关于查询的SQL语句,在线等~~
有两张表,主表和从表。主表一对多对应从表。sqlserver能不能用一条语句查询出格式为
select 主表列1,主表列2,从表数据(多条,用逗号或者其他符号分割开) from。。。。
就是: select 主表1,主表2,(从表1,从表1,从表1) from 主表
主表和从表是一对多,就要从表对应多条的列合并。
我就是希望从表这把多条数据用逗号分割合并成一条数据。
等高人指点~
[解决办法]
--这个?/****************************************************************************************************************************************************** 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) */ --参考拆分表:--> --> (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'Go--SQL2000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)=','--2000不使用辅助表Select a.Col1,COl2=substring(a.Col2,b.number,charindex(',',a.Col2+',',b.number)-b.number) from Tab a join master..spt_values b ON B.type='p' AND B.number BETWEEN 1 AND LEN(A.col2)where substring(','+a.COl2,b.number,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*/