"Wolfgang Knauf" wrote : Hi, | | I think that the "name" attribute of the "@JoinColumn" denotes the column name in your "User" table. The "referencedColumn" should be the name of the primary key column in your child table. | Ok, I understand better. I found my id and columns back ... With this form, the sql generates a constraint with a random name for the foreign key. On the trace of jboss, I see something like : | alter table .Car add index FK107B4B78C84CE (USER_ID), add constraint FK107B4B78C84CE foreign key (USER_ID) references .User (id) | Is there a way of naming the foreign key : USER_CAR_FK instead of FK107B4B78C84CE ? Since the design was done in the database and not in the EJB annotation. Is it possible to have a strict mapping between a sql schema and a EJB annotation ? anonymous wrote : | But normally the @OneToOne annotation should work without any @JoinColumn annotations. The server will choose defaults for the column names. So, start with the easiest solution and remove the @JoinColumn annotation ;-). | | Hope this helps | | Wolfgang This helps a lot ;))) I'll follow your suggestion for small apps, but for big apps, I have to replicate the database schema, thus I try that. View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4217929#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...