"jaikiran" wrote : | You should be setting the id before calling persist. Why are you trying to do that in a callback method? | thanks for your reply, the thing is that I want to calculate the ID from a formula in which I use an algorithm. however, if I set any field other than ID it won't work as well View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4147762#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...