sql 求助

[wranglergu]

select 1 as a,case 2 when 2 then 3 else 4 end as b,1*b as c

我想在字段c上用前面处理好的b字段，怎么使用呢。百度上实在不知道该怎么描述。所以....

[wranglergu]

可能没什么好办法了吧。

[SqlServer2008]

select a,1*b as c from
(
select 1 as a,case 2 when 2 then 3 else 4 end as b from tab
) t

[dawugui]

[Quote=引用楼主 wranglergu 的回复:]
SQL code
select 1 as a,case 2 when 2 then 3 else 4 end as b,1*b as c


我想在字段c上用前面处理好的b字段，怎么使用呢。百度上实在不知道该怎么描述。所以....
[/Quote]

select 1 as a,case 2 when 2 then 3 else 4 end as b,
(case 2 when 2 then 3 else 4 end )*b as c

[dawugui]

或者用子查询:
select t.* , b * 1 as c from
(...) t

[wranglergu]

我的意思是，因为b字段处理的太麻烦，所以，想在c中直接使用处理之后的b就不用

select 1 as a,case 2 when 2 then 3 else 4 end as b,1*(case 2 when 2 then 3 else 4 end) as c

[super007007007]

;with temp as(select 1 as a,case 2 when 2 then 3 else 4 end  as b)
select temp.*,temp.b * 1 as c from temp