在没有 EDMX 的 LINQ 语句中调用标量函数

Question

我正在尝试在 EF 中调用 SQL SCALAR 函数。我尝试了各种示例，但我不断收到：

无法将类型 y 上的指定方法 x 转换为 LINQ to Entities 存储表达式。

我在用...

• 英孚 6.1.3

• EntityFramework.Functions 1.4.1

查询：
注意我在 SELECT 中调用它...

public IQueryable<MeterDataItem> Query()

{

    var query = from meter in UnitOfWork.Meter

                join meterType in UnitOfWork.MeterType on meter.MeterTypeId equals meterType.Id into meterTypeLEFTJOIN

                    from meterType in meterTypeLEFTJOIN.DefaultIfEmpty()

                join company in UnitOfWork.Company on meter.CompanyId equals company.Id

                join meterPosition in UnitOfWork.EFMMeterPosition on meter.EFMMeterPositionId equals meterPosition.Id into meterPositionLEFTJOIN

                    from meterPosition in meterPositionLEFTJOIN.DefaultIfEmpty()

                join flowType in UnitOfWork.FlowType on meter.FlowTypeId equals flowType.Id into flowTypeLEFTJOIN

                    from flowType in flowTypeLEFTJOIN.DefaultIfEmpty()

                join fluidType in UnitOfWork.FluidType on meter.FluidTypeId equals fluidType.Id into fluidTypeLEFTJOIN

                    from fluidType in fluidTypeLEFTJOIN.DefaultIfEmpty()

                join runStatus in UnitOfWork.RunStatus on meter.RunStatusId equals runStatus.Id into runStatusLEFTJOIN

                    from runStatus in runStatusLEFTJOIN.DefaultIfEmpty()

                join pipeline in UnitOfWork.Pipeline on meter.PipelineId equals pipeline.Id into pipelineLEFTJOIN

                    from pipeline in pipelineLEFTJOIN.DefaultIfEmpty()

                // Device portion

                join device in UnitOfWork.Device on meter.DeviceId equals device.Id into deviceLEFTJOIN

                    from device in deviceLEFTJOIN.DefaultIfEmpty()

                join rtuDevice in UnitOfWork.RTUDevice on device.Id equals rtuDevice.DeviceId into rtuDeviceLEFTJOIN

                    from rtuDevice in rtuDeviceLEFTJOIN.DefaultIfEmpty()