1. 技术文章
  2. How to enable $expand and $select on ODataQueryOptions?

How to enable $expand and $select on ODataQueryOptions?

由 好久不见. 提交于 2019-12-22 05:15:27

问题


The issue started here, where I am unable to call $select or $expand on results.

Given: 

            var results = options.ApplyTo(_uow.Repository<ContentType>()
                .Query()
                .Get()
                .Include(u => u.User)
                .Where(u => u.UserId == userId)
                .OrderBy(o => o.Description)).Cast<ContentType>()
                .Select(x => new ContentTypeDTO()
                {
                    //projection goes here
                    ContentTypeId = x.ContentTypeId,
                    Description = x.Description,
                    UserDTO = new UserDTO 
                    { 
                        UserId = x.UserId,
                        UserName = x.User.UserName
                    }
                });

Exception:

Unable to cast the type 'System.Web.Http.OData.Query.Expressions.SelectExpandBinder+SelectSome`1[[Project.DAL.Data.Models.ContentType, Project.DAL.Data, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]' to type 'Project.DAL.Data.Models.ContentType'. LINQ to Entities only supports casting EDM primitive or enumeration types."

Based on this solution, I understand that when $select or $expand are applied to the result, it is no longer a ContentType, as is expected by the Cast<ContentType>(). That solution uses HierarchyNodeExpressionVisitor, which I am unable to locate.

I want to use 'options.ApplyTo()' as I want the filtering done on the db server, to ensure I don't get back an inflated data set with hundreds of thousands of rows.

Is there a suggested way of getting around this?

-- UPDATE --

In using @Schandlich 's suggested solution below, the operation still fails with the Ok override:

Locals:

+       this    {Project.AdminWebsite.Api.Controllers.ContentTypeController}    Project.AdminWebsite.Api.Controllers.ODataBaseController {Project.AdminWebsite.Api.Controllers.ContentTypeController}
+       content {System.Data.Entity.Infrastructure.DbQuery<Project.Core.UI.Models.ContentTypeDTO>}  object {System.Data.Entity.Infrastructure.DbQuery<Project.Core.UI.Models.ContentTypeDTO>}
+       type    {Name = "DbQuery`1" FullName = "System.Data.Entity.Infrastructure.DbQuery`1[[Project.Core.UI.Models.ContentTypeDTO, Project.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]"} System.Type {System.RuntimeType}
+       resultType  {Name = "OkNegotiatedContentResult`1" FullName = "System.Web.Http.Results.OkNegotiatedContentResult`1[[System.Data.Entity.Infrastructure.DbQuery`1[[Project.Core.UI.Models.ContentTypeDTO, Project.Core, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]], EntityFramework, Version=6.0.0.0, Culture=neutral, PublicKeyToken=b77a5c561934e089]]"}    System.Type {System.RuntimeType}
+       result  {System.Web.Http.Results.OkNegotiatedContentResult<System.Data.Entity.Infrastructure.DbQuery<Project.Core.UI.Models.ContentTypeDTO>>}   System.Web.Http.IHttpActionResult {System.Web.Http.Results.OkNegotiatedContentResult<System.Data.Entity.Infrastructure.DbQuery<Project.Core.UI.Models.ContentTypeDTO>>}

Call stack:

