Hi! According to the that comment below, it is not possible to work with relation sets, if the calling method ist executed with tx = null. The getIdList() requires a tx or else the setHandle is always null -> which means that JBOSS (4.0.2) does not allow something like person.getRelatives().iterator() if the tx is null. Can someone confirm this? public class RelationSet implements Set { | private JDBCCMRFieldBridge cmrField; | private EntityEnterpriseContext ctx; | private List[] setHandle; | private Class relatedLocalInterface; | | // | // Most of this class is a boring wrapper arround the id set. | // The only interesting hitch is the setHandle. This class doesn't | // have a direct referance to the related id set, it has a referance | // to a referance to the set. When the transaction is completed the | // CMR field sets my referance to the set to null, so that I know that | // this set is no longer valid. See the ejb spec for more info. | // | | public RelationSet( | JDBCCMRFieldBridge cmrField, | EntityEnterpriseContext ctx, | List[] setHandle) { | | this.cmrField = cmrField; | this.ctx = ctx; | this.setHandle = setHandle; | relatedLocalInterface = cmrField.getRelatedLocalInterface(); | } | | private List getIdList() { | if(setHandle[0] == null) { | throw new IllegalStateException("A CMR collection may only be used " + | "within the transction in which it was created"); | } | | Source: http://www.cenqua.com/clover/eg/jboss/report/org/jboss/ejb/plugins/cmp/jd... -- Alex View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3974508#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...