CREATE TABLE tb(col1 varchar(10),col2 int)
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3CREATE FUNCTION dbo.f_str(@col1 varchar(10))
RETURNS varchar(100)
AS
BEGIN
DECLARE @re varchar(100)
SET @re=''
SELECT @re=@re+','+CAST(col2 as varchar)
FROM tb
WHERE col1=@col1
RETURN(STUFF(@re,1,1,''))
END
GO
SELECT col1,col2=dbo.f_str(col1) FROM tb GROUP BY col1/*
col1 col2
---------- -----------
a 1,2
b 1,2,3
*/
INSERT tb SELECT 'a',1
UNION ALL SELECT 'a',2
UNION ALL SELECT 'b',1
UNION ALL SELECT 'b',2
UNION ALL SELECT 'b',3CREATE FUNCTION dbo.f_str(@col1 varchar(10))
RETURNS varchar(100)
AS
BEGIN
DECLARE @re varchar(100)
SET @re=''
SELECT @re=@re+','+CAST(col2 as varchar)
FROM tb
WHERE col1=@col1
RETURN(STUFF(@re,1,1,''))
END
GO
SELECT col1,col2=dbo.f_str(col1) FROM tb GROUP BY col1/*
col1 col2
---------- -----------
a 1,2
b 1,2,3
*/
的效果
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')
goCREATE 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 iddrop 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 tbdrop 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')
goselect 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
create function f_hb(@IP1 varchar(10),@ip2 varchar(10), @name varchar(10) , @pwd varchar(10) )
returns varchar(8000)
as
begin
declare @str varchar(8000)
set @str = ''
select @str = @str + ',' + cast(kkk as varchar) from tb where ip1 = @IP1 and ip2 = @ip2 and name = @name and pwd = @pwd
set @str = right(@str , len(@str) - 1)
return(@str)
End
go--调用自定义函数得到结果:
select distinct ip1 , ip2 , name , pwd ,dbo.f_hb(ip1 , ip2 , name , pwd) as kkk from tb
函数改成两个参数
IP1 NAME
drop table tb
go
create table tb(IP1 varchar(10), ip2 varchar(10), name varchar(10), pwd int,kkk varchar(10))
insert tb select 'a1', 'a2', 'aaa', 111, 'a'
insert tb select 'a1', 'a2', 'aaa', 111, 'b'
insert tb select 'a1', 'a2', 'aaa', 111, 'c'
insert tb select 'b1', 'b2', 'bbb', 111, 'd'
insert tb select 'b1', 'b2', 'bbb', 111, 'e'
insert tb select 'b1', 'b2', 'ccc', 111, 'f'
if object_id('dbo.f_str')is not null
drop function dbo.f_str
go
CREATE FUNCTION dbo.f_str(@IP1 varchar(10),@Name varchar(10))
RETURNS varchar(1000)
AS
BEGIN
DECLARE @re varchar(100)
SET @re=''
SELECT @re=@re+','+CAST(KKK as varchar)
FROM tb
WHERE IP1=@IP1 and Name=@Name
RETURN(STUFF(@re,1,1,''))
END
go
select IP1, ip2, name, pwd, dbo.f_str(IP1,Name)kkk from tb t where not exists(select 1 from tb where name=t.name and ip1=t.ip1 and kkk<t.kkk)
---------------------------------------------------
IP1 ip2 name pwd kkka1 a2 aaa 111 a,b,c
b1 b2 bbb 111 d,e
b1 b2 ccc 111 f