I think I misunderstood the meaning of cascading in the context of a @ManyToOne
relationship.
The case:
public class User {
@OneToMany(fetch = FetchType.EAGER)
protected Set<Address> userAddresses;
}
public class Address {
@ManyToOne(fetch = FetchType.LAZY, cascade = CascadeType.ALL)
protected User addressOwner;
}
What is the meaning of the cascade = CascadeType.ALL
? For example, if I delete a certain address from the database, how does the fact that I added the cascade = CascadeType.ALL
affect my data (the User
, I guess)?
The meaning of CascadeType.ALL
is that the persistence will propagate (cascade) all EntityManager
operations (PERSIST, REMOVE, REFRESH, MERGE, DETACH
) to the relating entities.
It seems in your case to be a bad idea, as removing an Address
would lead to removing the related User
. As a user can have multiple addresses, the other addresses would become orphans. However the inverse case (annotating the User
) would make sense - if an address belongs to a single user only, it is safe to propagate the removal of all addresses belonging to a user if this user is deleted.
BTW: you may want to add a mappedBy="addressOwner"
attribute to your User
to signal to the persistence provider that the join column should be in the ADDRESS table.