在T-SQL中，如何根据第二列的条件获取行的值？

Question

我有一个看起来像这样的表：

InvoiceNumber   AccountNumber   SumAmount
---------------------------------------------
1765            4150            20687.5000
1765            1100            20687.5000
1766            4150            41895.0000
1766            7730               20.0000
1797            4150                0.0000
1797            7730               20.0000
1797            1100             6652.3400
1797            4990             6652.3400

由此查询生成：

SELECT InvoiceNumber
    ,AccountNumber
    ,SUM(Amount) AS SumAmount
FROM vINVOICE_TABLE
GROUP BY InvoiceNumber
    ,AccountNumber
ORDER BY InvoiceNumber

我想应用这个逻辑：

• 如果SumAmount_Account 1 > SumAmount_Account2，请Account1
• 如果SumAmount_Account 1 == SumAmount_Account2，请使用编号较高的帐户

所以，结果应如下所示：

InvoiceNumber   AccountNumber
---------------------------------
1765            4150
1766            4150
1797            4990

Answer 1

这可以做到。

SELECT InvoiceNumber, AccountNumber
FROM 
(
    SELECT  
        Row_Number() OVER(
            Partition BY InvoiceNumber  
            ORDER BY SUM(Amount) DESC, AccountNumber DESC
        ) rowNumber,
        InvoiceNumber,
        AccountNumber
    FROM vINVOICE_TABLE
    GROUP BY InvoiceNumber, AccountNumber 
)inv
WHERE rowNumber = 1