我的计算产生了所需结果的一半。我有什么想法我做错了吗？

Question

我有两个表，一个叫做CarTypes，另一个叫做Hourly Rates。

CarType具有以下属性：

Id,
CarTypes,
Rates
HourlyID related to HourlyRates based on HourlyId-ID relationship.
Id is an AutoNumber
CarTypes are Sedan, 
Sports Utility, 
Stretch Limo 6 Passengers, 
Stretch Limo 8 passengers
Stretch Limo 10 Passengers
Stretch Limo 12 Passengers

每种车型都有自己的价格。

然后表HourlyRates具有以下属性： ID autoNumber， 每小时（最小时数为3）最大值为13及以上

我们的任务是将每个购物车类型的指定票价乘以用户选择的小时数，确定10％的折扣金额，确定（7％税）的税额，确定（20％）的小费或小费金额。 最后，那么，从票价中减去折扣，增加税额，添加提示金额以产生总金额。

到目前为止，我的计算仅显示轿车类型，轿车和运动型多功能车的所有价值（票价，折扣，小费，总数）。

有人可以告诉我我做错了吗？

提前致谢：

SELECT DISTINCT c.carTypes, h.hourly, h.hourly * IIf([CarTypes] = 'Sedan', 55, 
           IIf([CarTypes] = 'Stretch Limo : 6 Passenger)', 75,
           IIf([CarTypes] = 'Stretch Limo : 8 Passenger)', 90,
           IIf([CarTypes] = 'Stretch Limo : 10  Passenger)', 95,
           IIf([CarTypes] = 'Stretch Limo : 12  Passenger)', 110,
            IIf([CarTypes] = 'SportUtilityVehicle)', 110)))))) AS Fare, Fare*10/100 AS Discount, Fare-Discount AS NewFare, NewFare* 7/100 AS Tax, NewFare* 20/100 AS Tip, NewFare+Tax+TIP AS Total
FROM HourlyRates AS h INNER JOIN carType AS c ON h.ID= c.hourlyID;

Answer 1

除了Sedan之外，您在每个)的名称中都有额外的CarType，因此它们永远不会在嵌套的IIF()条件中捕获。

尝试：

SELECT DISTINCT c.carTypes, h.hourly, h.hourly * IIf([CarTypes] = 'Sedan', 55, 
           IIf([CarTypes] = 'Stretch Limo : 6 Passenger', 75,
           IIf([CarTypes] = 'Stretch Limo : 8 Passenger', 90,
           IIf([CarTypes] = 'Stretch Limo : 10  Passenger', 95,
           IIf([CarTypes] = 'Stretch Limo : 12  Passenger', 110,
            IIf([CarTypes] = 'SportUtilityVehicle', 110)))))) AS Fare, Fare*10/100 AS Discount, Fare-Discount AS NewFare, NewFare* 7/100 AS Tax, NewFare* 20/100 AS Tip, NewFare+Tax+TIP AS Total
FROM HourlyRates AS h INNER JOIN carType AS c ON h.ID= c.hourlyID;

我认为SWITCH()功能更容易理解：

SELECT DISTINCT c.carTypes, h.hourly, h.hourly * 
            SWITCH([CarTypes] = 'Sedan', 55
                  ,[CarTypes] = 'Stretch Limo : 6 Passenger', 75
                  ,[CarTypes] = 'Stretch Limo : 8 Passenger', 90
                  ,[CarTypes] = 'Stretch Limo : 10  Passenger', 95
                  ,[CarTypes] = 'Stretch Limo : 12  Passenger', 110
                  ,[CarTypes] = 'SportUtilityVehicle', 110
                  )  AS Fare
            , Fare*10/100 AS Discount
            , Fare-Discount AS NewFare
            , NewFare* 7/100 AS Tax
            , NewFare* 20/100 AS Tip
            , NewFare+Tax+TIP AS Total
FROM HourlyRates AS h INNER JOIN carType AS c ON h.ID= c.hourlyID;