分析

关键词:内联结inner join

思路:

  • 分组计算订单总价。 sum(quantity*item_price) as OrderTotal group by cust_name, Orders.order_num
  • 三表联结。from Orders inner join Customers on Orders.cust_id=Customers.cust_id inner join OrderItems on Orders.order_num=OrderItems.order_num

代码

select cust_name,Orders.order_num,sum(quantity*item_price) as OrderTotal
from Orders
inner join Customers on Orders.cust_id=Customers.cust_id
inner join OrderItems on Orders.order_num=OrderItems.order_num
group by cust_name,Orders.order_num
order by cust_name asc,Orders.order_num asc