sql 语句中 group by 子句的问题，高手来看

[symbol_bc]

比如我有这样的查询， select col1,col2,col3 from table group by col1,col2,col3 这样没问题，
但是我有这样的查询 select col1, (select ... ...) as col2, (select .. ... )as col3 group by col1,col2,col3

用别名分组不行，就说别名不可识别 ，求救

[hello_syt]

先顶着！

[grearo]

select col1,col2,col3 from (select col1, (select ... ...) as col2, (select .. ... )as col3)  group by col1,col2,col3 

[love_cloud]

[Quote=引用 2 楼 grearo 的回复:]
SQL codeselect col1,col2,col3from (select col1, (select ... ...)as col2, (select .. ... )as col3)groupby col1,col2,col3
[/Quote]
正解

[阿非]

declare @t table(
name varchar(10)
)
insert into @t select '1'
insert into @t select '2'
insert into @t select '3'
insert into @t select '4'

select * from @t
select name from @t group by name
--错误的用别名分组 
--select name n from @t group by n
--使用别名分组
select *  from (select name n from @t) t group by n

[symbol_bc]

为什么第一种不行呢？查询的时候没问题啊

[Aderlee]

第二种的col2,col3是你自己命名的，不属于table，所以无法识别。

[王者coco]

学习了