查询运行减法

Question

我正在做一个项目，我需要计算所有到期的支付。我在查询中做了一个查询设计。但我无法查询总金额、已付金额、到期金额 amount 和 DueAmount 列值将从先前的 DueAmount 值中减去。这是查询：

SELECT Payment.PayDate, OrderMaster.OrderId, OrderMaster.CustomerName, OrderMaster.TotalAmount, Payment.PayAmount, OrderMaster.TotalAmount - Payment.PayAmount AS DueAmount FROM OrderMaster INNER JOIN Payment ON OrderMaster.OrderId = Payment.OrderId;

我得到这样的查询结果：

   PayDate   | OrderId  | CustomerName | TotalAmount | PayAmount | DueAmount
   -------------------------------------------------------------------------
   20/12/2014 |     1   | Someone      |   5000      |  2000      | 3000
   22/12/2014 |     1   | Someone      |   5000      |  1000      | 4000
   25/12/2014 |     1   | Someone      |   5000      |  2000      | 3000

我想要这样的查询结果：

    PayDate   | OrderId | CustomerName | TotalAmount | PayAmount | DueAmount
   -------------------------------------------------------------------------
   20/12/2014 |     1   | Someone      |   5000      |  2000      | 3000
   22/12/2014 |     1   | Someone      |   5000      |  1000      | 2000
   25/12/2014 |     1   | Someone      |   5000      |  2000      | 0

请帮助我进行准确的查询以获得此结果。谢谢

Answer 1

You may try like this:

select myField, myField -
(select myField from myTable where myOrderField =
(select max(myOrderField) from myTable where myOrderField < T.myOrderField))
as RunningDiff
from myTable as T

查询运行减法

Query Running Subtraction

sql

ms-access