select
    Customers.cust_name as cust_name,
    Orders.order_num as order_num,
    OrderItems.quantity*OrderItems.item_price as OrderTotal
from
    Orders
join Customers on Customers.cust_id=Orders.cust_id
join OrderItems on Orders.order_num=OrderItems.order_num
order by
    cust_name,order_num;