记录合并

psusjh 2009-09-16 04:20:21

合并前
字段1 as a, 字段2 as b
1 a
1 b
1 c
1 d
2 e
2 f
2 g

合并后
1 a;b;c;d;
2 e;f;g

只用一条SQL语句,怎么实现

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htl258_Tony 2009-09-16

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[Quote=引用 5 楼 psusjh 的回复:]
不用创建表,只用一条一句
[/Quote]
几个楼层都有你要的。

--小F-- 2009-09-16

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--2005里面才可以的

select distinct a,b=STUFF((SELECT ';'+b FROM tb WHERE a=T.a FOR XML PATH('')),1,1,'') FROM tb t

psusjh 2009-09-16

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不用创建表,只用一条一句

--小F-- 2009-09-16

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

-- Author  :fredrickhu(我是小F，向高手学习)

-- Date    :2009-09-16 16:27:25

-- Version:

--      Microsoft SQL Server 2005 - 9.00.4035.00 (Intel X86) 

--	Nov 24 2008 13:01:59 

--	Copyright (c) 1988-2005 Microsoft Corporation

--	Developer Edition on Windows NT 5.2 (Build 3790: Service Pack 1)

--

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

--> 测试数据：[tb]

if object_id('[tb]') is not null drop table [tb]

go 

create table [tb]([col1] int,[col2] varchar(1))

insert [tb]

select 1,'a' union all

select 1,'b' union all

select 1,'c' union all

select 1,'d' union all

select 2,'e' union all

select 2,'f' union all

select 2,'g'

--------------开始查询--------------------------

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

as

begin

    declare @str varchar(1000)

    set @str = ''

    select @str = @str + ';' + cast(col2 as varchar) from tb where col1 = @id

    set @str = right(@str , len(@str) - 1)

    return @str

end

go



--调用函数

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



drop function dbo.f_str

drop table tb



----------------结果----------------------------

/* col1        col2

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

1           a;b;c;d

2           e;f;g



(2 行受影响)

*/

JonasFeng 2009-09-16

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CREATE TABLE tb1(col1 varchar(10),col2 varchar(10))

INSERT tb1 SELECT '1','a'

UNION ALL SELECT '1','b'

UNION ALL SELECT '1','c'

UNION ALL SELECT '1','d'

UNION ALL SELECT '2','e'

UNION ALL SELECT '2','f'

UNION ALL SELECT '2','g'

Go 



--合并处理

SELECT distinct col2=stuff((select ';'+col2 from tb1 where col1=t.col1 for xml path('')),1,1,''),col1 from tb1 t

htl258_Tony 2009-09-16

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/*---------------------------------

--  Author : htl258(Tony)

--  Date   : 2009-09-16 16:21:21

--  Version: Microsoft SQL Server 2008 (SP1) - 10.0.2531.0 (Intel X86) 

	Mar 29 2009 10:27:29 

	Copyright (c) 1988-2008 Microsoft Corporation

	Enterprise Evaluation Edition on Windows NT 5.1 <X86> (Build 2600: Service Pack 2)



---------------------------------*/

--> 生成测试数据表:tb



IF NOT OBJECT_ID('[tb]') IS NULL

	DROP TABLE [tb]

GO

CREATE TABLE [tb]([a] INT,[b] NVARCHAR(10))

INSERT [tb]

SELECT 1,'a' UNION ALL

SELECT 1,'b' UNION ALL

SELECT 1,'c' UNION ALL

SELECT 1,'d' UNION ALL

SELECT 2,'e' UNION ALL

SELECT 2,'f' UNION ALL

SELECT 2,'g'

GO

--SELECT * FROM [tb]



-->SQL查询如下:

SELECT DISTINCT a,b=STUFF((SELECT ';'+b FROM tb WHERE a=T.a FOR XML PATH('')),1,1,'') FROM tb t

/*

a           b

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

1           a;b;c;d

2           e;f;g



(2 行受影响)

*/

dawugui 2009-09-16

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/*

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