Hello everybody,

this is my first message in this group and that is why I shortly want
to introduce myself. My name is Tilo and I am working for an IT
Company in Rome, Italy. In this group I hope to gather some help for
my first steps using Firebird Databases in combination with the Java
Desktop Application Wizard of Netbeans 6.0. On the other side I hope
to be able to help other users when I have already made some
experiences that regard their problems.

The situation is the following: I tried to set up a small database
application using the wizard of Netbeans 6.0 and a Firebird database.
The use of the default entity manager toplink ended in the following
error, that I did send to Roman Rokytskyy. His answer, that brought me
to this group, you can also find attached:

*********************************************************

Hi,

> We are working with Netbeans IDE 6.0 and the wizard for java database
> desktop applications. The implementation of some of the tables of our
> database works without any problem. Some other tables cause a strange
> error, which we weren't able to resolve jet.
>
> The error refers to a problem with the tag @joincolumn:
>
> When the source entity *class* uses a composite primary key, a
> @JoinColumn must be specified *for* each join column using the
> @JoinColumns. Both the name and the referenceColumnName elements

must be

> specified in each such @JoinColumn.
>
> Could you be so kind to give me a hint how I can go on?

I suspect that you're using JPA, however I did not use that technology
so far - I'm using Hibernate. Please join the Firebird-Java group
(http://groups.yahoo.com/group/Firebird-Java) and ask the question there
- it is always better to use mailing lists or discussion groups.

Best regards,
Roman Rokytskyy

*********************************************************

First of all I want to thank Roman Rokytskyy. I already red his name
several times in the messages of this group, so I think that he is
quite active here.

After having red his mail I tried to change the used entity manager to
the mentioned Hibernate. When I change the settings in the
persistence.xml file of the created project, I receive an error that I
didn't see before:

*********************************************************

The following providers:
oracle.toplink.essentials.PersistenceProvider
oracle.toplink.essentials.ejb.cmp3.EntityManagerFactoryProvider
Returned null to createEntityManagerFactory.

*********************************************************

The errors obviously still refer to toplink entity managers.

For now I think that the informations are sufficient. Maybe anyone has
already an idea what is going wrong. If there are any informations
missing, please let me know!

Thank you very much for the efforts in forward.

Tilo