sql 查询统计语句

[shuogu]

现有如下格式的表格
ID field
1 a
1 b
1 c
2 d
2 e
如何得到如下格式
ID field
1 a,b,c
2 d,e

谢谢大家，本人菜鸟还请见谅

[SQL77]

合并分拆表：
http://topic.csdn.net/u/20080612/22/c850499f-bce3-4877-82d5-af2357857872.html?23514

[liangCK]

不会.

[dawugui]

/*
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

[zzh_scxh]

在查询里面做，不过不要忘了按ID分组就可以了。

[--小F--]

----------------------------------------------------------------
-- 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)

*/

[feixianxxx]

[Quote=引用 3 楼 liangck 的回复:]
不会.
[/Quote]

[战斗生活]

干嘛要这样你呢

在显示页面修改不就得拉吗

[jiaoyanan]

学习了

[无牛刀]

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！

[dyeerp]

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')
go

create 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

[cmdgjw]

按我的理解这已经是最小冗余的查询结果了！

[cmdgjw]

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！