sql中怎样把同一张表中相同字段的内容合并为一条记录(合并的记录的后面不加逗号)？

一、创建表

create table stuUnion
(
 sid int identity primary key,
 cid int,
 id varchar(500)
)

 

二、添加数据

insert into stuUnion
select 1,'a' union
select 1,'b' union
select 2,'c' union
select 2,'d' union
select 3,'e' union
select 3,'f' union
select 3,'g'

 

三1、用标量函数查询

     (1)创建标量函数

create function r(@cid int )
returns varchar(100)
as
begin
 declare @s varchar(100)
 select @s=isnull(@s+',','')+rtrim(id) from stuUnion where cid=@cid
 return @s
end;

  (2)用标量函数查询

select cid,dbo.r(cid) AS id from stuUnion group by cid

三2、用sqlserver的xml

select cid,ID=STUFF((select ','+rtrim(id) from stuUnion where st.cid=cid order by id for XML path('')),1,1,'') from stuUnion st group by cid