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JPA/Hibernate: on delete set null

Yes @PreRemove() is a good way to go. But you need to have the bidirectional association on the inverse side, meaning Employee should have a @OneToMany with Employee (employees under supervision). And then add this method in Employee:

private void removeAssociationsWithChilds() {
   for (Employee e : employees) {

But, if you don't want to keep track on the inverse side, meaning if you don't want to have a list of employees under supervision by the boss using @OneToMany, then you will have to do it manually via HQL just before deletion, such as update Employee e set e.boss = null where e.boss = ?, and then delete the boss.

Categories : SQL

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