Wriju's BLOG

.NET, Cloud and everything

Data Services (aka Astoria) : CRUD (Select / Insert / Update / Delete )

Creating Astoria is very easy and many of you might have tried that out. What important for us is to work with that data. If you are developing Visual Studio Solution then things are quite obvious as mentioned below,


Either you will have Astoria or you will create that service. I am not going in details how you can create that. Assume that you have a service running anywhere.


You create your client apps (Windows / Web) and the reference an assembly “System.Data.Services.Client”.



After that you need to create “Service Reference” like WCF / Web Service from your visual studio project. Add the required namespace on top of your code behind file where you are writing your code.



C : Create / Inserting Data


static void Main(string[] args)


{


    //Initialize the consumed Astoria Service


    DataServiceContext ctx = new DataServiceContext(new Uri(@”http://localhost:1116/TestDataService.svc/”));


 


    //This option is very important for Inserting


    ctx.MergeOption = MergeOption.AppendOnly;


 


    //Create a new object to insert


    Emp emp = new Emp() { Name = “Astoria Employee” };


 


    //Add to the collection


    ctx.AddObject(“Emp”, emp);


 


    //Commit the changes to Database


    ctx.SaveChanges();


}


U : Updating Data


static void Main(string[] args)


{


    //Initialize the consumed Astoria Service


    TestDataEntities ctx = new TestDataEntities(new Uri(@”http://localhost:1116/TestDataService.svc/”));


       


    //Create a new object to insert


    Emp emp = (from e in ctx.Emp where e.Id == 81 select e).First();


 


    //Change the Employee Name


    emp.Name = DateTime.Now.ToString();


 


    //Update the collection


    ctx.UpdateObject(emp);


 


    //Commit the changes to Database


    ctx.SaveChanges();


}


 


D : Deleting Data


static void Main(string[] args)


{


    //Initialize the consumed Astoria Service


    TestDataEntities ctx = new TestDataEntities(new Uri(@”http://localhost:1116/TestDataService.svc/”));


 


   


    //Create a new object to insert


    Emp emp = (from e in ctx.Emp where e.Id == 80 select e).First();


 


    //Delete the entity


    ctx.DeleteObject(emp);


 


    //Commit the changes to Database


    ctx.SaveChanges();


}


R : Read / Querying Astoria Service


static void Main(string[] args)


{


    //Initialize the consumed Astoria Service


    TestDataEntities ctx = new TestDataEntities(new Uri(@”http://localhost:1116/TestDataService.svc/”));


       


    //Create a new object to insert


    IEnumerable<Emp> emps = from e in ctx.Emp select e;


 


    foreach (Emp emp in emps)


    {


        Console.WriteLine(“Employee Id : [{0,2}] Name : {1}”, emp.Id, emp.Name );


    }


}


 


Namoskar!!!