Query Service PositionBasedPaging doesn't work in MVC WebAPI

Question

I want to get records by using paging from Query Service of Dynamics AX 2012 through MVC WebAPI. When I run this code in Console Application works fine.

QueryServiceClient client = new QueryServiceClient();

            DataSet dataSet;
            Paging paging = new PositionBasedPaging() { StartingPosition = 1, NumberOfRecordsToFetch = 10 };

            QueryMetadata query = new QueryMetadata();
            QueryDataSourceMetadata customerDataSource;

            query.QueryType = QueryType.Join;
            query.DataSources = new QueryDataSourceMetadata[1];

            customerDataSource = new QueryDataSourceMetadata();
            customerDataSource.Name = "AccountNum";
            customerDataSource.Enabled = true;
            customerDataSource.FetchMode = FetchMode.OneToOne;
            customerDataSource.Table = "CustTable";
            customerDataSource.Company = "CEU";
            customerDataSource.DynamicFieldList = true;
            customerDataSource.OrderMode = OrderMode.OrderBy;

            query.DataSources[0] = customerDataSource;
            query.OrderByFields = new QueryDataOrderByMetadata[]{
                new QueryDataOrderByMetadata(){ DataSource="AccountNum", FieldName="AccountNum",SortOrder=SortOrder.Ascending}
            };

            dataSet = client.ExecuteQuery(query, ref paging);

but the same code when runs in MVC WebAPI gives error

System.ServiceModel.FaultException`1 was unhandled by user code
  HResult=-2146233087
  Message=Page size 'PositionBasedPaging.StartingPosition' is out of range.
Parameter name: PositionBasedPaging.StartingPosition
  Source=mscorlib
  Action=http://schemas.microsoft.com/net/2005/12/windowscommunicationfoundation/dispatcher/fault
  StackTrace:
    Server stack trace:
       at System.ServiceModel.Channels.ServiceChannel.ThrowIfFaultUnderstood(Message reply, MessageFault fault, String action, MessageVersion version, FaultConverter faultConverter)
       at System.ServiceModel.Channels.ServiceChannel.HandleReply(ProxyOperationRuntime operation, ProxyRpc& rpc)
       at System.ServiceModel.Channels.ServiceChannel.Call(String action, Boolean oneway, ProxyOperationRuntime operation, Object[] ins, Object[] outs, TimeSpan timeout)
       at System.ServiceModel.Channels.ServiceChannelProxy.InvokeService(IMethodCallMessage methodCall, ProxyOperationRuntime operation)
       at System.ServiceModel.Channels.ServiceChannelProxy.Invoke(IMessage message)
    Exception rethrown at [0]:
       at System.Runtime.Remoting.Proxies.RealProxy.HandleReturnMessage(IMessage reqMsg, IMessage retMsg)
       at System.Runtime.Remoting.Proxies.RealProxy.PrivateInvoke(MessageData& msgData, Int32 type)
       at SL_AX_MVC_WebAPI.QueryService.IQueryService.ExecuteQuery(ExecuteQueryRequest request)
       at SL_AX_MVC_WebAPI.QueryService.QueryServiceClient.SL_AX_MVC_WebAPI.QueryService.IQueryService.ExecuteQuery(ExecuteQueryRequest request) in d:\Projects\SL_AX_MVC\SL_AX_MVC_WebAPI\Service References\QueryService\Reference.cs:line 5269
       at SL_AX_MVC_WebAPI.QueryService.QueryServiceClient.ExecuteQuery(QueryMetadata queryMetadata, Paging& paging) in d:\Projects\SL_AX_MVC\SL_AX_MVC_WebAPI\Service References\QueryService\Reference.cs:line 5276
       at SL_AX_MVC_WebAPI.Repositories.CustomerRepository.getCustomers(Int32 skip, Int32 take) in d:\Projects\SL_AX_MVC\SL_AX_MVC_WebAPI\Repositories\CustomerRepository.cs:line 108
       at SL_AX_MVC_WebAPI.Repositories.CustomerRepository.Get(Int32 skip, Int32 take) in d:\Projects\SL_AX_MVC\SL_AX_MVC_WebAPI\Repositories\CustomerRepository.cs:line 47
       at SL_AX_MVC_WebAPI.Controllers.CustomerController.Get(Int32 skip, Int32 take) in d:\Projects\SL_AX_MVC\SL_AX_MVC_WebAPI\Controllers\CustomerController.cs:line 31
       at lambda_method(Closure , Object , Object[] )
       at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.<>c__DisplayClass13.<GetExecutor>b__c(Object instance, Object[] methodParameters)
       at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.ActionExecutor.Execute(Object instance, Object[] arguments)
       at System.Web.Http.Controllers.ReflectedHttpActionDescriptor.<>c__DisplayClass5.<ExecuteAsync>b__4()
       at System.Threading.Tasks.TaskHelpers.RunSynchronously[TResult](Func`1 func, CancellationToken cancellationToken)
  InnerException:

Any help ? i have wasted my time to tackle with this issue but no success...

Answer 1

Problem Solved! When using in WebAPI, QueryService of Dynamics AX 2012 needs additional properties to provide value true for whatever property is given. These properties are Post-fix with name "Specified". These properties must be given value true otherwise exception will be thrown or no data will return.

Correct Code is below:

QueryServiceClient client = new QueryServiceClient();

        DataSet dataSet;
        Paging paging = new PositionBasedPaging() { StartingPosition = 1, NumberOfRecordsToFetch = 10, NumberOfRecordsToFetchSpecified = true, StartingPositionSpecified = true };

        QueryMetadata query = new QueryMetadata();
        QueryDataSourceMetadata customerDataSource;

        query.QueryType = QueryType.Join;
        query.DataSources = new QueryDataSourceMetadata[1];

        customerDataSource = new QueryDataSourceMetadata();
        customerDataSource.Name = "AccountNum";
        customerDataSource.Enabled = true;
        customerDataSource.FetchMode = FetchMode.OneToOne;
        customerDataSource.Table = "CustTable";
        customerDataSource.Company = "CEU";
        customerDataSource.DynamicFieldList = true;
        customerDataSource.OrderMode = OrderMode.OrderBy;

        customerDataSource.EnabledSpecified =
        customerDataSource.FetchModeSpecified =
        customerDataSource.DynamicFieldListSpecified =
        customerDataSource.OrderModeSpecified = true;

        query.DataSources[0] = customerDataSource;
        query.OrderByFields = new QueryDataOrderByMetadata[]{
            new QueryDataOrderByMetadata(){ DataSource="AccountNum", FieldName="AccountNum",SortOrder=SortOrder.Ascending}
        };

        dataSet = client.ExecuteQuery(query, ref paging);