Wcf Data Service fails when more than 8 properties are specified in the 'select=' portion of the URI

Question

Hi:

I am using WCF Data Service   and   Oracle  

EF Provider is  ODAC11.2 Release 4

here is my code

var q = from c in this.ctx.SALESORDER_ITEM         
                   select new
                   {
                       c.SORDERDETAILID,
                       c.IID,c.DMFLAG,c.OWNERID,c.SKUID,c.SKU_ID,c.TRADENO,c.SOURCEID,c.SORDERID                 
                   };

excetion:

InvalidOperationException: An error occurred for this query during batch execution. See the inner exception for details

The inner exception is null, but the DataServiceClientException states: Value cannot be null Parameter name: value 

the exception is thrown in base.OnStartProcessingRequest(args) method (overridden).

Here is the call stack as well:

   at System.Data.Services.WebUtil.CheckArgumentNull[T](T value, String parameterName)

   at System.Data.Services.Internal.ProjectedWrapper.set_PropertyNameList(String value)

   at lambda_method(Closure , Shaper )

   at System.Data.Common.Internal.Materialization.Coordinator`1.ReadNextElement(Shaper shaper)

   at System.Data.Common.Internal.Materialization.Shaper`1.SimpleEnumerator.MoveNext()

   at System.Data.Services.Internal.ProjectedWrapper.EnumeratorWrapper.MoveNext() 

at System.Data.Services.DataService`1.SerializeResponseBody(RequestDescription description, IDataService dataService)

   at System.Data.Services.DataService`1.HandleNonBatchRequest(RequestDescription description)

   at System.Data.Services.DataService`1.HandleRequest()

 
 Is there a max number of properties in $select  statement

I think  may be  it is oracle provider's problem ,but  i don't konw how to debug it   Can anyone help me

Any help is greatly appreciated

Answer 1

This is very likely Oracle provider problem. We do have a test for more than 8 (a lot more) over SQL Server and it works just fine. But I don't know how to debug the Oracle provider either.

Thanks,

---

Vitek Karas [MSFT]

Answer 2

thanks Vitek,  but  I also find this postArgumentNullException when querying many fields. it's very similar to my problem but with another kind of reason.  Is there any way I can confirm the actual reason ?

Also this  Wcf Data Service fails when

Really appreciated!

 

Answer 3

Hi Vitek,

I haven't soved this problem yet,I report this to oracle onp.net forum, it's here

 And in another post ,it says 

Unfortunately, this is designed behaviour. 
We are unable to change OData projection rules.

Do you agree with that?

Please help me , thinks  a lot.

Answer 4

Hi,

I would have to disagree. OData on its own doesn't limit projections at all. WCF DS uses some rather complex lambda expressions to translate lot of projections (>8) to the LINQ expression, but it should still work for any number of projections.

We debugged this problem on our side a little and it seems that the DevArt provider projects a null value in place of an empty string in one of the cases. Another case of this happening is described in the thread: http://social.msdn.microsoft.com/Forums/en-US/adodotnetdataservices/thread/e74ea4d1-a262-4326-8529-c146a3acfb6d.

We are currently looking into possible solutions.

Thanks,

---

Vitek Karas [MSFT]

Answer 5

This issue is still happening in WCF Data Services 5.1.0 RC

Answer 6

I did faces the same problem in other version of service and found a solution at devart forums.

Just add one line to service init code 

public static void InitializeService(DataServiceConfiguration config)
        {
//  ….. Other code
            Devart.Data.Oracle.Entity.OracleEntityProviderServices.HandleNullStringsAsEmptyStrings = true;
        }

For me it works , Detailed Reference can be found at 

http://ashwini47-tts.blogspot.com/2012/05/wcf-data-service-fails-selecting-more.html

Answer 7

Please refer to WCF DataServices 5.0.2 nuget release - http://nuget.org/packages/Microsoft.Data.Services/5.0.2-rc - that has a fix for this issue.