题解 | #某宝店铺折扣率#
某宝店铺折扣率
https://www.nowcoder.com/practice/3a56f160308441f5a79d8ac8d953e5e7
坑点：标签日期需要乘以销量，或者订单价除以销量
select
round(sum(sales_price)/sum(tag_price*sales_num)*100,2) as 'discount_rate(%)'
from sales_tb s join product_tb p using(item_id)
