ql server 表中如何把ID相同的行的同一个字段值合起来放到另一个字段中。

[Gold_1010]

如题

表A
ID STID tag
1 1 11
2 1 2
3 2 23
4 3 12
5 3 11
... ... ...

查询后
STID num
1 11,2
2 23
3 12,11

[Gold_1010]

查询后 的表的第二个字段应该是tag 手误

[唐诗三百首]

create table 表A
(ID int,STID int,tag int)

insert into 表A
 select 1,1,11 union all
 select 2,1,2 union all
 select 3,2,23 union all
 select 4,3,12 union all
 select 5,3,11


select STID,
       tag=stuff((select ','+rtrim(b.tag) 
                   from 表A b 
                   where b.STID=a.STID
                   for xml path('')),1,1,'')
 from 表A a
 group by STID
 order by STID

/*
STID        tag
----------- -----------
1           11,2
2           23
3           12,11

(3 row(s) affected)
*/

[Gold_1010]

引用 2 楼 ap0405140 的回复:

create table 表A
(ID int,STID int,tag int)

insert into 表A
 select 1,1,11 union all
 select 2,1,2 union all
 select 3,2,23 union all
 select 4,3,12 union all
 select 5,3,11


select STID,
       tag=stuff((select ','+rtrim(b.tag) 
                   from 表A b 
                   where b.STID=a.STID
                   for xml path('')),1,1,'')
 from 表A a
 group by STID
 order by STID

/*
STID        tag
----------- -----------
1           11,2
2           23
3           12,11

(3 row(s) affected)
*/

感谢，我配合自己的表试一下