>   Project.AdminWebsite.dll!Project.AdminWebsite.Api.Controllers.ODataBaseController.Ok(object content, System.Type type) Line 27  C#
    Project.AdminWebsite.dll!Project.AdminWebsite.Api.Controllers.ContentTypeController.Get(System.Web.Http.OData.Query.ODataQueryOptions<Project.DAL.Data.Models.ContentType> odataQueryOptions) Line 132  C#
    [Lightweight Function]  
    System.Web.Http.dll!System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.GetExecutor.AnonymousMethod__9(object instance, object[] methodParameters) Unknown
    System.Web.Http.dll!System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(object instance, object[] arguments)   Unknown
    System.Web.Http.dll!System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ExecuteAsync(System.Web.Http.Controllers.HttpControllerContext controllerContext, System.Collections.Generic.IDictionary<string,object> arguments, System.Threading.CancellationToken cancellationToken)  Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.Tracers.HttpActionDescriptorTracer.ExecuteAsync.AnonymousMethod__1()    Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.ITraceWriterExtensions.TraceBeginEndAsync<object>(System.Web.Http.Tracing.ITraceWriter traceWriter, System.Net.Http.HttpRequestMessage request, string category, System.Web.Http.Tracing.TraceLevel level, string operatorName, string operationName, System.Action<System.Web.Http.Tracing.TraceRecord> beginTrace, System.Func<System.Threading.Tasks.Task<object>> execute, System.Action<System.Web.Http.Tracing.TraceRecord,object> endTrace, System.Action<System.Web.Http.Tracing.TraceRecord> errorTrace)   Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.Tracers.HttpActionDescriptorTracer.ExecuteAsync(System.Web.Http.Controllers.HttpControllerContext controllerContext, System.Collections.Generic.IDictionary<string,object> arguments, System.Threading.CancellationToken cancellationToken) Unknown
    System.Web.Http.dll!System.Web.Http.Controllers.ApiControllerActionInvoker.InvokeActionAsyncCore()  Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start<System.Web.Http.Controllers.ApiControllerActionInvoker.InvokeActionAsyncCore>(ref System.Web.Http.Controllers.ApiControllerActionInvoker.InvokeActionAsyncCore stateMachine)  Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncTaskMethodBuilder<System.__Canon>.Start<System.Web.Http.Controllers.ApiControllerActionInvoker.InvokeActionAsyncCore>(ref System.Web.Http.Controllers.ApiControllerActionInvoker.InvokeActionAsyncCore stateMachine)  Unknown
    System.Web.Http.dll!System.Web.Http.Controllers.ApiControllerActionInvoker.InvokeActionAsyncCore(System.Web.Http.Controllers.HttpActionContext actionContext, System.Threading.CancellationToken cancellationToken) Unknown
    System.Web.Http.dll!System.Web.Http.Controllers.ApiControllerActionInvoker.InvokeActionAsync(System.Web.Http.Controllers.HttpActionContext actionContext, System.Threading.CancellationToken cancellationToken) Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.Tracers.HttpActionInvokerTracer.System.Web.Http.Controllers.IHttpActionInvoker.InvokeActionAsync.AnonymousMethod__1()   Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.ITraceWriterExtensions.TraceBeginEndAsync<System.Net.Http.HttpResponseMessage>(System.Web.Http.Tracing.ITraceWriter traceWriter, System.Net.Http.HttpRequestMessage request, string category, System.Web.Http.Tracing.TraceLevel level, string operatorName, string operationName, System.Action<System.Web.Http.Tracing.TraceRecord> beginTrace, System.Func<System.Threading.Tasks.Task<System.Net.Http.HttpResponseMessage>> execute, System.Action<System.Web.Http.Tracing.TraceRecord,System.Net.Http.HttpResponseMessage> endTrace, System.Action<System.Web.Http.Tracing.TraceRecord> errorTrace)    Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.Tracers.HttpActionInvokerTracer.System.Web.Http.Controllers.IHttpActionInvoker.InvokeActionAsync(System.Web.Http.Controllers.HttpActionContext actionContext, System.Threading.CancellationToken cancellationToken) Unknown
    System.Web.Http.dll!System.Web.Http.Controllers.ActionFilterResult.ActionInvoker.InvokeActionAsync()    Unknown
    System.Web.Http.dll!System.Web.Http.Controllers.ActionFilterResult.ExecuteAsync()   Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start<System.Web.Http.Controllers.ActionFilterResult.ExecuteAsync>(ref System.Web.Http.Controllers.ActionFilterResult.ExecuteAsync stateMachine)    Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncTaskMethodBuilder<System.__Canon>.Start<System.Web.Http.Controllers.ActionFilterResult.ExecuteAsync>(ref System.Web.Http.Controllers.ActionFilterResult.ExecuteAsync stateMachine)    Unknown
    System.Web.Http.dll!System.Web.Http.Controllers.ActionFilterResult.ExecuteAsync(System.Threading.CancellationToken cancellationToken)   Unknown
    System.Web.Http.dll!System.Web.Http.ApiController.ExecuteAsync(System.Web.Http.Controllers.HttpControllerContext controllerContext, System.Threading.CancellationToken cancellationToken)   Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.Tracers.HttpControllerTracer.ExecuteAsyncCore() Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start<System.Web.Http.Tracing.Tracers.HttpControllerTracer.ExecuteAsyncCore>(ref System.Web.Http.Tracing.Tracers.HttpControllerTracer.ExecuteAsyncCore stateMachine)    Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncTaskMethodBuilder<System.__Canon>.Start<System.Web.Http.Tracing.Tracers.HttpControllerTracer.ExecuteAsyncCore>(ref System.Web.Http.Tracing.Tracers.HttpControllerTracer.ExecuteAsyncCore stateMachine)    Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.Tracers.HttpControllerTracer.ExecuteAsyncCore(System.Web.Http.Controllers.HttpControllerContext controllerContext, System.Threading.CancellationToken cancellationToken)    Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.Tracers.HttpControllerTracer.System.Web.Http.Controllers.IHttpController.ExecuteAsync.AnonymousMethod__0()  Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.ITraceWriterExtensions.TraceBeginEndAsync<System.Net.Http.HttpResponseMessage>(System.Web.Http.Tracing.ITraceWriter traceWriter, System.Net.Http.HttpRequestMessage request, string category, System.Web.Http.Tracing.TraceLevel level, string operatorName, string operationName, System.Action<System.Web.Http.Tracing.TraceRecord> beginTrace, System.Func<System.Threading.Tasks.Task<System.Net.Http.HttpResponseMessage>> execute, System.Action<System.Web.Http.Tracing.TraceRecord,System.Net.Http.HttpResponseMessage> endTrace, System.Action<System.Web.Http.Tracing.TraceRecord> errorTrace)    Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.Tracers.HttpControllerTracer.System.Web.Http.Controllers.IHttpController.ExecuteAsync(System.Web.Http.Controllers.HttpControllerContext controllerContext, System.Threading.CancellationToken cancellationToken)    Unknown
