题解 | #某宝店铺动销率与售罄率#

一开始没能明白啥事SPU有销售和在售的意思，后来看了大家的解释知道是 售出数/库存剩余，才明白了意思 唯一值得注意的就是，在计算product_tb中的库存和库存代换金额的时候，因为关联导致的多行，不能直接求和，需要除一下行数

``` select style_id,round((sum(already_sale)/sum(not_sale))*100,2) as `pin_rate(%)`,
round((sum(total_sale)/sum(total_tag))*100,2) as `sell-through_rate(%)`
from  (select style_id,item_id,
	sum(sales_num) as already_sale,
	sum(inventory)/count(1) - sum(sales_num) as not_sale,
	ifnull(sum(sales_price),0) as total_sale,
	sum(tag_price*inventory)/count(1) as total_tag
from sales_tb b
	right join product_tb a using(item_id)
	 group by 1,2
) a
group by 1
order by 1