排名的 SQL 查询

可以使用自连接执行排名，该自连接计算将获得相同或较低排名的项目数。此想法在以下销售统计示例中实施。

create table sales (product int primary key, revenue int);

select product, revenue,
       (select count(*)
        from sales s1 where s1.revenue <= s2.revenue) as rank
from sales s2
order by rank asc