Removing child from collection using JPA

Question

I'm using JPA over Hibernate in my web-app. Here are two entities (only getters are shown):

class Child {   private Parent parent;    @ManyToOne(optional=false)   @JoinColumn(name="parent_id", referencedColumnName="parent_id", nullable=false, updatable=false)   public Parent getParent() {     return parent;   } }  class Parent {   private Collection<Child> children;    @OneToMany(fetch=FetchType.EAGER, mappedBy="parent", cascade={CascadeType.ALL})   public Collection<Child> getChildren() {     return children;   } } 

As you see Parent and Child relate as "one-to-many".

Now I need to load a Parent instance, remove some or all children and save the changes. Below is code which does not work for me:

Parent p = entityManager.find(Parent.class, 12345L); // load entity p.getChildren().clear(); // remove all children entityManager.merge(p); // try to save 

Child entities are not remove in the example above. Now I have to manually call entityManager.remove() for each child.

Is there any easier way to manage child collection?

Please notice that I don't want to use Hibernate-specific functionality, only pure JPA.

Answer 1

For JPA 2.0 you can set orphanRemoval=true of the @OneToMany

For JPA 1.0, you should use hibernate-specific annotations. That is the @Cascade annotation (instead of the cascade attribute), with a value of

@Cascade({CascadeType.ALL, CascadeType.DELETE_ORPHAN}) 

Hibernate 3.5+ implement JPA 2.0