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----乌龟代码---
合并列值
--*******************************************************************************************
表结构,数据如下:
id value
----- ------
1 aa
1 bb
2 aaa
2 bbb
2 ccc
需要得到结果:
id values
------ -----------
1 aa,bb
2 aaa,bbb,ccc
即:group by id, 求 value 的和(字符串相加)
1. 旧的解决方法(在sql server 2000中只能用函数解决。)
--=============================================================================
create table tb(id int, value varchar(10))
insert into tb values(1, 'aa')
insert into tb values(1, 'bb')
insert into tb values(2, 'aaa')
insert into tb values(2, 'bbb')
insert into tb values(2, 'ccc')
go
--1. 创建处理函数
CREATE FUNCTION dbo.f_strUnite(@id int)
RETURNS varchar(8000)
AS
BEGIN
DECLARE @str varchar(8000)
SET @str = ''
SELECT @str = @str + ',' + value FROM tb WHERE id=@id
RETURN STUFF(@str, 1, 1, '')
END
GO
-- 调用函数
SELECt id, value = dbo.f_strUnite(id) FROM tb GROUP BY id
drop table tb
drop function dbo.f_strUnite
go
/*
id value
----------- -----------
1 aa,bb
2 aaa,bbb,ccc
(所影响的行数为 2 行)
*/
--===================================================================================
2. 新的解决方法(在sql server 2005中用OUTER APPLY等解决。)
create table tb(id int, value varchar(10))
insert into tb values(1, 'aa')
insert into tb values(1, 'bb')
insert into tb values(2, 'aaa')
insert into tb values(2, 'bbb')
insert into tb values(2, 'ccc')
go
-- 查询处理
SELECT * FROM(SELECT DISTINCT id FROM tb)A OUTER APPLY(
SELECT [values]= STUFF(REPLACE(REPLACE(
(
SELECT value FROM tb N
WHERE id = A.id
FOR XML AUTO
), ' <N value="', ','), '"/>', ''), 1, 1, '')
)N
drop table tb
/*
id values
----------- -----------
1 aa,bb
2 aaa,bbb,ccc
(2 行受影响)
*/
--SQL2005中的方法2
create table tb(id int, value varchar(10))
insert into tb values(1, 'aa')
insert into tb values(1, 'bb')
insert into tb values(2, 'aaa')
insert into tb values(2, 'bbb')
insert into tb values(2, 'ccc')
go
select id, [values]=stuff((select ','+[value] from tb t where id=tb.id for xml path('')), 1, 1, '')
from tb
group by id
/*
id values
----------- --------------------
1 aa,bb
2 aaa,bbb,ccc
(2 row(s) affected)
*/
drop table tb
http://dev.yesky.com/394/2429894.shtml
if object_id('tb') is not null drop table tb
create table tb(检验员 varchar(10), 打印日期 nvarchar(10), 漏检次数 int)
go
insert tb select '罗邦卫','2009-7-31',2
insert tb select '梅强','2009-7-31',2
insert tb select '周林江','2009-7-31',1
insert tb select '周强','2009-7-31',3
insert tb select '陈刚','2009-8-1',1
insert tb select '陈华林','2009-8-1',2
insert tb select '董加军','2009-8-1',1
insert tb select '罗邦卫','2009-8-1',2
insert tb select '方文祥','2009-8-1',2
insert tb select '周林江','2009-8-1',2
insert tb select '周强','2009-8-1',1
insert tb select '陈刚','2009-8-3',1
insert tb select '陈华林','2009-8-3', 1
insert tb select '陈杰','2009-8-3',3
insert tb select '李林峰','2009-8-3',1
go
declare @sql nvarchar(4000)
set @sql='select 检验员' --变量必须初始化赋值
select @sql=@sql+
N','+quotename(打印日期)+
N'=max(case 打印日期 when '+quotename(打印日期,N'''')+ --quotename(打印日期)=[打印日期],打印日期(打印日期,N'''')='2009-8-3'......
N' then 漏检次数 else 0 end)'
from tb group by 打印日期 --按日期分组
print @sql
exec(@sql+N' from tb group by 检验员')
go
检验员 2009-7-31 2009-8-1 2009-8-3
陈刚 0 1 1
陈华林 0 2 1
陈杰 0 0 3
董加军 0 1 0
方文祥 0 2 0
李林峰 0 0 1
罗邦卫 2 2 0
梅强 2 0 0
周林江 1 2 0
周强 3 1 0
动态SQL-------合并表-------
/******************************************************************************************************************************************************
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'
Go
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
go
Select distinct Col1,Col2=dbo.F_Str(Col1) from Tab
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>')
)b
SQL05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)
*/