插入多个继承的实体会产生-无法确定关系的主要终点

Question

I'm using EF5 and I'm having an issue where I can add 1 instance of an inherited entity and save it successfully, but if I add two or more instances of the type, I run into the issue below.

These entities are inherited types from a base type. FkEssayItemContent is the FK relationship that ties my type, EssayItem , to it's base, Content .

Unable to determine the principal end of the 
'TDSModel.FkEssayItemContent' relationship. 
Multiple added entities may have the same primary key.

What am I missing here, such that one entity would insert fine, but two of them inserted at once would cause this problem when using inheritance?

Thanks!

Answer 1

I ended up answering this myself. It turns out that in addition to an inheritance relationship, the model had an association between EssayItem and `Content'. Removing that association and maintaining the inheritance fixed the issue.