题解 | #返回订单数量总和不小于100的所有订单的订单号#
返回订单数量总和不小于100的所有订单的订单号
http://www.nowcoder.com/practice/ff77e82b59544a15987324e19488aafd
select嵌套解题
select
o.order_num
from
(select
order_num,
sum(quantity) as sumquantity
from
OrderItems
group by
order_num
)o
where
o.sumquantity >= 100
order by
o.order_num asc
，可以适当对关键信息加粗一点，比如关键技术、性能指标之类的。