"mnrz" wrote : | 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 I probably am not understanding the requirements of your application correctly. Can't you calculate the ID from the formula using your algorithm, before calling the persist method on entity manager? What i am trying to understand is why does the ID calculation or setting any other field be part of the callback method. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4147855#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...