合并分拆表_整理贴1

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2008-06-12 10:33:01

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--合并分拆表

/******************************************************************************************************************************************************

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)

*/





拆分表:



--> --> (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(5))

Insert Tab

select 1,N'a,b,c' union all

select 2,N'd,e' union all

select 3,N'f'

Go



SQL2000用辅助表:

if object_id('Tempdb..#Num') is not null

	drop table #Num

go

select top 100 ID=Identity(int,1,1) into #Num from syscolumns a,syscolumns b

Select 

	a.Col1,COl2=substring(a.Col2,b.ID,charindex(',',a.Col2+',',b.ID)-b.ID) 

from 

	Tab a,#Num b

where

	charindex(',',','+a.Col2,b.ID)=b.ID --也可用 substring(','+a.COl2,b.ID,1)=','





SQL2005用Xml:



select 

	a.COl1,b.Col2

from 

	(select Col1,COl2=convert(xml,'<root><v>'+replace(COl2,',','</v><v>')+'</v></root>') from Tab)a

outer apply

	(select Col2=C.v.value('.','nvarchar(100)') from a.COl2.nodes('/root/v')C(v))b









SQL05用CTE:



;with roy as 

(select Col1,COl2=cast(left(Col2,charindex(',',Col2+',')-1) as nvarchar(100)),Split=cast(stuff(COl2+',',1,charindex(',',Col2+','),'') as nvarchar(100)) from Tab

union all

select Col1,COl2=cast(left(Split,charindex(',',Split)-1) as nvarchar(100)),Split= cast(stuff(Split,1,charindex(',',Split),'') as nvarchar(100)) from Roy where split>''

)

select COl1,COl2 from roy order by COl1 option (MAXRECURSION 0)



生成结果:

/*

Col1        COl2

----------- -----

1           a

1           b

1           c

2           d

2           e

3           f

*/