Hibernate遇到的问题

设计Student、Teacher表 多端Student有外键关联Teacher

在做级联删除测试的时候出现一个很想不明白的问题：

Session session1 = sf.openSession();

Transaction tran = session1.beginTransaction();

Teacher t = new Teacher();
t.setTid("4028803538c72b670138c72b68a30001");

session1.delete(t);

tran.commit();

session1.flush();

session1.close();

}

结果只是把Teacher这条记录删掉了，在student表里的TID外键字段值删掉，并没有想象中删掉Student的关联记录

Session session1 = sf.openSession();

Transaction tran = session1.beginTransaction();

Teacher t=(Teacher)session1.get(Teacher.class, "4028803538c72b670138c72b68a30001");

session1.delete(t);

tran.commit();

session1.flush();

session1.close();

}

改成这种方式就OK......