题解 | #某宝店铺动销率与售罄率#

select 
    style_id,
    round(100*sum(num)/(sum(inventory)-sum(num)),2),
    round(100*sum(price)/sum(tag_price*inventory),2)
from
    product_tb as a
	--这里连表的时候要注意为了外层计算准确，要保证连表后行数不变从而保证ABC的实际库存不会多算或者少算
left join(
    select 
        item_id,
        sum(sales_num) as num,
        sum(sales_price) as price
    from 
        sales_tb
    group by 1) as b 
on a.item_id = b.item_id
group by 1
order by  style_id