hibernate的三表查询

public class Cardgraderule implements java.io.Serializable {

    private Cardgrade cardgrade;
        ......
}


public class Cardgrade implements java.io.Serializable {

    private Acardtype cardtype;
        ......

public class BaseDAOHibernate extends HibernateDaoSupport{

    public List findAllByCriteria(final DetachedCriteria detachedCriteria)  throws DataAccessException  {
                return (List)getHibernateTemplate().execute(new HibernateCallback() { 

                    public Object doInHibernate(Session session)  throws HibernateException  {
                        Criteria criteria = detachedCriteria.getExecutableCriteria(session);
                        return criteria.list();
                    }
                }
        , true);
     }
}  

     DetachedCriteria cardy2 = DetachedCriteria.forClass(Cardgraderule.class, "cardgraderule");
     cardy2.createAlias("cardgrade","g")       
     　　　 .add(Restrictions.eq("g.cardtype.agentid", agenttbl.getAgentid()));
     List list = commonDao.findAllByCriteria(cardy2);

public class BaseDAOHibernate extends HibernateDaoSupport{
     
     public List find(String query)  throws DataAccessException {
       
         return getHibernateTemplate().find(query);
    }
}    

 String hql = "select distinct c from Cardgraderule c left join fetch c.cardgrade  g  left join fetch g.cardtype";
 List find = commonDao.find(hql);