/* 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') gocreate 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 iddrop 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') goselect id, [value] = stuff((select ',' + [value] from tb t where id = tb.id for xml path('')) , 1 , 1 , '') from tb group by iddrop 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_cursorselect * from @t drop table tb
---------------------------------------------------------------- -- Author :fredrickhu(小F,向高手学习) -- Date :2009-10-24 21:05:38 -- 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 5.1 (Build 2600: Service Pack 3) -- ---------------------------------------------------------------- --> 测试数据:[tb] if object_id('[tb]') is not null drop table [tb] go create table [tb]([ID] int,[field] varchar(1)) insert [tb] select 1,'a' union all select 1,'b' union all select 1,'c' union all select 2,'d' union all select 2,'e' --------------开始查询-------------------------- select id, [field] = stuff((select ',' + [field] from tb t where id = tb.id for xml path('')) , 1 , 1 , '') from tb group by id ----------------结果---------------------------- /* id field ----------- ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- 1 a,b,c 2 d,e(2 行受影响)*/
ID field 1 a 1 b 1 c 2 d 2 e 按我的理解这已经是最小冗余的查询结果了!
select id, [field] = stuff((select ',' + [field] from tb t where id = tb.id for xml path('')) , 1 , 1 , '') from tb group by id 这样子 简练,好!
create table tb (c1 int,c2 varchar(30)) go insert tb values(1,'a') insert tb values(1,'b') insert tb values(1,'c') insert tb values(2,'d') insert tb values(2,'e') gocreate function e(@c1 int) returns varchar(300) as begin declare @ch varchar(300) set @ch='' select @ch=@ch+','+c2 from tb where c1=@c1 return (stuff(@ch,1,1,'')) end go select c1,c2=dbo.e(c1) from tb group by c1
http://topic.csdn.net/u/20080612/22/c850499f-bce3-4877-82d5-af2357857872.html?23514
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')
gocreate 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 iddrop 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')
goselect id, [value] = stuff((select ',' + [value] from tb t where id = tb.id for xml path('')) , 1 , 1 , '')
from tb
group by iddrop 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_cursorselect * from @t
drop table tb
-- Author :fredrickhu(小F,向高手学习)
-- Date :2009-10-24 21:05:38
-- 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 5.1 (Build 2600: Service Pack 3)
--
----------------------------------------------------------------
--> 测试数据:[tb]
if object_id('[tb]') is not null drop table [tb]
go
create table [tb]([ID] int,[field] varchar(1))
insert [tb]
select 1,'a' union all
select 1,'b' union all
select 1,'c' union all
select 2,'d' union all
select 2,'e'
--------------开始查询--------------------------
select id, [field] = stuff((select ',' + [field] from tb t where id = tb.id for xml path('')) , 1 , 1 , '')
from tb
group by id
----------------结果----------------------------
/* id field
----------- ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1 a,b,c
2 d,e(2 行受影响)*/
1 a
1 b
1 c
2 d
2 e 按我的理解这已经是最小冗余的查询结果了!
from tb
group by id
这样子 简练,好!
go
insert tb values(1,'a')
insert tb values(1,'b')
insert tb values(1,'c')
insert tb values(2,'d')
insert tb values(2,'e')
gocreate function e(@c1 int)
returns varchar(300)
as
begin
declare @ch varchar(300)
set @ch=''
select @ch=@ch+','+c2 from tb where c1=@c1
return (stuff(@ch,1,1,''))
end
go
select c1,c2=dbo.e(c1) from tb group by c1