35.返回每个顾客不同订单的总金额 我们需要一个顾客 ID

select cust_id,sum(item_price*quantity) total_ordered
from OrderItems a right join Orders b
on a.order_num=b.order_num
group by cust_id
order by total_ordered asc

select cust_id,avg(item_price*quantity) total_ordered
from OrderItems a right join Orders b
on a.order_num=b.order_num
group by cust_id
order by total_ordered desc

select cust_id,sum(item_price*quantity) total_ordered
from OrderItems a right join Orders b
on a.order_num=b.order_num
group by cust_id
order by total_ordered desc

select *
from (OrderItems inner join Orders
using(order_num))