Description gabriele 2020-03-08 16:40:18 EDT

Created attachment 282044 [details]
Junit Test

I have to increase the version of the Parent entity when updating/removing a child Entity
I have two entities: Parent and Child 
The Child entity contains the reference to the Parent entity.

public class Parent {
@Id
private String id;
@OneToMany(cascade = { CascadeType.ALL }, mappedBy = "parent")
private Set<Child> children;
....
}

public class Child {
@Id
private String id;
@ManyToOne(cascade = { CascadeType.ALL })
@JoinColumns({ @JoinColumn(name = "parent_fk", referencedColumnName = "id") })
private Parent parent;
}

I remove all the children of a given parent and then force the update version of the parent entity.
This does not work if, before doing the look, an flush is performed.

Example:
        flush = true
        em.getTransaction().begin();
        Parent p = em.find(Parent.class, PARENT_ID);
        Set<Child> children = p.getChildren();
        assertEquals(3, children.size());
        Child c = em.find(Child.class, "child1");
        children.remove(c);
        if (flush) {
            em.flush();
        }
        p = em.merge(p);
        em.lock(p, LockModeType.OPTIMISTIC_FORCE_INCREMENT);
        em.getTransaction().commit();
        p = em.find(Parent.class, PARENT_ID);
        assertEquals(2, children.size());
        assertEquals(2, p.getUpdateVersion());