题解 | #计算总和#

select order_num,sum(item_price * quantity) total_price from OrderItems group by order_num having total_price>=1000 order by order_num

having 的使用是对于分组后的数据进行过滤，先有group by 然后再用having进行过滤，再对过滤后的数据进行排序，group by -having -order by