我试图在EF中调用SQL标量函数。我试过不同的例子,但我不断得到:
类型y上的指定方法x不能转换为LINQ实体存储表达式。
我用的是.
查询:
注意我在选择中调用它..。
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()
// Contact portion
join measureTech in UnitOfWork.User on rtuDevice.MeasurementTechnicianId equals measureTech.Id into measureTechLEFTJOIN
from measureTech in measureTechLEFTJOIN.DefaultIfEmpty()
join commTech in UnitOfWork.User on rtuDevice.CommunicationTechnicianId equals commTech.Id into commTechLEFTJOIN
from commTech in commTechLEFTJOIN.DefaultIfEmpty()
// Connection portion
join deviceCircuit in UnitOfWork.DeviceCircuit on device.Id equals deviceCircuit.DeviceId into deviceCircuitLEFTJOIN
from deviceCircuit in deviceCircuitLEFTJOIN.DefaultIfEmpty()
join circuit in UnitOfWork.Circuit on deviceCircuit.CircuitId equals circuit.Id
join circuitConnection in UnitOfWork.CircuitConnection on circuit.Id equals circuitConnection.CircuitId
join connection in UnitOfWork.Connection on circuitConnection.ConnectionId equals connection.Id
where
deviceCircuit.IsPrimary == true
select new MeterDataItem()
{
MeterId = meter.Id,
MeterNumber = meter.MeterNumber,
MeterName = meter.MeterName,
MeterTypeId = meterType.Id,
MeterTypeName = meterType.MeterTypeName,
MeterPositionCategory = meterPosition.EFMMeterPositionCategory,
FlowTypeName = flowType.FlowTypeName,
FluidTypeCategory = fluidType.FluidTypeCategory,
RunStatusCategory = runStatus.RunStatusCategory,
PipelineName = pipeline.PipelineName,
CompanyName = company.CompanyName,
ConnectionValue = GetConnection(circuitConnection.Id, connection.ConnectionTypeName),
DeviceId = device.Id,
DeviceName = device.DeviceName,
MeasurementTechnicianId = measureTech.Id,
MeasurementTechnicianFirstName = measureTech.FirstName,
MeasurementTechnicianLastName = measureTech.LastName,
CommunicationTechnicianId = commTech.Id,
CommunicationTechnicianFirstName = commTech.FirstName,
CommunicationTechnicianLastName = commTech.LastName,
MeterObjectStateName = null, //<-- Default Value
FavoriteId = 0 //<-- Default Value
};
return query.OrderBy(x => x.MeterNumber);
}CSHARP-函数:
我猜因为某种原因它找不到功能..。
[Function(FunctionType.ComposableScalarValuedFunction, nameof(svfn_GetMeterConnection), Schema = "dbo")]
[return: Parameter(DbType = "VARCHAR(100)")]
public string svfn_GetMeterConnection([Parameter(DbType = "INT")]int circuitConnectionId, [Parameter(DbType = "VARCHAR(50)")]string connectionTypeName)
{
ObjectParameter circuitConnectionIdParameter = new ObjectParameter("@CircuitConnectionId", circuitConnectionId);
ObjectParameter connectionTypeNameParameter = new ObjectParameter("@ConnectionTypeName", connectionTypeName);
return UnitOfWork.DbContext.ObjectContext().ExecuteFunction<string>(nameof(this.svfn_GetMeterConnection), circuitConnectionIdParameter, connectionTypeNameParameter).SingleOrDefault();
}SQL-函数:
我所有的名字和参数名引用看起来都是对的..。
ALTER FUNCTION [dbo].[svfn_GetMeterConnection]
(
@CircuitConnectionId INT,
@ConnectionTypeName VARCHAR(50)
)
RETURNS VARCHAR(100)
AS
BEGIN
DECLARE @Value VARCHAR(100) = NULL;
-- DIAL-UP
IF(@ConnectionTypeName = 'Dial-Up')
BEGIN
SELECT
@Value = circuitConnectionConfiguration.ConnectionPropertyValue
FROM [dbo].[CircuitConnectionConfiguration] circuitConnectionConfiguration
JOIN [dbo].[ConnectionConfiguration] connectionConfiguration ON connectionConfiguration.Id = circuitConnectionConfiguration.ConnectionConfigurationId
JOIN [dbo].[ConnectionProperty] connProperty ON connProperty.Id = connectionConfiguration.ConnectionPropertyId
WHERE
circuitConnectionConfiguration.CircuitConnectionId = @CircuitConnectionId
AND connProperty.ConnectionPropertyName = 'Dial-Up Number'
END
-- INTERNET PROTOCOL (IP)
IF(@ConnectionTypeName = 'Internet Protocol (IP)')
BEGIN
SELECT @Value =
((SELECT circuitConnectionConfiguration.ConnectionPropertyValue
FROM [dbo].[CircuitConnectionConfiguration] circuitConnectionConfiguration
JOIN [dbo].[ConnectionConfiguration] connectionConfiguration ON connectionConfiguration.Id = circuitConnectionConfiguration.ConnectionConfigurationId
JOIN [dbo].[ConnectionProperty] connProperty ON connProperty.Id = connectionConfiguration.ConnectionPropertyId
WHERE
circuitConnectionConfiguration.CircuitConnectionId = @CircuitConnectionId
AND connProperty.ConnectionPropertyName = 'IP Address')
+ ':' +
(SELECT circuitConnectionConfiguration.ConnectionPropertyValue
FROM [dbo].[CircuitConnectionConfiguration] circuitConnectionConfiguration
JOIN [dbo].[ConnectionConfiguration] connectionConfiguration ON connectionConfiguration.Id = circuitConnectionConfiguration.ConnectionConfigurationId
