题解 | 确定最佳顾客的另一种方式（二）
select
cust_name,
sum(total_price) total_price
from
(
select
cust_name,
item_price * quantity total_price
from
OrderItems ori
join Orders ord on ori.order_num = ord.order_num
join Customers cus on ord.cust_id = cus.cust_id
) a
group by
cust_name
having
total_price >= 1000
order by
total_price
