Question

我正试图在销售系统中获得出色的平衡。我通过组合3个表来实现这一点，因为它有多对多的关系。根据MSDN

“LEFT JOIN或RIGHT JOIN可以嵌套在INNER JOIN中，但是 INNER JOIN不能嵌套在LEFT JOIN或RIGHT JOIN“
中

但是当我运行查询时，我收到错误"JOIN expression not supported" 这是我的代码：

SELECT DISTINCTROW Table1.CustomerName, Sum(Table1.TotalAmount) AS [Total Payable Amount]
, Sum(Table2.PaidAmount) AS [Total Paid Amount]
, Sum(Table1.TotalAmount - Table2.PaidAmount) AS [Total Outstanding Balance]

FROM Table2 

INNER JOIN 
(Table1 LEFT JOIN Table3 ON Table1.InvoiceNumber =Table3.InvoiceNumber) 
ON Table2.ReceiptNumber = Table3.ReceiptNumber

GROUP BY Table1.CustomerName;

Answer 1

一种选择是将LEFT JOIN替换为INNER JOIN，并修改ON条件以保留Table1中不匹配的行，从而模拟LEFT JOIN }：

SELECT DISTINCTROW Table1.CustomerName, Sum(Table1.TotalAmount) AS [Total Payable Amount],
    Sum(Table2.PaidAmount) AS [Total Paid Amount]
    Sum(Table1.TotalAmount - Table2.PaidAmount) AS [Total Outstanding Balance]
FROM Table2 
INNER JOIN 
(
    SELECT Table1.*. Table3.ReceiptNumber
    FROM Table1 INNER JOIN Table3
        ON Table1.InvoiceNumber = Table3.InvoiceNumber
    UNION
    SELECT Table1.*, NULL
    FROM Table1
    WHERE Table1.InvoiceNumber NOT IN (SELECT Table3.InvoiceNumber FROM Table3)
 )
ON Table2.ReceiptNumber = Table3.ReceiptNumber
GROUP BY Table1.CustomerName;

Answer 2

我总是在使用MS Access SQL。但是在桌面设计师的帮助下，我认为我发现了你的语法错误。尝试将FROM子句更改为：

FROM 
    (
        Table2 INNER JOIN Table3 ON Table2.ReceiptNumber = Table3.ReceiptNumber
    ) 
LEFT JOIN Table1 ON Table3.InvoiceNumber = Table1.InvoiceNumber;

这里的关键是重构您的查询，以便INNER连接出现在括号内，LEFT连接出现在外面。

使用LEFT JOIN时，MS Access 2016“不支持JOIN表达式”

2 个答案: