Question

I created a Role entity, I would like to do CRUD operations on it. Everything works well, except the “D” (delete) operation.

I use something similar to this ObjectDB example code.

As stated in the WebPage quoted above,

An IllegalArgumentException is thrown
by remove if the argument is not a an
instance of an entity class or if it
is a detached entity.

How should I do that? What did I do wrong?

My Role entity is related to a User entity (a role can “have” several users, a user only one role). However, the Role instance I want to remove is by no means linked to any active user instances.

Answer 1

Thank you for your answer, but it did not help me much. Though I do think it was related to JTA.
I found out a solution however, so I ‘d like to share it here :

Instead of :

public void removeRole(Role aRole) {
    entityManager.remove(aRole);    
} 

All I had to do was :

public void removeRole(Role aRole) {
entityManager.remove(entityManager.merge(aRole));   
}

And that does the trick. Go figure.