Adding/Creating data to OData/Wcf Data Service batch explained

I want to show you how to “upload” data to a OData Service, that is make a Http POST from client to your service. For this example I started a new Project by adding an AdventureWorks Entity Model and configuring it to a Wcf Data Service. How to you can read at:msdn (Don’t worry, this is about the Northwind DB, instead choose the AdventureWorks DB, if you not yet downloaded: check this!

Somehow the wcf data service will look like:

using System.Collections.Generic;
using System.Data.Services;
using System.Linq;
using System.ServiceModel.Web;
using System.Web;
using System.Linq.Expressions;
using System.Data.Services.Common;


namespace TestAdventureWorksDataServices
{
    public class AdventureService : DataService<AdventureWorksEntities>
    {
        // This method is called only once to initialize service-wide policies.
        public static void InitializeService(DataServiceConfiguration config)
        {
            // TODO: set rules to indicate which entity sets and service operations are visible, updatable, etc.
            // Examples:
            config.SetEntitySetAccessRule("*", EntitySetRights.All);
            // config.SetServiceOperationAccessRule("MyServiceOperation", ServiceOperationRights.All);
            config.DataServiceBehavior.MaxProtocolVersion = DataServiceProtocolVersion.V2;
            config.UseVerboseErrors = false;
        }

        protected override void HandleException(HandleExceptionArgs args)
        {
            throw new DataServiceException(args.Exception.InnerException.Message, args.Exception);
        }

     
    }
}

Once we’ve setup our service, it’s time for a client that makes some calls to it. First add a new project to the solution (ConsoleApplication for now) and make a ServiceReference to the service.
In this example we want to add 3 new products and persist them in the DB producttable. For the last part we don’t have to worry, since the Entity Framework will handle this all.
Take a look at the client:

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data.Services.Client;

namespace Client
{
    using Client.AdventureWorksServiceReference;

    class Program
    {
        private static AdventureWorksEntities _context = null;


        static void Main(string[] args)
        {
            _context = new AdventureWorksEntities(new Uri("http://ipv4.fiddler:51824/AdventureService.svc"));

            var product1 = Product.CreateProduct(0, "My Test Product 1", "1234", true, true, 1, 1, 100, 200, 3,
                                                DateTime.Now, new Guid("E29C16AE-908A-4F53-8E19-DC2CFDDF08A0"), DateTime.Now);

            var product2 = Product.CreateProduct(0, "My Test Product 2", "5678", true, true, 1, 1, 200, 300, 3,
                                     DateTime.Now, new Guid("1B9689D6-CCFF-40C3-AA0F-1AC3C5951738"), DateTime.Now);

            var product3 = Product.CreateProduct(0, "My Test Product 3", "9876", true, true, 1, 1, 300, 400, 3,
                         DateTime.Now, new Guid("{0B677FB4-890E-4FAF-AD6A-7477D5703E6E}"), DateTime.Now);

            var collection = new DataServiceCollection<Product>(_context);
            collection.Add(product1);
            collection.Add(product2);
            collection.Add(product3);
            _context.SaveChanges();

            Console.Read();


            //remove products to omit unique constraint next time running this app:
            collection.Remove(product1);
            collection.Remove(product2);
            collection.Remove(product3);
            _context.SaveChanges();

            Console.WriteLine("Deleted. Sorry, changed my mind!");
            Console.Read();


        }
    }
}

A short walkthrough of what is happening here.
First, take note of instead of setting up the context by calling “http://localhost:51824/AdventureService.svc” we include “http://ipv4.fiddler:51824/AdventureService.svc”. This is done so that later on we can monitor our calls in Fiddler.
When the application fires, a context of our service is setup, which will track all changes. In the end, if we agree with those changes we can call “context.SaveChanges()”;
By calling SaveChanges() requests are finally made to store the products. Let’s take a look in Fiddler:

As you see, there are 3 requests made to the service. Note!: by calling SaveChanges() only once.
Now let’s do it again, but change some code:
change following line:

_context.SaveChanges();

into:

_context.SaveChanges(SaveChangesOptions.Batch);

check this out in fiddler and you’ll notify the call is only made once: