"waynebaylor" wrote : You have a not-null constraint on the status_ field, so i would check to see why the object you're merging has status_=null. Yes, exactly. The point is that the object I'm sending to the struts form doesn't have all the fields for update - I mean the object is there, complete, but the struts form doesn't display all the fields. I think, somehow, struts must be setting the fields not "visible for update" to null and thats why.. I've found a workaround, which is placing the fields on the JSP page as hidden fields and that works perfect But by doing that, everytime a new field comes in, I need to update the page - which is not a big deal but, from my point of view, the system should handle it. Regards, Tarcio View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4046363#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...