以下的文章主要向大家描述的是SQL server合并分拆表的实际操组方法的描述，本文是以SQL server合并分拆表的实际操作的应用代码的方式来引出其实际操作步骤，以下就是文章的主要内容描述。
合并分拆表
(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(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) */
以上的相关内容就是对SQL server合并分拆表的方法的介绍，望你能有所收获。