格式转换

[xubingjingme]

原数据
name project
a 1
a 2
a 3
b 1
b 2
a 3


是否可以变成

name project
a 1,2,3
b 4,5,6

[gw6328]

楼主这是什么变化，太大了吧！两个b的整成3个去了？还是什么情况？

[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 varchar(10)) returns varchar(1000)
as
begin
  declare @str varchar(1000)
  select @str = isnull(@str + ',' , '') + cast(value as varchar) from tb where id = @id
  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

[--小F--]

B的是 4,5,6?

[dawugui]

--sql 2000
create function dbo.f_str(@name varchar(10)) returns varchar(1000)
as
begin
declare @str varchar(1000)
select @str = isnull(@str + ',' , '') + cast(project as varchar) from tb where name = @name
return @str
end
go

--调用函数
select name , project = dbo.f_str(name) from tb group by name

--sql 2005
select name, project = stuff((select ',' + [project] from tb t where name = tb.name for xml path('')) , 1 , 1 , '')
from tb
group by name

[晓蛋]

太诡异了 佩服楼主的跳跃思维。。。

[xubingjingme]

不好意思
b是4,5,6

[areswang]

create table tb(name varchar(20),project int)
go
insert into tb select 'a',1
insert into tb select 'a',2
insert into tb select 'a',3
insert into tb select 'b',4
insert into tb select 'b',5
insert into tb select 'b',6

select name,STUFF((select  ','+cast(project as varchar(20)) from tb where name=t.name for xml path('')),1,1,'') project
from tb t
group by name
--
name	project
a	1,2,3
b	4,5,6

[q465897859]

[Quote=引用 7 楼 areswang 的回复:]
SQL code

create table tb(name varchar(20),project int)
go
insert into tb select 'a',1
insert into tb select 'a',2
insert into tb select 'a',3
insert into tb select 'b',4
insert into tb select……
[/Quote]+1

[gw6328]

declare @tb table(name varchar(20),project int)

insert into @tb select 'a',1
insert into @tb select 'a',2
insert into @tb select 'a',3
insert into @tb select 'b',1
insert into @tb select 'b',2
insert into @tb select 'b',3

update @tb set project+=3 where name='b' --楼主不是真的要加吧- -！
select name,STUFF((select  ','+cast(project as varchar(20)) from @tb where name=t.name for xml path('')),1,1,'') project
from @tb t
group by name