sql - 获取sql中不同的记录

Question

我编写了以下查询来获取客户电子邮件地址、订单计数(即客户下了多少订单)、订单的总价。但我得到了重复的结果。

我想要有不同的记录，例如:

Customer A, 5 orders, $125 total
Customer B, 2 orders, $150 total

but i am getting the results like:

Customer A, 4 orders, $100 total
Customer A, 1 order, $25 total
Customer B, 1 order, $100 total
Customer B, 1 order, $50 total

Can you please help me how can i get the result as i want. I have written the following Query:

    Select 
    customers.CustomerID,
    customers.EmailAddress,
    COUNT(Orders.OrderID) AS Ordercount,
    Sum(OrderDetails.TotalPrice * OrderDetails.Quantity) AS TotalPrice 
from 
    customers 
    INNER JOIN Orders ON customers.CustomerID = Orders.CustomerID 
    INNER JOIN OrderDetails ON OrderDetails.OrderID = Orders.OrderID 
GROUP BY 
    customers.CustomerID,
    customers.EmailAddress,
    Orders.OrderID,
    OrderDetails.TotalPrice,
    OrderDetails.Quantity 
ORDER BY customers.CustomerID, orders.OrderID desc

Answer 1

您只需对选择中的字段进行分组，而不是 COUNT 或 SUM 的一部分

Select 
    customers.CustomerID,
    customers.EmailAddress,
    COUNT(Orders.OrderID) AS Ordercount,
    Sum(OrderDetails.TotalPrice * OrderDetails.Quantity) AS TotalPrice 
from 
    customers 
    INNER JOIN 
    Orders ON customers.CustomerID = Orders.CustomerID 
    INNER JOIN 
    OrderDetails ON OrderDetails.OrderID = Orders.OrderID 
GROUP BY 
    customers.CustomerID,
    customers.EmailAddress
ORDER BY 
    customers.CustomerID desc