Question

我有四个表，但为此我只需要三个表，并且我想显示customerid，orderid，productid，quantity和总成本，这些不在任何表中但需要计算？到目前为止，我已设法使用订单ID显示一个订单的总成本，但我希望它显示上面提到的所有列

顺序：

order_id(primary key)
customer_id( foreign key)

订单项目：

orderid(fk) + productid(fk) (pk)
quantity

产品：

productid(pk)
price

我所做的是

select orderid, sum(rowcost) as totalcost
  from (select o.quantity, o.productid, o.orderid, os.customerid, p.price, 
              (o.quantity * p.price) as rowcost
         from orderline o 
              inner join order os 
                      on o.orderid = os.orderid 
              inner join product p 
                      on p.productid = o.productid 
         where productid = 123) 
 group by orderid;

现在我希望它显示所有orderid以及productid，customerid，totalcost，orderid和quantity。该列表应遵循customerid订单。

我该怎么做？

当我在select中添加更多变量时，它会给我带来错误。我尝试了很多方法，但都没有。

Answer 1

你是说你想要这样的东西：

select o.quantity, o.productid, o.orderid, os.customerid, p.price, 
       (o.quantity * p.price) as rowcost,
       sum(o.quantity * p.price) over (partition by os.customerid) as totalcost
  from orderline o 
       inner join order os 
               on o.orderid = os.orderid 
       inner join product p 
               on p.productid = o.productid 
 where p.productid = 123

或者，如果你想在产品上过滤后保持总和正确

select *
  from (select o.quantity, o.productid, o.orderid, os.customerid, p.price, 
               (o.quantity * p.price) as rowcost,
               sum(o.quantity * p.price) over (partition by os.customerid) as totalcost
          from orderline o 
               inner join order os 
                       on o.orderid = os.orderid 
               inner join product p 
                       on p.productid = o.productid)
 where productid = 123--or just remove this where clause

小提琴：http://sqlfiddle.com/#!4/3103d/1

如何从多个表中选择多个列以及总成本？

1 个答案: