[SQL] 累積

http://sql55.com/query/cumulative-amount-1.php

SELECT S1.SalesDate,

        S1.SalesAmount,
        SUM(S2.SalesAmount) AS CumulativeAmount

FROM Sales1 AS S1

           INNER JOIN Sales1 AS S2
              ON S1.SalesDate >= S2.SalesDate

GROUP BY S1.SalesDate, S1.SalesAmount
ORDER BY S1.SalesDate;