Question

根据提取客户姓名和电话号码的特定搜索条件生成自动呼叫列表。

共有4个表：Customer，Phone_Numbers，Sales_Header，Sales_Detail。

查询如下：

SELECT CONCAT(customer.First_Name, ‘’, customer.Last_Name), 
       Phone_Numbers.Number, 
       Customer.ID 
FROM Sales_Header 
INNER JOIN Sales_Detail ON Sales_Detail.Header_ID = Sales_Header.ID 
INNER JOIN Customer ON Customer.ID = Sales_Header.Customer_ID 
INNER JOIN Phone_Numbers ON Phone_Numbers.Customer_ID = Customer.ID 
WHERE Sales_Header.WebSale = -1 
  AND Sales_Detail.Price > 1000 
  AND DateSold > 20081002

问题：

sales_header中的每个销售都有一个商店位置（销售它的商店的ID）。但是，顾客可以从多个商店购买。我需要找出客户花费最多的商店，并将该商店添加到上面的select语句输出中。

Answer 1

如果您使用的是MySQL，我相信它是：

SELECT CONCAT(customer.First_Name, ‘’, customer.Last_Name), 
       Phone_Numbers.Number, 
       Customer.ID, Sales_Detail.ID, Sum(Sales_Detail.Price) 
FROM Sales_Header 
INNER JOIN Sales_Detail ON Sales_Detail.Header_ID = Sales_Header.ID 
INNER JOIN Customer ON Customer.ID = Sales_Header.Customer_ID 
INNER JOIN Phone_Numbers ON Phone_Numbers.Customer_ID = Customer.ID 
WHERE Sales_Header.WebSale = -1 
  AND Sales_Detail.Price > 1000 
  AND DateSold > 20081002
GROUP BY CONCAT(customer.First_Name, ‘’, customer.Last_Name), 
       Phone_Numbers.Number, 
       Customer.ID, Sales_Detail.ID
ORDER BY Sum(Sales_Detail.Price) Desc Limit 1;

在SQL Server中，你在Concat之前做“前1”。

此外，根据您的表格的布局，您还需要在“concat”之前添加“distinct”（没有括号或逗号），以删除重复项。

Answer 2

尝试使用SUM，GROUP BY和ORDER BY ...这样做可以吗？

SELECT CONCAT(customer.First_Name, ‘’, customer.Last_Name), 
       Phone_Numbers.Number, 
       Customer.ID,
       SUM(Sales_Detail.Price) AS Total_Purchases
FROM Sales_Header 
INNER JOIN Sales_Detail ON Sales_Detail.Header_ID = Sales_Header.ID 
INNER JOIN Customer ON Customer.ID = Sales_Header.Customer_ID 
INNER JOIN Phone_Numbers ON Phone_Numbers.Customer_ID = Customer.ID 
WHERE Sales_Header.WebSale = -1 
  AND Sales_Detail.Price > 1000 
  AND DateSold > 20081002
GROUP BY Customer.ID
ORDER BY Total_Purchases

MySQL：找出客户花费最多的商店

2 个答案: