Hey,
Do you recommend a book that covers JPA very well (not only the basic things)?
"Java Persistence with Hibernate" although is well detailed but it is so massive and some how can get you lost.
Thanks for help and time.
Clearly "Hibernate made easy" by Cameron McKenzie! Expensive but well worth it. If you need more advanced stuff like composite primary keys composed of other tables' primary keys there's probably no book out there telling you how to do it.
Another resource I've found that doesn't "babble" is