sql - IIF Microsoft Access 语句错误帮助 - 一个查询中有多个 IIF 语句

Question

希望有人能帮助我。

我正在尝试运行此查询，但出现以下错误。我需要基于不同表中的不同字段构建逻辑，然后将该数据写入表中的新字段。这只是我查询的开始，但我已经收到错误：/

我试图写的逻辑是

如果 Containersize = '20' 且 CBMRate PLX < 20MRate 则使用 CBMRate PLX 否则使用 20MRate 如果 Containersize = '40' 且 CBMRate PLX < 40MRate 然后使用 CBMRate PLX 否则使用 40MRate 如果 Containersize = 'LCL' 且 CBMRate PLX < LCLMRate 则使用 CBMRate PLX 否则 LCLMRate

这是我写的查询，但我有一些语法错误。任何帮助，将不胜感激。:)

Select IIF ([Shipments]![ContainerSize] = '20') ,
(IIF (([CustomerRates]![CBMRate] * [Shipments]![PLX]) < [CustomerRates]![20MRate]) , ([CustomerRates]![CBMRate] * [Shipments]![PLX]) , ([CustomerRates]![20MRate])) , (IIF 
([Shipments]![ContainerSize] = '40') ,
(IIF ([CustomerRates]![CBMRate] * [Shipments]![PLX]) < [CustomerRates]![40MRate]), ([CustomerRates]![CBMRate] * [Shipments]![PLX]) , ([CustomerRates]![40MRate])),
(IIF  ([CustomerRates]![CBMRate] * [Shipments]![PLX]) < [CustomerRates]![LCLMRate]), ([CustomerRates]![CBMRate] * [Shipments]![PLX]) , ([CustomerRates]![LCLMRate]))
From [CustomerRates] , [Shipments]
Where
[shipments]![customerid]=[customerRates]![customerid]

Answer 1

考虑：

IIf([ContainerSize] = 20, IIf([CBMRate] * [PLX] < [20MRate], [CBMRate] * [PLX], [20MRate]), 
    IIf([ContainerSize] = 40, IIf([CBMRate] * [PLX] < [40MRate], [CBMRate] * [PLX], [40MRate]),
        IIf([CBMRate] * [PLX] < [LCLMRate]), [CBMRate] * [PLX], [LCLMRate])))

或者

Switch([ContainerSize] = 20, IIf([CBMRate] * [PLX] < [20MRate], [CBMRate] * [PLX], [20MRate]),
       [ContainerSize] = 40, IIf([CBMRate] * [PLX] < [40MRate], [CBMRate] * [PLX], [40MRate]),
       True, IIf([CBMRate] * [PLX] < [LCLMRate]), [CBMRate] * [PLX], [LCLMRate]))