Entity Service is Independent Service?

Entity Service is Independent Service--àworks for any Provider:

Ex: SqlClient,OracleClient,OledbClient….ect.

We know that Entity Framework Designer by default generates every member as DataMemberAttributes.  So Every member  is serializable.*****(using DataContract Serializer);

And

Now we can create a service( Independent Service).  Which work for any Underlaying Provider(underlaying database). Because of Conceptual model.

Same service works for ----MS-Sql Server, OracleClient, OledbClient,MySql…ect.

then
Now add –new Item---WCF Service—EntityService-àEntityService.cs and IEntityService.cs

at
IEntityService:

[ServiceContract]

    public interface IEntityService

    {

        [OperationContract]

        [FaultContract(typeof(CustomFaultMsg))]

        Employees GetCategory(int Empid);

    }

    [DataContract]

    public struct CustomFaultMsg

    {

        [DataMember]

        public string MyCustomErrMsg { get; set; }

         }

EntityService :IEntityService

better to write as single northwind service instance for multiple clients at ServiceImplementation: more 

readable/clear 

public Product GetCategory(int ProID)

        {

            NorthwindEntities context = EntityService.Instance();

            IQueryable<Product> productsupplier = context.Products.Where<Product>(t => t.ProductID == ProID);

          

           IEnumerator<Product> iers  =productsupplier.GetEnumerator();           

           while (iers.MoveNext())

           {

              

               product = new Product();

               product.ProductName = iers.Current.ProductName;

               product.QuantityPerUnit = iers.Current.QuantityPerUnit;

                //  *****If LazyLoadingisEnable=ture

               product.Supplier = new Supplier { CompanyName = iers.Current.Supplier.CompanyName };

               product.Category = new Category { CategoryName = iers.Current.Category.CategoryName };      //*******

               

               return product;                         

           }         

           return product;

       }

app.config

CommandBehavior.SequentialAccess

takes the data from the database as per alphabithacal order :
so becare about oder of database columns: datarader read in database:

now at service implementation all classes are Provider independent classes.

so we can say my service is Independent client Service. because of EntityCommand,EntityConnection, EntityDataRader.....ect.

at Client

Reference : http://msdn.microsoft.com/en-us/library/bb738684.aspx