Question

我在MS Access中工作，需要一个SQL解决方案。我有三张桌子：

客户： CustNum （密钥），名称
订单： ID ， CustNum ，金额
付款： ID ， CustNum ，值

我的问题是编写一个将导致查询的SQL：

CustomerName，TotalOderValue，TotalAmountPaid，BalancePayable 。

我在 CustNum 分组的三个表上尝试了下面的Select查询，但是它起作用了，但似乎是由于重复行而使得汇总气球。

SELECT CustNum, 
       Sum(Amount) AS TotalOrderValue, 
       Sum(Value) AS TotalAmountPaid, 
       [TotalOrderValue]-[TotalAmoutPaid] AS BalancePayable  
FROM (Customers Inner Join Payments ON Customers.CustNum=Payments.CustNum) 
INNER JOIN Orders ON Customers.CustNum=Orders.CustNum GROUP BY Customers.CustNum

Answer 1

基本访问功能。

构建2个聚合查询。然后构建另一个将其连接到Customers表的查询。

如果需要，也可以在第三个查询中嵌套2个聚合查询。使用SQL View将2个聚合查询复制/粘贴到第三个查询中，然后可以删除2个聚合查询对象。这是一体化查询：

SELECT Customers.CustNum, Query1.TotalAmountPaid, Query2.TotalOrderValue, [TotalAmountPaid]-[TotalOrderValue] AS BalancePayable
FROM 
(SELECT Payments.CustNum, Sum(Payments.Value) AS TotalOrderValue FROM Payments GROUP BY Payments.CustNum) AS Query2 
RIGHT JOIN (
(SELECT Orders.CustNum, Sum(Orders.Amount) AS TotalAmountPaid FROM Orders GROUP BY Orders.CustNum) AS Query1 
RIGHT JOIN Customers ON Query1.CustNum = Customers.CustNum) ON Query2.CustNum = Customers.CustNum;

使用group by获取三个表的sql

1 个答案: