{"id":2}

<dataset>
<CATEGORY CATEGORY_ID="1"
<CATEGORY CATEGORY_ID="2"
CATEGORY_PARENT_ID="1"/>
</dataset>

<dataset>
<CATEGORY CATEGORY_ID="1"/>
<CATEGORY CATEGORY_ID="2"/>
</dataset>   

@OneToOne( cascade = {CascadeType.ALL})
@JoinColumn(name = "CATEGORY_PARENT_ID")
@NotFound(action = NotFoundAction.IGNORE)
private Category parent;
@OneToMany( orphanRemoval = true, mappedBy = "parent", cascade = {CascadeType.ALL})
@NotFound(action = NotFoundAction.IGNORE)
private List<Category> children;
//...
getHibernateTemplate().merge(entity);