bidirectional one-to-many

sdroovan · **Posted:** Sat Apr 08, 2006 11:57 am

I'm unable to set up a bidirectional one-to-many relationship.

Code:

public class Person() {

...

   @OneToMany(mappedBy="person")
   public Set<Invoice> getInvoices() {
      return invoices;
   }
}

Code:

public class Invoice() {

...

        @ManyToOne
        @JoinColumn(name="fk") 
   public Person getPerson() {
      return person;
   }
}

I use this method to save the person object. (eg: saveOrUpdate(new Person(...));

Code:

   protected void saveOrUpdate(Object obj) {
      try {
         startOperation();
         session.saveOrUpdate(obj);
         tx.commit();
      } catch (HibernateException e) {
         HibernateFactory.rollback(tx);   
         handleException(e);
      } finally {
         HibernateFactory.close(session);
      }
   }

I tried many variants on this, but I always get a unidirectional relationship instead of a bidirectional relationship.

Here are some examples of variants I tried, but without result.

Code:

@ManyToOne(cascade=CascadeType.PERSIST)
@JoinColumn(name="fk", insertable=false, updatable=false)

...

@OneToMany (targetEntity=Invoice.class, mappedBy="invoice", cascade=CascadeType.ALL)

...

Why can I never get a bidirectional relationship???

bigm25 · **Joined:** Tue Mar 28, 2006 4:03 pm **Posts:** 11

I don't understand your question.
What exactly makes you believe that you

Quote:

get a unidirectional relationship instead of a bidirectional relationship

?

sdroovan · **Posted:** Sun Apr 09, 2006 4:23 am

First of all, thanks for your reply...

Simply because one time, I have an entry in the person-invoice table but no entry in the column fk of the invoice table. And the other time I get the opposite.

Also when I retrieve an object back from the database (an invoice or a person object), one time I can do invoice.getPerson() but not person.getInvoices(), and the other time I can do person.getInvoices() but not invoice.getPerson().
(with 'I can do' I mean that I can get the right object back out of the database, the other times I get nothing (null))

emmanuel · **Posted:** Sun Apr 16, 2006 1:13 pm

you need to check in the documentation what mappedBy (or inverse) means