表结构
name style
a ww
a ee
b rr
c tt
c uu
查询出来是
name style
a ww/ee
b rr
c tt/uu
能不能group by 时用字符连接函数select出来,而不用cursor
name style
a ww
a ee
b rr
c tt
c uu
查询出来是
name style
a ww/ee
b rr
c tt/uu
能不能group by 时用字符连接函数select出来,而不用cursor
/********************************************************
合并分拆表数据整理人:中国风(Roy)日期:2008.06.06
*********************************************************/--> --> (Roy)生成測試數據
if not object_id('Tab') is null
drop table Tab
Go
Create table Tab([Col1] int,[Col2] nvarchar(1))
Insert Tab
select 1,N'a' union all
select 1,N'b' union all
select 1,N'c' union all
select 2,N'd' union all
select 2,N'e' union all
select 3,N'f'
Goselect * from Tab
--合并表:SQL2000用函数:go
if object_id('F_Str') is not null
drop function F_Str
go
create function F_Str(@Col1 int)
returns nvarchar(100)
as
begin
declare @S nvarchar(100)
select @S=isnull(@S+',','')+Col2 from Tab where Col1=@Col1
return @S
end
goSelect distinct Col1,Col2=dbo.F_Str(Col1) from Tab
go
/* STUFF学习SELECT STUFF('abcdef', 2, 3, 'ijklmn')
SELECT STUFF('abcdef', 2, 1, 'ijklmn')
SELECT STUFF('abcdef', 2, 0, 'ijklmn')
SELECT STUFF('abcdef', 1, 0, 'ijklmn')
GO*/
/***********************************
SQL2005用XML:
***********************************/
--方法1:select
a.Col1,Col2=stuff(b.Col2.value('/R[1]','nvarchar(max)'),1,1,'')
from
(select distinct COl1 from Tab) a
Cross apply
(select COl2=(select N','+Col2 from Tab where Col1=a.COl1 For XML PATH(''), ROOT('R'), TYPE))b方法2:select
a.Col1,COl2=replace(b.Col2.value('/Tab[1]','nvarchar(max)'),char(44)+char(32),char(44))
from
(select distinct COl1 from Tab) a
cross apply
(select Col2=(select COl2 from Tab where COl1=a.COl1 FOR XML AUTO, TYPE)
.query('<Tab>
{for $i in /Tab[position()<last()]/@COl2 return concat(string($i),",")}
{concat("",string(/Tab[last()]/@COl2))}
</Tab>')
)bSQL05用CTE:;with roy as(select Col1,Col2,row=row_number()over(partition by COl1 order by COl1) from Tab)
,Roy2 as
(select COl1,cast(COl2 as nvarchar(100))COl2,row from Roy where row=1
union all
select a.Col1,cast(b.COl2+','+a.COl2 as nvarchar(100)),a.row from Roy a join Roy2 b on a.COl1=b.COl1 and a.row=b.row+1)
select Col1,Col2 from Roy2 a where row=(select max(row) from roy where Col1=a.COl1) order by Col1 option (MAXRECURSION 0)
生成结果:
/*
Col1 COl2
----------- ------------
1 a,b,c
2 d,e
3 f(3 行受影响)
*/
RTRIM(MIN(style)) + CASE WHEN COUNT(*)>1 THEN '/' + RTRIM(MAX(style)) ELSE '' END AS style
FROM tb
GROUP BY name;
-- Author : liangCK 小梁 & angellan 兰儿
-- Comment: 小梁 爱 兰儿
-- Date : 2008-10-06 08:27:55
------------------------------------------------
--> 生成测试数据: @tb
DECLARE @tb TABLE (name VARCHAR(1),style VARCHAR(2))
INSERT INTO @tb
SELECT 'a','ww' UNION ALL
SELECT 'a','ee' UNION ALL
SELECT 'b','rr' UNION ALL
SELECT 'c','tt' UNION ALL
SELECT 'c','uu'--SQL查询如下:SELECT name,
RTRIM(MIN(style)) + CASE WHEN COUNT(*)>1 THEN '/' + RTRIM(MAX(style)) ELSE '' END AS style
FROM @tb
GROUP BY name;/*
name style
---- -----
a ee/ww
b rr
c tt/uu(3 行受影响)*/
insert into @tb select 'a','ww'
union all select 'a','ee'
union all select 'b','rr'
union all select 'c','tt'
union all select 'c','uu'
select name ,style= stuff((select '/'+style from @tb where a.name=name for xml path('')),1,1,'')
from @tb a group by name
name style
---------- ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
a ww/ee
b rr
c tt/uu(3 行受影响)