题解 | #某宝店铺折扣率#
某宝店铺折扣率
https://www.nowcoder.com/practice/3a56f160308441f5a79d8ac8d953e5e7
select round(sum(sales_price)*100/sum(tag_price*sales_num),2) as `discount_rate(%)` #如果别名中有特殊字符需要增加引号或者`` from product_tb join sales_tb using (item_id) where left(sales_date,7) = '2021-11'
本体难度不大,sales_price已经是总体价格了在sum()中不需要在与sales_num相乘