[求助]在另一个编程论坛中发现的一个问题，想咨询一下大家！

你的电脑打过补丁没,应该是sql server的一个bug,以前就看到有人在操作自带的数据库的时候出现奇怪问题.我模拟了一下没出现那奇怪现象
if object_id('student') is not null
drop table student
go
create table student(id int,name varchar(20))
insert into student select 1,'aa'
insert into student select 1,'bb'

declare @str varchar(100)
select @str=''
select @str=@str+name+'-' from student where id=1
print @str

declare @str varchar(100)
select @str=''
select @str=@str+name+'-' from student where id=1 order by id
print @str

declare @str varchar(100)
select @str=''
select @str=@str+name+'-' from (select top 50 percent name from student where id=1 order by id desc) s
print @str

declare @str varchar(100)
select @str=''
select @str=@str+name+'-' from (select top 100 percent name from student where id=1 order by id desc) s
print @str