Using WCF Data Services with Entity Framework 4.1 and Code First

re: Using WCF Data Services with Entity Framework 4.1 and Code First

Chbaeumer — Tue, 20 Dec 2011 16:08:33 GMT

Hi Jeff,

I discovered a serious bug.

I searched a whole day for the reason why my model didn't word like your example.

I always got an exception in function 'System.Data.Common.DbConnectionOptions.GetKeyValuePair(String connectionString, Int32 currentPosition, StringBuilder buffer, Boolean useOdbcRules, String& keyname, String& keyvalue)' stating that the format is not correct.

After playing around I discovered that the problem was a database name with spaces in the name. Then the connection string has additional spaces which are not correctly handled by the DbConnectionOptions parser.

After using a databasename without spaces my example worked like charm.

re: Using WCF Data Services with Entity Framework 4.1 and Code First

Hayley — Tue, 04 Oct 2011 15:19:05 GMT

Hi Jeff,

Do you know if this is possible with the June 2011 CTP and EF 4.1? I'm getting the error below:

The server encountered an error processing the request. The exception message is 'Expression of type 'System.Data.Objects.ObjectContext' cannot be used for return type 'System.Data.Objects.ObjectContext''. See server logs for more details. The exception stack trace is:

at System.Linq.Expressions.Expression.ValidateLambdaArgs(Type delegateType, Expression& body, ReadOnlyCollection`1 parameters) at System.Linq.Expressions.Expression.Lambda[TDelegate](Expression body, String name, Boolean tailCall, IEnumerable`1 parameters) at System.Data.Services.Providers.DbContextHelper.CreateDbContextAccessor(Type type) at System.Data.Services.Providers.DbContextHelper.GetDbContextAccessor(Type type) at System.Data.Services.DataService`1.CreateProvider() at System.Data.Services.DataService`1.HandleRequest() at System.Data.Services.DataService`1.ProcessRequestForMessage(Stream messageBody) at SyncInvokeProcessRequestForMessage(Object , Object[] , Object[] ) at System.ServiceModel.Dispatcher.SyncMethodInvoker.Invoke(Object instance, Object[] inputs, Object[]& outputs) at System.ServiceModel.Dispatcher.DispatchOperationRuntime.InvokeBegin(MessageRpc& rpc) at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage5(MessageRpc& rpc) at System.ServiceModel.Dispatcher.ImmutableDispatchRuntime.ProcessMessage31(MessageRpc& rpc) at System.ServiceModel.Dispatcher.MessageRpc.Process(Boolean isOperationContextSet)

re: Using WCF Data Services with Entity Framework 4.1 and Code First

nss — Thu, 25 Aug 2011 19:54:30 GMT

i am getting the followi

'System.Data.Objects.ObjectContext' does not contain a definition for 'Address' and no extension method 'Address' accepting a first argument of type 'System.Data.Objects.ObjectContext' could be found (are you missing a using directive or an assembly reference?)

below is my code.

using System;

using System.Collections.Generic;

using System.Data.Services;

using System.Data.Services.Common;

using System.Linq;

using System.ServiceModel.Web;

using System.Web;

using System.Data.Services.Client;

using System.Data.Objects;

using System.Data.Entity.Infrastructure;

using CodeFirstMVC.Models;

namespace eGate.BackOffice.WebClient.WCF_Services

{

public class WcfDataService1 : DataService<ObjectContext>

{

// This method is called only once to initialize service-wide policies.

public static void InitializeService(DataServiceConfiguration config)

{

config.SetEntitySetAccessRule("*", EntitySetRights.All);

config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V3;

}

protected override ObjectContext CreateDataSource()

{

AddressContext addrContext = new AddressContext();

// Get the underlying ObjectContext for the DbContext.

var context = ((IObjectContextAdapter)addrContext).ObjectContext;

context.ContextOptions.ProxyCreationEnabled = false;

// Return the underlying context.

return context;

}

[WebGet]

public IQueryable<Address> GetAllAddress()

{

return CurrentDataSource.Address;

}

re: Using WCF Data Services with Entity Framework 4.1 and Code First

Sam — Thu, 14 Jul 2011 12:10:16 GMT

the error could be access rights on the sql database.

re: Using WCF Data Services with Entity Framework 4.1 and Code First

Jamie — Tue, 31 May 2011 14:39:34 GMT

Does the DataService now work against an interface? Or literally types derived from ObjectContext and DataContext?

re: Using WCF Data Services with Entity Framework 4.1 and Code First

Sam — Wed, 25 May 2011 14:46:59 GMT

I tried hosting a wcf data service using the local iis web server. whenever i try viewing the service in browser i receive the following error: Request Error - The server encountered an error processing the request. See server logs for more details. I, however, am able to access the service using the default Visual Studio Development Server

re: Using WCF Data Services with Entity Framework 4.1 and Code First

Darren — Thu, 05 May 2011 15:41:39 GMT

Matt,

From what I understand in order to take advantage of the database creation, you need to use SQLExpress in order to generate the initial DB.... Im not quite sure as to the reasoning behind it, but whenever I try to use the DB initialization side, on a -non-sqlexpress instance I get the same error.

re: Using WCF Data Services with Entity Framework 4.1 and Code First

william simons — Fri, 01 Apr 2011 20:48:12 GMT

It would be nice to see a wcf ria example...Is this possible??

re: Using WCF Data Services with Entity Framework 4.1 and Code First

Fred — Wed, 30 Mar 2011 13:06:59 GMT

How about somebody doing a model first, winform, datagridview, master/detail, observable example. I have spent considerable time trying to piece this together from all these blogs and I have not been successful. Seems to me this would be fairly common scenrio.

re: Using WCF Data Services with Entity Framework 4.1 and Code First

Matt — Wed, 23 Mar 2011 19:53:13 GMT

After following along with the instructions given here, I'm encountering an error that I don't understand. This comes up as soon as I run the service.

Request Error

The server encountered an error processing the request. The exception message is 'Model compatibility cannot be checked because the database does not contain model metadata. Ensure that IncludeMetadataConvention has been added to the DbModelBuilder conventions.'.

The only thing I did differently from the instructions above is to use my own connection string instead of the default (which would use SQLEXPRESS). I named the connection string the same as the context name, which I saw I would need to do from another blog. This is how it appears in the web.config:

This points to an empty database with no tables, etc. I was expecting the tables corresponding to Patients and LabResults to be created in this empty database.

Anyhow, if you have any recommendations I'd really appreciate it.

Thanks,

Matt