“列名无效”的解决方法

Question

您好，这个有什么解决方法吗？

SELECT        invoices.no, customers.name, invoices.mdcode,
SUM(iproducts.unitprice * iproducts.quantity) AS total,
SUM(iproducts.unitprice * iproducts.quantity) - SUM(rinvoices.payment + rinvoices.discount)
AS [Remaining Balance]
FROM          invoices INNER JOIN
              customers ON customers.id = invoices.customerid INNER JOIN
              iproducts ON invoices.id = iproducts.invoiceid LEFT OUTER JOIN
              rinvoices ON invoices.id = rinvoices.invoiceid
WHERE        ([Remaining Balance] <> '0')
GROUP BY invoices.no, customers.name, invoices.mdcode

以下返回一个错误，即“[剩余余额]”不是一个有效的列，而我已经声明了它。我不能在 WHERE 和 CASE 子句中使用它。是否有任何解决方法，因为我真的只需要获取仍有余额的发票。

感谢您的帮助！

Answer 1

你必须像这样使用 HAVING 子句

HAVING SUM(rinvoices.payment) - SUM(rinvoices.discount) <> 0

而不是在哪里

即：

SELECT        invoices.no, customers.name, invoices.mdcode,
SUM(iproducts.unitprice * iproducts.quantity) AS total,
SUM(iproducts.unitprice * iproducts.quantity) - SUM(rinvoices.payment + rinvoices.discount)
AS [Remaining Balance]
FROM          invoices INNER JOIN
              customers ON customers.id = invoices.customerid INNER JOIN
              iproducts ON invoices.id = iproducts.invoiceid LEFT OUTER JOIN
              rinvoices ON invoices.id = rinvoices.invoiceid
GROUP BY invoices.no, customers.name, invoices.mdcode
HAVING SUM(rinvoices.payment) - SUM(rinvoices.discount) <> 0