--sql 2000
select 序号 = (select count(1) from tb where 学号 < t.学号) + 1,学号 ,姓名 from tb t

 
--sql 2005
select 序号 = row_number() over(order by 学号),学号 ,姓名 from tb

 
--oracle
select row_number() over(order by 学号) 序号,学号 ,姓名 from tb
--postsql
SELECT ROW_NUMBER () OVER ( ORDER BY A0 DESC,B0 DESC,C0 DESC ) AS rid ,* FROM t_road WHERE A0 = 'X' ORDER BY A0, B0,C0 ;