如何对ManyToOne关系强制执行孤儿删除。

@ManyToOne(fetch = LAZY)
@JoinColumn(name = COL_GROUP_ID, nullable = false, insertable = false, updatable = false, referencedColumnName = COL_ID)
@OnDelete(action = CASCADE)
@Cascade(value = DELETE_ORPHAN)
private Group group;