sq如何实现多字段分组

[tomzjt123]

比如我有以下分组
a b
1 2
2 3
4 5


我想把a b 两组内容不重复的列出来

得到 1 2 3 4 5

应该怎么写sql语句?

[中国风]

declare @s nvarchar(4000)
set @s=''
select @s=@s+' '+a
from (select a from t
union 
select b from t
)t
order by a

print ltrim(@s)

[中国风]

use Tempdb
go
SET NOCOUNT ON;
--> --> 
 
if not object_id(N'Tempdb..#T') is null
	drop table #T
Go
Create table #T([a] int,[b] int)
Insert #T
select 1,2 union all
select 2,3 union all
select 4,5
Go

declare @s nvarchar(4000)
set @s=''
select @s=@s+' '+RTRIM(a)
from (select a from #T
union 
select b from #T
)t
order by a

print ltrim(@s)
/**/
1 2 3 4 5
*/

Select ' '+lTRIM(a) 
FROM 
(SELECT a from #T
UNION 
Select b from #T)t FOR XML PATH('')
/*
 1 2 3 4 5
*/

[--小F--]

;with f as
(
select a from t
union 
select b from t
)

declare @s varchar(1000)
select @s=isnull(@s+' ' , '')+a from f

select @s

[geniuswjt]

select a from tb
union
select b from tb

[Quote=引用楼主 tomzjt123 的回复:]
比如我有以下分组
a b
1 2
2 3
4 5


我想把a b 两组内容不重复的列出来

得到 1 2 3 4 5

应该怎么写sql语句?
[/Quote]

[geniuswjt]

哦，再行转列下[Quote=引用 4 楼 geniuswjt 的回复:]

SQL code

select a from tb
union
select b from tb

引用楼主 tomzjt123 的回复:
比如我有以下分组
a b
1 2
2 3
4 5


我想把a b 两组内容不重复的列出来

得到 1 2 3 4 5

应该怎么写sql语句?
[/Quote]

[q465897859]

Create table #T([a] int,[b] int)
Insert #T
select 1,2 union all
select 2,3 union all
select 4,5
Go
select  name=stuff((select distinct ' '+ltrim(a) from  (select a from #t 
union all
select B from #T)a for xml path('')),1,1,'')