Question

这是我的代码：

SELECT Discount,
       country,
       count(country) AS total
FROM   OrderDetails,
       Customers
WHERE  discount != 0
GROUP  BY Discount,
          country
HAVING ( count(country) > 0 )
ORDER  BY discount DESC

我现在需要做的是，无法在任何地方找到，就是让计数（国家/地区）加上正确的折扣数字。这样我知道每个国家有多少折扣。我到处寻找，我找不到任何东西。即使在我自己的论文中，我也是从学校毕业的。

所以这是带连接的代码，所以看一下它会更清楚：

select Discount, country, count(country) as total
from Orders O
join Customers C
on C.CustomerID = O.CustomerID
join OrderDetails OD
on OD.OrderID = O.OrderID
where discount != 0
group by Discount, country
having (count(country)>0)
order by discount DESC

Answer 1

select c.country, sum(od.discount)   as totalDiscount
from orders o
inner join customers c
on c.customerID = o.customerID
inner join orderDetails od
on od.orderID = o.orderID
where od.discount != 0
group by c.country
order by sum(od.discount) desc

我需要在正确的国家/地区计算适量的折扣，我该怎么做？

1 个答案: