Problem Joining 3 Tables

[mwilmes]

Hi,

I have two Entities A and B each with a simple primary key idA and idB. I join them using a third table AB that has a composite primary key using an embedded primary key class ABPk. So far it works fine.

Now I got another table C with a simple primary key idC involved that has to be joined with AB using another table ABC. So this last table has a composite primary key ABCpk that consists of the parts idC and ABPk which itself consists of idA and idB.

All composite primary keys use the @Embeddable Annotation and are imbedded using @EmbeddedId similar to what is recommended in https://www.jboss.org/community/wiki/EJB3relationships

My problem is that on ABC I can't activate the @ManyToOne Annotation that references AB. On deployment this gives me a NullPointerException.

I am using JBoss 4.2.3.GA with Sun Java 1.6.0.16.

Thanks
Martin

[wolfgangknauf]

Hi Martin,

could you post the relevant snippets of your deployment and also the exception + stacktrace?
I never tried it with such a nested relationship, so unfortunately I cannot provide you with a quick solution.

What are your "FetchType" declarations? Probably all LAZY and no EAGER?

You might find more help is you ask this question in the hibernate forums at https://forum.hibernate.org/index.php . If you find help there, you might update the Wiki article to point at this problem.

Best regards

Wolfgang

[mwilmes]

Hi Wolfgang,

thanks for your answer. I will do as you recommend but that will take some time since I am very busy currently.

Best regards
Martin