如何有效地为特定列选择与最大值对应的行？

Question

我有一个查询：

SELECT * FROM `InvoiceLines`
INNER JOIN Invoices ON Invoices.`invoiceID` = InvoiceLines.`invoiceID`
INNER JOIN `DistributorOrdersTbl` ON DistributorOrdersTbl.`distOrderRecID` = Invoices.`orderID`
WHERE DistributorOrdersTbl.`distOrderRecID` = 3829
AND InvoiceLines.`qty` > 0

哪个会返回多个发票：

我只想选择ID为2800的最新发票。我最终的方式是复制粘贴：

SELECT * FROM `InvoiceLines`
INNER JOIN Invoices ON Invoices.`invoiceID` = InvoiceLines.`invoiceID`
INNER JOIN `DistributorOrdersTbl` ON DistributorOrdersTbl.`distOrderRecID` = Invoices.`orderID`
WHERE DistributorOrdersTbl.`distOrderRecID` = 3829
AND InvoiceLines.`qty` > 0
AND Invoices.invoiceID = (
        SELECT MAX(Invoices.invoiceID) FROM `InvoiceLines`
        INNER JOIN Invoices ON Invoices.`invoiceID` = InvoiceLines.`invoiceID`
        INNER JOIN `DistributorOrdersTbl` ON DistributorOrdersTbl.`distOrderRecID` = Invoices.`orderID`
        WHERE DistributorOrdersTbl.`distOrderRecID` = 3829
        AND InvoiceLines.`qty` > 0
    )

当然，可以返回正确的发票。但是，这似乎效率很低，因为我实际上执行了两次查询。最好的方法是什么？我尝试了以下操作，但看来这是不正确的SQL：

SELECT * FROM `InvoiceLines`
INNER JOIN Invoices ON Invoices.`invoiceID` = InvoiceLines.`invoiceID`
INNER JOIN `DistributorOrdersTbl` ON DistributorOrdersTbl.`distOrderRecID` = Invoices.`orderID`
WHERE DistributorOrdersTbl.`distOrderRecID` = 3829
AND InvoiceLines.`qty` > 0
AND Invoices.invoiceID = MAX(Invoices.invoiceID)

哪个返回“组功能的无效使用”。

谢谢！

Answer 1

假设所有发票都有发票行，则可以仅在Invoices上使用子查询：

SELECT *
FROM (SELECT i.*
      FROM Invoices i
      WHERE i.orderID = 3829
      ORDER BY i.invoiceID DESC
      LIMIT 1
     ) i JOIN
     InvoiceLines il
     ON i.invoiceID = il.invoiceID JOIN
     DistributorOrdersTbl d
     ON d.distOrderRecID = i.orderID
WHERE il.qty > 0;