parent Has Multiplicity 1 Or 0..1

I did a lot of research but haven't found any answer that matches my problem. I even tried to use the The relationship could not be changed because one or more of the foreign-key p

Solution 1:

I was able to solve my problem using GraphDiff amazing library. It just does everything for us when talking about parent/child persisting.

Check it out at this post: GraphDiff - Allowing automated updates of a graph of detached entities