在SQL中如何把组合字段

[roony]

当我查询出一个结果之后：
col1 col2 col3
2 3 4
2 3 5
2 3 6
而我想要的结果是:
col1 col2 col3
2 3 4,5,6

请各位大侠解惑！
（在oracle中好像用wmsys.wm_concat、sys_connect_by_path这两个函数都可以实现）

[lihan6415151528]

精华帖里面有

[htl258_Tony]

---------------------------------
--  Author: htl258(Tony)
--  Date  : 2009-07-10 11:24:10
---------------------------------
--> 生成测试数据表:tb

If not object_id('[tb]') is null
	Drop table [tb]
Go
Create table [tb]([col1] int,[col2] int,[col3] int)
Insert tb
Select 2,3,4 union all
Select 2,3,5 union all
Select 2,3,6
Go
--Select * from tb

-->SQL查询如下:
select col1,col2,
	stuff((select ','+ltrim(col3) from tb where col1=t.col1 and col2=t.col2 for xml path('')),1,1,'') col3 
from tb t
group by col1,col2

/*
col1        col2        col3
----------- ----------- ------------
2           3           4,5,6

(1 行受影响)
*/

[liangCK]

N多了.不想贴了..谁贴.

[you_tube]

在精华贴里找

[jwdream2008]

SELECT *
FROM(
    SELECT DISTINCT 
        col1,col2
    FROM @t
)A
OUTER APPLY(
    SELECT 
        [col3]= STUFF(REPLACE(REPLACE(
            (
                SELECT col2 FROM @t N
                WHERE col1 = A.col1
                And  col2=A.col2
                FOR XML AUTO
            ), '', ''), 1, 1, '')
)N

[jiangshun]

--> 测试时间：2009-07-10
--> 我的淘宝：http://shop36766744.taobao.com/

if object_id('[tab]') is not null drop table [tab]
create table [tab]([col1] int,[col2] int,[col3] int)
insert [tab]
select 2,3,4 union all
select 2,3,5 union all
select 2,3,6

select * from [tab]


create function dbo.f_str(@id int) returns varchar(100)
as
begin
    declare @str varchar(1000)
    select @str = isnull(@str + ',' ,'')+ cast(col3 as varchar) from tab where col1 = @id
    return @str
end
go

select col1,col2,dbo.f_str(col1) from tab group by col1,col2

/*
col1        col2                                                                                                             
----------- ----------- ---------------------------------------------------------------------------------------------------- 
2           3           4,5,6

（所影响的行数为 1 行）
*/

[lihan6415151528]

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。) 
--1. 创建处理函数 
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 

CREATE FUNCTION dbo.f_str(@id int) 
RETURNS varchar(8000) 
AS 
BEGIN 
    DECLARE @r varchar(8000) 
    SET @r = '' 
    SELECT @r = @r + ',' + value FROM tb WHERE id=@id 
    RETURN STUFF(@r, 1, 1, '') 
END 
GO 

-- 调用函数 
SELECt id, value = dbo.f_str(id) FROM tb GROUP BY id 

drop table tb 
drop function dbo.f_str 

/* 
id          value      
----------- ----------- 
1          aa,bb 
2          aaa,bbb,ccc 
（所影响的行数为 2 行） 
*/ 

--2、另外一种函数. 
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 

--创建一个合并的函数 
create function f_hb(@id int) 
returns varchar(8000) 
as 
begin 
  declare @str varchar(8000) 
  set @str = '' 
  select @str = @str + ',' + cast(value as varchar) from tb where id = @id 
  set @str = right(@str , len(@str) - 1) 
  return(@str) 
End 
go 

--调用自定义函数得到结果： 
select distinct id ,dbo.f_hb(id) as value from tb 

drop table tb 
drop function dbo.f_hb 

/* 
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 

[--小F--]

/****************************************************************************************************************************************************** 
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) 
*/

[feixianxxx]

-- =========================================
-- -----------t_mac 小编-------------
   ---希望有天成为大虾---- 
-- =========================================

IF OBJECT_ID('tb') IS NOT NULL
  DROP TABLE tb
GO
CREATE TABLE tb(col1 int ,col2 int, col3 int)
go
insert into tb
select 2,3,4 union all
select 2,3,5 union all
select 2,3,6 
go
create function dbo.kktt(@id1 int,@id2 int)
returns varchar(100)
as 
begin 
    declare @s varchar(100)
    set @s=''
    select @s=@s+','+cast(col3 as varchar) from tb where col1=@id1 and col2=@id2
    return stuff(@s,1,1,'')
   end
   select col1,col2,dbo.kktt(col1,col2) as col3
   from tb 
   group by col1,col2
/*------------
col1        col2        col3
----------- ----------- ----------------------------------------------------------------------------------------------------
2           3           4,5,6
-------*/

[roony]

多谢楼上各位~