update left join 语句求解答

[chenstu]

UPDATE a
SET price=c.price
from (select a.oldcode from a WITH (nolock)
left join b with (nolock) on a.codeid=b.codeid
left join c with(nolock)
on a.stu=c.stu and c.id='value'
where b.pdid='00' and a.price is null))

请问我这样子更新是否是正确的呢？

[cxmcxm]

UPDATE       a   
SET       price=c.price 
from      a   WITH   (nolock)   
            left   join     b   with   (nolock)   on   a.codeid=b.codeid   
              left   join   c     with(nolock)   
                on   a.stu=c.stu   and   c.id= 'value ' 
where     b.pdid= '00 '   and   a.price   is   null

[中国风]

--改一下
set price=c.price 
from 
	a with(Nolock) 
left join
	b with(Nolock)  on a.codeid=b.codeid
left join 
	 c    with(nolock)  on   a.stu=c.stu   and   c.id= 'value ' 
where     b.pdid= '00 '   and   a.price   is   null

[中国风]

--不能把表（）起来,放在外连
update a
set price=c.price
from
a with(Nolock)
left join
b with(Nolock) on a.codeid=b.codeid
left join
c with(nolock) on a.stu=c.stu and c.id= 'value '
where b.pdid= '00 ' and a.price is null

[hzl620]

FROM中间我没有看懂，其它要是后面））是笔误，那其它都是对的

[chenstu]

谢谢各位的答案