sql server多行数据拼接的实例方法

1.表结构
id type productcode
1 铅笔 0001
2 铅笔 0002
3 铅笔 0003
4 钢笔 0004
5 钢笔 0005
6 钢笔 0004
7 圆珠笔 0007
8 圆珠笔 0008
9 圆珠笔 0007
2.自定义函数fun

go
/****** object:  userdefinedfunction [dbo].[fun]    script date: 11/22/2011 16:09:45 ******/
set ansi_nulls on
go
set quoted_identifier on
go
create function [dbo].[fun](@type nvarchar(10))
returns nvarchar(200)
as
begin
    declare @re nvarchar(200)
    declare @code nvarchar(200)
    set @re=''
    set @code=''
    select @re=@re+productcode+',' from t where type=@type group by productcode
    select @re=left(@re, len(@re)-1)
    return @re
end

3.查询语句
select type,dbo.fun(type) from (select distinct type from t) a
结果:
钢笔   0004,0005
铅笔   0001,0002,0003
圆珠笔   0007,0008