title: remove related @OneToOne automatically in JPA
body: <p>I'm using the following in JPA:</p>
  
  <pre><code>@Entity
  class ParentClass {
    @Id
    @GeneratedValue
    private long id;
    ...
    @OneToOne(cascade = { cascade = { CascadeType.ALL }, 
                          mappedBy = "parentClass")
    ChildClass child;
    ..
  }
  
  @Entity
  class ChildClass {
  
    @OneToOne
    ParentClass parentClass;
  
  }
  </code></pre>
  
  <p>If I do a Query like createQuery("DELETE FROM ParentClass pc"), my child Class is not deleted automatically.</p>
  
  <p>Can this be done with JPA-2.0? (I does work with @OneToMany relationships).</p>