Hibernate单向多对一和级联删除

Question

i am newbie in Hibernate and i need unidirectional many-to-one with on delete cascade.

Apparently the only option is, when the parent knows about its children. But what if I do it manually via SQL? Is this solution good?

alter table CHILDREN 
add constraint FK_i4jjy61om foreign key (PARENT)
references PARENT
on delete cascade;

Answer 1

You can use SQL ON DELETE CASCADE , but you have to be careful to evict all Child entities belonging to the Parent you are about to delete.

If you already loaded a Parent's Child, when you delete the Parent, the Child will be deleted from the database without Hibernate knowing about the entity state change .

To address this situation, it's better to evict all associated Child entities, to make sure you don't accidentally re-persist them through some other associations transitive persistence .