    System.Web.Http.dll!System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsyncCore(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken) Unknown
    System.Web.Http.dll!System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsync() Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start<System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsync>(ref System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsync stateMachine)    Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncTaskMethodBuilder<System.__Canon>.Start<System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsync>(ref System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsync stateMachine)    Unknown
    System.Web.Http.dll!System.Web.Http.Dispatcher.HttpControllerDispatcher.SendAsync(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken) Unknown
    System.Net.Http.dll!System.Net.Http.HttpMessageInvoker.SendAsync(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)  Unknown
    System.Web.Http.dll!System.Web.Http.Dispatcher.HttpRoutingDispatcher.SendAsync(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)    Unknown
    System.Net.Http.dll!System.Net.Http.DelegatingHandler.SendAsync(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)   Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.Tracers.RequestMessageHandlerTracer.AnonymousMethod__FabricatedMethod6()    Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.Tracers.RequestMessageHandlerTracer.SendAsync.AnonymousMethod__1()  Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.ITraceWriterExtensions.TraceBeginEndAsync<System.Net.Http.HttpResponseMessage>(System.Web.Http.Tracing.ITraceWriter traceWriter, System.Net.Http.HttpRequestMessage request, string category, System.Web.Http.Tracing.TraceLevel level, string operatorName, string operationName, System.Action<System.Web.Http.Tracing.TraceRecord> beginTrace, System.Func<System.Threading.Tasks.Task<System.Net.Http.HttpResponseMessage>> execute, System.Action<System.Web.Http.Tracing.TraceRecord,System.Net.Http.HttpResponseMessage> endTrace, System.Action<System.Web.Http.Tracing.TraceRecord> errorTrace)    Unknown
    System.Web.Http.dll!System.Web.Http.Tracing.Tracers.RequestMessageHandlerTracer.SendAsync(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken) Unknown
    System.Net.Http.dll!System.Net.Http.DelegatingHandler.SendAsync(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)   Unknown
    System.Web.Http.dll!System.Web.Http.HttpServer.AnonymousMethod__FabricatedMethod9() Unknown
    System.Web.Http.dll!System.Web.Http.HttpServer.SendAsync()  Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start<System.Web.Http.HttpServer.SendAsync>(ref System.Web.Http.HttpServer.SendAsync stateMachine)  Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncTaskMethodBuilder<System.__Canon>.Start<System.Web.Http.HttpServer.SendAsync>(ref System.Web.Http.HttpServer.SendAsync stateMachine)  Unknown
    System.Web.Http.dll!System.Web.Http.HttpServer.SendAsync(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)  Unknown
    System.Net.Http.dll!System.Net.Http.HttpMessageInvoker.SendAsync(System.Net.Http.HttpRequestMessage request, System.Threading.CancellationToken cancellationToken)  Unknown
    System.Web.Http.WebHost.dll!System.Web.Http.WebHost.HttpControllerHandler.ProcessRequestAsyncCore() Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncMethodBuilderCore.Start<System.Web.Http.WebHost.HttpControllerHandler.ProcessRequestAsyncCore>(ref System.Web.Http.WebHost.HttpControllerHandler.ProcessRequestAsyncCore stateMachine)    Unknown
    mscorlib.dll!System.Runtime.CompilerServices.AsyncTaskMethodBuilder.Start<System.Web.Http.WebHost.HttpControllerHandler.ProcessRequestAsyncCore>(ref System.Web.Http.WebHost.HttpControllerHandler.ProcessRequestAsyncCore stateMachine)    Unknown
    System.Web.Http.WebHost.dll!System.Web.Http.WebHost.HttpControllerHandler.ProcessRequestAsyncCore(System.Web.HttpContextBase contextBase)   Unknown
    System.Web.Http.WebHost.dll!System.Web.Http.WebHost.HttpControllerHandler.ProcessRequestAsync(System.Web.HttpContext context)   Unknown
    System.Web.dll!System.Web.HttpTaskAsyncHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest.AnonymousMethod__0()    Unknown
    System.Web.dll!System.Web.TaskAsyncHelper.BeginTask(System.Func<System.Threading.Tasks.Task> taskFunc, System.AsyncCallback callback, object state) Unknown
    System.Web.dll!System.Web.HttpTaskAsyncHandler.System.Web.IHttpAsyncHandler.BeginProcessRequest(System.Web.HttpContext context, System.AsyncCallback cb, object extraData)  Unknown
    System.Web.dll!System.Web.HttpApplication.CallHandlerExecutionStep.System.Web.HttpApplication.IExecutionStep.Execute()  Unknown
    System.Web.dll!System.Web.HttpApplication.ExecuteStep(System.Web.HttpApplication.IExecutionStep step, ref bool completedSynchronously)  Unknown
    System.Web.dll!System.Web.HttpApplication.PipelineStepManager.ResumeSteps(System.Exception error)   Unknown
    System.Web.dll!System.Web.HttpApplication.BeginProcessRequestNotification(System.Web.HttpContext context, System.AsyncCallback cb)  Unknown
    System.Web.dll!System.Web.HttpRuntime.ProcessRequestNotificationPrivate(System.Web.Hosting.IIS7WorkerRequest wr, System.Web.HttpContext context)    Unknown
    System.Web.dll!System.Web.Hosting.PipelineRuntime.ProcessRequestNotificationHelper(System.IntPtr rootedObjectsPointer, System.IntPtr nativeRequestContext, System.IntPtr moduleData, int flags) Unknown
    System.Web.dll!System.Web.Hosting.PipelineRuntime.ProcessRequestNotification(System.IntPtr rootedObjectsPointer, System.IntPtr nativeRequestContext, System.IntPtr moduleData, int flags)   Unknown
    [Native to Managed Transition]  
    [Managed to Native Transition]  
    System.Web.dll!System.Web.Hosting.PipelineRuntime.ProcessRequestNotificationHelper(System.IntPtr rootedObjectsPointer, System.IntPtr nativeRequestContext, System.IntPtr moduleData, int flags) Unknown
    System.Web.dll!System.Web.Hosting.PipelineRuntime.ProcessRequestNotification(System.IntPtr rootedObjectsPointer, System.IntPtr nativeRequestContext, System.IntPtr moduleData, int flags)   Unknown
    [AppDomain Transition]

