题解 | #返回产品名称和每一项产品的总订单数#
返回产品名称和每一项产品的总订单数
http://www.nowcoder.com/practice/1c64fd9048364a58a8ffa541720359a4
select prod_name,ifnull(orders,0)
from Products p
left join (select prod_id, count(order_num) as orders from OrderItems group by prod_id) o
on p.prod_id=o.prod_id
order by prod_name
查看20道真题和解析