JOIN [dbo].[ConnectionProperty] connProperty ON connProperty.Id = connectionConfiguration.ConnectionPropertyId
WHERE
circuitConnectionConfiguration.CircuitConnectionId = @CircuitConnectionId
AND connProperty.ConnectionPropertyName = 'Port'))
END
-- Return the result of the function
RETURN @Value
END更新-回答:
我需要的一些更改包括:
混凝土DBCONTEXT:
包括名字空间..。
using EntityFramework.Functions;
using StructureMap;
using System.Configuration;
using System.Data.Entity;
using System.Data.Entity.Core.Objects;
using System.Linq;
public class MeasurementContractsDbContext : BaseDbContext
{
#region <Constructors>
[DefaultConstructor]
public MeasurementContractsDbContext() : base(Settings.ConnectionString.Database.MeasurementContractsDb)
{
Database.SetInitializer<MeasurementContractsDbContext>(null);
Database.CommandTimeout = int.Parse(ConfigurationManager.AppSettings[Settings.Command.TimeoutInterval]);
Configuration.ProxyCreationEnabled = false;
}
#endregion
#region <Methods>
[Function(FunctionType.ComposableScalarValuedFunction, nameof(svfn_GetMeterConnection), Schema = "dbo")]
[return: Parameter(DbType = "varchar")]
public string svfn_GetMeterConnection(int circuitConnectionId, string connectionTypeName)
{
ObjectParameter circuitConnectionIdParameter = new ObjectParameter("CircuitConnectionId", circuitConnectionId);
ObjectParameter connectionTypeNameParameter = new ObjectParameter("ConnectionTypeName", connectionTypeName);
return this.ObjectContext().ExecuteFunction<string>(nameof(this.svfn_GetMeterConnection), circuitConnectionIdParameter, connectionTypeNameParameter).SingleOrDefault();
}
[Function(FunctionType.ComposableScalarValuedFunction, nameof(svfn_GetCurrentObjectStateName), Schema = "dbo")]
[return: Parameter(DbType = "varchar")]
public string svfn_GetCurrentObjectStateName(int contextId, string contextFullName)
{
ObjectParameter contextIdParameter = new ObjectParameter("contextId", contextId);
ObjectParameter contextFullNameParameter = new ObjectParameter("contextFullName", contextFullName);
return this.ObjectContext().ExecuteFunction<string>(nameof(this.svfn_GetCurrentObjectStateName), contextIdParameter, contextFullNameParameter).SingleOrDefault();
}
protected override void OnModelCreating(DbModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
// ADD Functions
modelBuilder.Conventions.Add(new FunctionConvention<MeasurementContractsDbContext>());
// ...
}
#endregion
}示例用法:
/// <exception cref="ArgumentNullException">Non-Existent 'Query' value throws this exception</exception>
public IQueryable<MeterDetailDataItem> AuthorizationToFlowMeterDocumentFilter(IQueryable<MeterDetailDataItem> query)
{
if (query == null)
throw new ArgumentNullException("Query");
string contextFullName = typeof(AuthorizationToFlowMeterDocument).FullName;
// Get the ATF (if it exists)
var filteredQuery = (from dataitem in query //<-- QUERY
join document in UnitOfWork.Document on dataitem.RequestToFlowMeterDocumentId equals document.ParentId
// TODO: Figure out if you can move svfn_GetCurrentObjectStateName into an Algorythm class that can be injected
// SQL Function
let objectStateName = ((MeasurementContractsDbContext)UnitOfWork.DbContext).svfn_GetCurrentObjectStateName(document.Id, contextFullName)
select new MeterDetailDataItem()
{
MeterId = dataitem.MeterId,
RequestToFlowMeterDocumentId = dataitem.RequestToFlowMeterDocumentId,
RequestToFlowMeterDocumentObjectStateName = dataitem.RequestToFlowMeterDocumentObjectStateName,
AuthorizationToFlowMeterDocumentId = document.Id,
AuthorizationToFlowMeterDocumentObjectStateName = objectStateName,
FirstDeliveryNoticeDocumentId = dataitem.FirstDeliveryNoticeDocumentId,
FirstDeliveryNoticeDocumentObjectStateName = dataitem.FirstDeliveryNoticeDocumentObjectStateName,
FavoriteId = dataitem.FavoriteId
});
return filteredQuery.OrderBy(x => x.MeterId);
}发布于 2018-05-30 08:19:36
看起来您正在使用EntityFramework.Functions包。然后看一看函数主题。您使用的是标量值函数,即不可组合的,根据包作者
可以像其他上述方法一样直接调用。
但
但是,由于它被指定为不可组合的,所以它不能通过LINQ查询中的实体框架进行转换。
和
这是实体框架的设计
虽然您需要的是标量值函数,可组合的,它
在LINQ实体查询中工作,但不能直接调用。
很短的时间内,由于您在LINQ中使用它,所以在FunctionType.ComposableScalarValuedFunction内使用Function注释。由于它不是直接调用的,所以它不需要方法主体,所以您可以简单地抛出异常:
[Function(FunctionType.ComposableScalarValuedFunction, nameof(svfn_GetMeterConnection), Schema = "dbo")]
public string svfn_GetMeterConnection(int circuitConnectionId, string connectionTypeName)
{
throw new NotSupportedException();
}不要忘记如链接中所示注册函数,否则它们将不会生效,您将继续获得NotSupportedException
modelBuilder.Conventions.Add(new FunctionConvention<TheClassContainingTheFunction>());https://stackoverflow.com/questions/50591873
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