题解 | #某宝店铺折扣率#字段中存在特殊符号，用‘’
某宝店铺折扣率
https://www.nowcoder.com/practice/3a56f160308441f5a79d8ac8d953e5e7
select round(sum(sales_price)/sum(tag_price*sales_num)*100, 2) as 'discount_rate(%)'
from (
select a.item_id, a.tag_price, b.sales_num, b.sales_price
from product_tb as a
left join sales_tb as b
on a.item_id = b.item_id
) as c;
