1 取出分数前十名
select * from (select id,score from b order by score desc) where rownum<=10;
2 将第一步的结果集命名为表c和表a通过id进行关联,取出表a的name
select a.id,c.name,c.score from a,(select * from (select id,score from b order by score desc) where rownum<=10) c where a.id=c.id;
select top 10 name from a,b where a.id=b.id order by b.score desc