When I use WHERE, new problem happened: 20:19:38,796 ERROR [PARSER] Path expected for join! 20:19:38,796 ERROR [PARSER] Invalid path: 'd.centerName' 20:19:38,828 ERROR [PARSER] Invalid path: 'd.centerId' 20:19:38,828 ERROR [PARSER] right-hand operand of a binary operator was null 20:19:38,828 ERROR [[ZCZ0001Action]] Servlet.service() for servlet ZCZ0001Action threw exception javax.ejb.EJBTransactionRolledbackException: org.hibernate.hql.ast.QuerySyntaxException: Path expected for join! [ SELECT c.id ,c.centerId ,c.centerName ,c.centerFullName ,c.address1 ,c.address2 ,c.zipCode ,c.tel1 ,c.tel2 ,c.fax ,c.homepage ,c.parentCenterId ,c.remark ,d.centerName FROM com.zeng.db.M_Center c LEFT OUTER JOIN M_Center d WHERE c.parentCenterId = d.centerId ORDER BY c.levelDesc ] at org.jboss.ejb3.tx.Ejb3TxPolicy.handleInCallerTx(Ejb3TxPolicy.java:89) ... Please help me! View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=3984862#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...