/* select 是指选择支付方式，只要到了选择支付方式这一步，都视为该订单计入销售额；
完整的下单流程是select选择支付方式、order下单、start开始支付、failed支付失败、end支付结束*/
select t2.product_name
,t2.sales_total
from(
select t1.product_name
,sales_total
,dense_rank() over(order by sales_total desc) as rk
from
(select product_name
,price * count(step)  as sales_total
from user_client_log u
join product_info p on u.product_id = p.product_id
where step = "select"
group by p.product_id
) t1
) t2
where rk <= 2