1.
List students = session.createQuery("select c.name, s.name from Student s inner join s.classes c").list();
            for (Iterator iter=students.iterator(); iter.hasNext();) {
                Object[] obj = (Object[])iter.next();
                System.out.println(obj[0] + "," + obj[1]);
            }

2.
//左连接
List students = session.createQuery("select c.name, s.name from Classes c left join c.students s").list();
            for (Iterator iter=students.iterator(); iter.hasNext();) {
                Object[] obj = (Object[])iter.next();
                System.out.println(obj[0] + "," + obj[1]);
            }