Hi Ramu, which line causes the error? I assume it is "Project project = manager.merge(deleteProject);"? This one is problematic, because you first load the project, then get the BuyerRating and VendorRating collections, and after this delete the relationships by executing a delete query. This will keep the collections in memory in your loaded project, but they don't exist in the database. My suggestion is to change your code this way: -First delete BuyerRating and VendorRating -After this load the project by "Project deleteProject = manager.find(Project.class, projectId); " Currently, you do it the other way round. Hope this helps Wolfgang View the original post : http://www.jboss.org/index.html?module=bb&op=viewtopic&p=4209042#... Reply to the post : http://www.jboss.org/index.html?module=bb&op=posting&mode=reply&a...