采用了dense_rank和limit
商品价格排名
https://www.nowcoder.com/practice/119f5b8cfe5b45779a3e1b3f4d83b341
select
product_id,
product_name,
type,price
from
(
select
*,dense_rank()over(partition by type order by price desc) as rk
from
product_info
) t1
where rk <3
order by price desc,product_name
limit 3
