JPA 2: multiple column usage in foreign keys

Question

I am using Hibernate as persistence provider and modelling my entities with JPA 2.

Now a question came up and i hope you can help me.

In my application you can

Answer 1

Are you sure you can't use insertable = false, updateable = false for these @JoinColumns?

As far as I understand, you can initialize gameid once by setting game property, and after that you don't need to change it since Tiles and Groups belong to the same Game.