Question

I use JPA with Hibernate.

I have a User class and a Flag class :

class User
{
    // ...
}

class Flag
{
    @OneToOne(optional=false)
    private User user;

}

I dont want/need a reference to the Flag object in the User class (and that’s the main point). But when I delete a User, I’d like the associated Flag (if there’s one) to be deleted too, without any foreign key constraint fails exception!

I know I could add a reference to the Flag inside the User, like :

class User
{
    @OneToOne(optional=true, cascade=CascadeType.ALL, mappedBy="user")
    @org.hibernate.annotations.Cascade(value=org.hibernate.annotations.CascadeType.DELETE_ORPHAN)
    private Flag flag;
}

And then the Flag object would be deleted when I delete the user.

But is it possible to cascade delete the Flag without having a reference to it in the User?

If not, what if the correct way to delete such an object?

Answer 1

You can’t cascade the delete automatically in this case, you’ll need to implement your own delete.

When you delete a user, first run a query like:

delete from Flag F where F.userId = :userId