JPA tips 2

A previous post about this topic: http://hilaltarakci.blogspot.com/2011/03/jpa-tips.html

Actually, long version of this post includes notes taken while i was reading Chapter 9- Working with Objects of book Java Persistence with Hibernate (http://www.manning.com/bauer2/). However, i could not post it because of the copyright rules..

 But at least, i can recommend to buy the book and read the whole chapter..