求助一个sql分组统计问题

if object_id('tb3') is not null

drop table tb3



create table tb3

( 分组名称 varchar(6),

标记号 varchar(6),

分类 varchar(6),

数量 int) 



insert into tb3

select '分组1','AA-1','分类1',10 union all

select '分组1','AA-2','分类1',20 union all

select '分组2','BB-1','分类1',30 union all

select '分组2','BB-2','分类2',10 union all

select '分组2','BB-3','分类2',20 union all

select '分组2','BB-4','分类2',20 union all

select '分组2','BB-4','分类3',10 





select 分组名称,stuff((select ','+标记号 from tb3 where a.分组名称=分组名称 and 分类=a.分类 for xml path('')),1,1,'') as 标记号,分类,sum(数量) as 数量

from tb3 a

group by 分组名称,分类

/*

标题：按某字段合并字符串之一(简单合并)

作者：爱新觉罗.毓华(十八年风雨,守得冰山雪莲花开)

时间：2008-11-06

地点：广东深圳



描述：将如下形式的数据按id字段合并value字段。

id    value

----- ------

1     aa

1     bb

2     aaa

2     bbb

2     ccc

需要得到结果：

id     value

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

1      aa,bb

2      aaa,bbb,ccc

即：group by id, 求 value 的和（字符串相加）

*/

--1、sql2000中只能用自定义的函数解决

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



create function dbo.f_str(@id int) returns varchar(100)

as

begin

    declare @str varchar(1000)

    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



--调用函数

select id , value = dbo.f_str(id) from tb group by id



drop function dbo.f_str

drop table tb





--2、sql2005中的方法

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, [value] = stuff((select ',' + [value] from tb t where id = tb.id for xml path('')) , 1 , 1 , '')

from tb

group by id



drop table tb





--3、使用游标合并数据

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

declare @t table(id int,value varchar(100))--定义结果集表变量

--定义游标并进行合并处理

declare my_cursor cursor local for

select id , value from tb

declare @id_old int , @id int , @value varchar(10) , @s varchar(100)

open my_cursor

fetch my_cursor into @id , @value

select @id_old = @id , @s=''

while @@FETCH_STATUS = 0

begin

    if @id = @id_old

       select @s = @s + ',' + cast(@value as varchar)

    else

      begin

        insert @t values(@id_old , stuff(@s,1,1,''))

        select @s = ',' + cast(@value as varchar) , @id_old = @id

      end

    fetch my_cursor into @id , @value

END

insert @t values(@id_old , stuff(@s,1,1,''))

close my_cursor

deallocate my_cursor



select * from @t

drop table tb

合并列值 

--*******************************************************************************************

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。) 

--=============================================================================

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 

--1. 创建处理函数 

CREATE FUNCTION dbo.f_strUnite(@id int) 

RETURNS varchar(8000) 

AS 

BEGIN 

    DECLARE @str varchar(8000) 

    SET @str = '' 

    SELECT @str = @str + ',' + value FROM tb WHERE id=@id 

    RETURN STUFF(@str, 1, 1, '') 

END 

GO 

-- 调用函数 

SELECt id, value = dbo.f_strUnite(id) FROM tb GROUP BY id 

drop table tb 

drop function dbo.f_strUnite 

go

/* 

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