sql2000触发器没有效率

CREATE TRIGGER tr_mys_yz_update ON dbo.mys_yz 

FOR  UPDATE 

AS



if ( update( sfbz) )

begin



  --更新手术的收费标志

  Update a set sfbz = '1'  

  from ss_sqd a inner join inserted b on a.djh = b.sqdbh and b.sqdfl = 'ss' 

      inner join deleted  c on b.yzh = c.yzh and b.yzxh = c.yzxh and isnull( b.sfbz,'0' ) = '0' and isnull(c.sfbz,'0' ) = '1'



  --更新检验的收费标志

  Update a set sfbz = '1'  

  from jy_jyd  a inner join inserted b on a.jydh = b.sqdbh and b.sqdfl = 'jy' 

      inner join deleted  c on b.yzh = c.yzh and b.yzxh = c.yzxh and isnull( b.sfbz,'0' ) = '0' and isnull(c.sfbz,'0' ) = '1'

   

--更新检查的收费标志

Update a set sfbz = '1'  

  from jc_jcd  a inner join inserted b on a.djh = b.sqdbh and b.sqdfl = 'jc' 

      inner join deleted  c on b.yzh = c.yzh and b.yzxh = c.yzxh and isnull( b.sfbz,'0' ) = '0' and isnull(c.sfbz,'0' ) = '1'

 

end

以上的触发器，语法没有错误，但是update mys_yz.sfbz update后，触发器没有作用。。。。请高手门帮忙看看把。。。。谢谢