String hql ="from TbUser u ,TbLetter  l where  u.userId = l.tbUserByFkFromId.userId and l.toIsDelete=1 and  l.tbUserByFkToId.userId="+tbUser.userId+"order by l.letterIsRead desc , l.letterTime  desc"; 
  //查询 
  List result = userDao.query(pageNo, pageSize, hql.toString()); 
  //执行更新操作：把所有未读的letter更新为已经读 
  if(null != result && 0 != result.size()) 
  { 
  hql =new StringBuffer(" update tb_letter  set letter_is_read= 1 where letter_is_read=0 and fk_to_id =") ; 
hql.append(tbUser.getUserId()); 
userDao.excuteSql(hql.toString()); 
} 
    return  result ;