题解 | 确定最佳顾客的另一种方式（二）

select
    c.cust_name,
    round(sum(oi.item_price*oi.quantity),3) as total_price
from
    Orders o
    inner join OrderItems oi on o.order_num = oi.order_num
    inner join Customers c on o.cust_id = c.cust_id
group by c.cust_name
having total_price >= 1000
order by total_price
;