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 order_num from OrderItems group by order_num having sum(quantity)>=100 #where用于聚合计算前的字段筛选，having用于聚合计算后的字段筛选，如果有计算字段过滤指标，则用having 不用 where order by order_num
