题解 | 返回顾客名称和相关订单号以及每个订单的总价

select
t1.cust_name  cust_name
,t2.order_num order_num
,t3.quantity * t3.item_price OrderTotal 
from Customers t1
join Orders t2 on t1.cust_id = t2.cust_id 
join OrderItems t3 on t2.order_num = t3.order_num
order by 1,2