合并列值 原著:邹建 改编:爱新觉罗.毓华 2007-12-16 广东深圳 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) */
if object_id('A') is not null drop table A go create table A ( id int, Desc1 varchar(8) ) insert into A select 4, '容易起泡' union all select 6,'容易发毛' union all select 7,'容易粗糙' union all select 8,'容易发晦' go declare @a varchar(100) set @a='' select @a=@a+','+ Desc1 from A where ID in(4,8) select substring(@a,2,100)
原著:邹建
改编:爱新觉罗.毓华 2007-12-16 广东深圳 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)
*/
if object_id('A') is not null
drop table A
go
create table A
( id int,
Desc1 varchar(8)
)
insert into A select 4, '容易起泡'
union all select 6,'容易发毛'
union all select 7,'容易粗糙'
union all select 8,'容易发晦'
go
declare @a varchar(100)
set @a=''
select @a=@a+','+ Desc1 from A where ID in(4,8)
select substring(@a,2,100)