Google App Engine - DELETE JPQL Query and Cascading

问题

I noticed that the children of PersistentUser are not deleted when using the JPQL query below. However, the children are deleted if I perform an entityManager.remove(object). Is this expected? Why doesn't the JPQL query below also perform a cascaded delete?

@OneToMany(mappedBy = "persistentUser", cascade = CascadeType.ALL)
private Collection<PersistentLogin> persistentLogins;

...

@Override
@Transactional
public final void removeUserTokens(final String username) {
    final Query query = entityManager.createQuery(
        "DELETE FROM PersistentUser p WHERE username = :username");
    query.setParameter("username", username);
    query.executeUpdate();
}

回答1:

This is expected, the JPQL delete operation does not cascade. From the JPA 1.0 specification:

4.10 Bulk Update and Delete Operations

(...)

A delete operation only applies to entities of the specified class and its subclasses. It does not cascade to related entities.

来源：https://stackoverflow.com/questions/2995693/google-app-engine-delete-jpql-query-and-cascading