Question

First CascadeType.Remove is not an option because the client side database may not support cascade operation.

I guess OrphanRemoval = true only handle @OneToXXX relationships.

How about many-to-one relationships?

For example a many-to-one mapping like this:

public class Order{
    ....
    @ManyToOne
    private Customer customer;
    .....
}

In Customer entity there is no mapping to Order which make the relationship become one-direction.

Then how can we remove all orders from a customer before removing that customer? Is there a simple automatic way to handle that or we have to implement the code explicitly via service layer and call something like findOrdersByCustomer(long customer_id) then remove them?

Thanks in advance.

Answer 1

Yes, you’ll need to find all the orders and remove them. Or you can also execute a JPQL query deleting everything:

delete from Order o where o.customer = :customer

Note that your note about CascadeType.REMOVE is wrong: it’s JPA that executes the cascade, and not the database. It’s thus supported whatever the database is.