select c.cust_name cust_name,o.order_num,t.OrderTotal as OrderTotal from Customers c join Orders o on c.cust_id=o.cust_id join (select order_num,ROUND(sum(quantity*item_price),3) as OrderTotal from OrderItems group by order_num) t on t.order_num=o.order_num order by c.cust_name,t.OrderTotal asc 关联查询...

select order_num,sum(item_price*quantity) as total_prrice from OrderItems group by order_num having total_prrice>=1000

select t.order_num from (select order_num,sum(quantity) as hz from OrderItems group by order_num having hz>=100 ) t order by t.order_num 简单