MySQL-基于同一张表中的行求和的列值

我认为您正在使此过程变得比需要的复杂。

SELECt    ProductID,    SUM(IF(PaymentMethod = 'Cash', Amount, 0)) AS 'Cash',    -- snip    SUM(Amount) AS TotalFROM    PaymentsWHERe    SaleDate = '2012-02-10'GROUP BY    ProductID