create FUNCTION stTable ( @id varchar(32) ) RETURNS @st TABLE (id varchar(8000)) begin declare @sql as varchar(8000); set @sql='' select @sql=@sql+','+objid2+'' from (select distinct objid2 from dbo.refobjlink where objid1=@id and linktype='project3') b set @sql=substring(@sql,2,len(@sql)) insert into @st values(@sql) return end GOupdate project set numbers=t.id from project CROSS APPLY stTable(project.id) t GO 结果是:原有多行的数据: 1 2 3 4 5 转化为一列的数据: 1,2,3,4,5
--2005直接用XMlselect stuff((select ','+rtrim(number) from spt_values where t.type=type and number<6 for xml path('')),1,1,'') from spt_values t where type='p' group by type/*---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 0,1,2,3,4,5(1 行受影响)*/
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
(
@id varchar(32)
)
RETURNS @st TABLE (id varchar(8000))
begin
declare @sql as varchar(8000);
set @sql=''
select @sql=@sql+','+objid2+''
from (select distinct objid2 from dbo.refobjlink where objid1=@id and
linktype='project3') b
set @sql=substring(@sql,2,len(@sql))
insert into @st values(@sql)
return
end
GOupdate project set numbers=t.id
from project
CROSS APPLY stTable(project.id) t
GO
结果是:原有多行的数据:
1
2
3
4
5
转化为一列的数据:
1,2,3,4,5
--2005直接用XMlselect stuff((select ','+rtrim(number) from spt_values where t.type=type and number<6 for xml path('')),1,1,'')
from spt_values t where type='p'
group by type/*----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
0,1,2,3,4,5(1 行受影响)*/
SET @str = ''
SELECT @str = @str + ',' + value FROM tb WHERE id=1
SELECt id, value = STUFF(@str, 1, 1, '') FROM tb GROUP BY id
http://topic.csdn.net/u/20091112/13/d2b27b6f-41c8-4400-b569-32ada555b99a.html
比如我表结构如下
tbUser
UserNum UserName
1 张三
2 李四
3 王五
4 赵六
我要返回UserNum<4的用户名称字符串,结果为 张三,李四,王五,用一个SQL语句怎么写?
写一个函数是不是在C#中不方便调用哦
--*******************************************************************************************
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