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

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

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探讨

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....


------解决方案--------------------
SQL code

;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