[求助]一道有点难度的sql

create table t(n varchar(10),i int)
insert t select 'a',1
union select 'b',2
union select 'b',3
union select 'c',4
union select 'c',5
union select 'c',6
select * from t
create function m(@i varchar(10))
returns varchar(200)
as
begin
declare @n varchar(2000)
set @n=''
select @n=@n+''+cast(i as varchar) from t where n=@i
return @n
end
select distinct n,dbo.m(n) as s from t

有价值
这是一种算法的锻炼

没有啊,我是新手