So what's the gist of this? The UI I have in mind (or more precisely that is required by our client) simply cannot be implemented with all this sophisticated infrastructure (JPA, JSF, Seam) ? SelectMany... can't be used based on a OneToMany association? When I debug I find that when JSF/Seam calls setEmployees(employees) then each employee's department field is not updated. When I do that manually with some ugly code (updating both removed and added employees) my example works fine. Sigh - so I guess that's my only choice. View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4070580#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...