Error Message:

Unable to cast the type 'System.Web.Http.OData.Query.Expressions.SelectExpandBinder+SelectAll`1[[Project.DAL.Data.Models.ContentType, Project.DAL.Data, Version=1.0.0.0, Culture=neutral, PublicKeyToken=null]]' to type 'Project.DAL.Data.Models.ContentType'. LINQ to Entities only supports casting EDM primitive or enumeration types.

回答1:


From $select and $expand break ODataQueryOptions -- how to fix?

public IHttpActionResult Get(ODataQueryOptions<YourEntity> odataQueryOptions)
{
    //Your applyTo logic and results.

    if (odataQueryOptions.SelectExpand != null)
    {
        Request.SetSelectExpandClause(odataQueryOptions.SelectExpand.SelectExpandClause);
    }

    return Ok(results, results.GetType());
}

private IHttpActionResult Ok(object content, Type type)
{
    Type resultType = typeof(OkNegotiatedContentResult<>).MakeGenericType(type);
    return Activator.CreateInstance(resultType, content, this) as IHttpActionResult;
}

But as I stated in your other question, keep looking for ways to avoid manually applying the results if you can.



来源：https://stackoverflow.com/questions/21688857/how-to-enable-expand-and-select-on-odataqueryoptions

标签
c#
linq
odata
易学教程内所有资源均来自网络或用户发布的内容，如有违反法律规定的内容欢迎反馈！
该文章没有解决你所遇到的问题?点击提问,说说你的问题,让更多的人一起探讨吧!