求 一条Access SQL 语句， 得到 【结果】表。

select 序号,row_number() over (partition by 班级 order by 成绩) as 班名次,row_number() over (order by 成绩) as 级名次 from T1

晕，我忘了你的是Access，Access没有row_number()函数
access比较难写，也比较难看懂，认真看，这句应该可行的：
select 序号,(select count(*) from T1 as a where a.成绩>=c.成绩 and a.班级=c.班级) as 班名次,(select count(*) from T1 as b where b.成绩>=c.成绩) as 级名次 from T1 as c

再次晕倒，还有并列名次的问题，不过这难不倒我，以上查询改成：
select 序号,(select count(*)+1 from T1 as a where a.成绩>c.成绩 and a.班级=c.班级) as 班名次,(select count(*)+1 from T1 as b where b.成绩>c.成绩) as 级名次 from T1 as c

花了点时间测试：通过