合并分拆表

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SQL code

--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 TabGoCreate table Tab([Col1] int,[Col2] nvarchar(1))Insert Tabselect 1,N'a' union allselect 1,N'b' union allselect 1,N'c' union allselect 2,N'd' union allselect 2,N'e' union allselect 3,N'f'Go合并表:SQL2000用函数:goif object_id('F_Str') is not null    drop function F_Strgocreate function F_Str(@Col1 int)returns nvarchar(100)asbegin    declare @S nvarchar(100)    select @S=isnull(@S+',','')+Col2 from Tab where Col1=@Col1    return @SendgoSelect distinct Col1,Col2=dbo.F_Str(Col1) from TabgoSQL2005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) aCross 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) across 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,c2           d,e3           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 TabGoCreate table Tab([Col1] int,[COl2] nvarchar(5))Insert Tabselect 1,N'a,b,c' union allselect 2,N'd,e' union allselect 3,N'f'GoSQL2000用辅助表:if object_id('Tempdb..#Num') is not null    drop table #Numgoselect top 100 ID=Identity(int,1,1) into #Num from syscolumns a,syscolumns bSelect     a.Col1,COl2=substring(a.Col2,b.ID,charindex(',',a.Col2+',',b.ID)-b.ID) from     Tab a,#Num bwhere    charindex(',',','+a.Col2,b.ID)=b.ID --也可用 substring(','+a.COl2,b.ID,1)=','SQL2005用Xml:select     a.COl1,b.Col2from     (select Col1,COl2=convert(xml,'<root><v>'+replace(COl2,',','</v><v>')+'</v></root>') from Tab)aouter apply    (select Col2=C.v.value('.','nvarchar(100)') from a.COl2.nodes('/root/v')C(v))bSQL05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 Tabunion allselect 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           a1           b1           c2           d2           e3           f*/