获取记录的行号
--2005
select rn=row_number()over(order by 专业号),* from tb
--2000
select rn=(select count(1) from tb where 专业号<=t.专业号),* from tb t
--2005
select rn=row_number()over(order by 专业号),* from tb
--2000
select rn=(select count(1) from tb where 专业号<=t.专业号),* from tb t