LINQ in ASP .Net

LINQ quries :

protected void Page_Load(object sender, EventArgs e)
{
    if (!IsPostBack)
    {
        Dataset dataContext = 
            new Dataset();

       //bind tables or data source in dataset

        var query = from contact in dataContext.tablename
          where tablename.columnname==1
          select contact;

        GridView1.DataSource = query;
        GridView1.DataBind();
    }
}

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Get IP Address of current system

Get IP Address :

string ip_address = HttpContext.Current.Request.UserHostAddress.ToString();

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get host name :

string hostName = System.Net.Dns.GetHostName();

Create the session in ASP .Net

//Create the session 

Session["Name"] = "Rohit Prakash";
//orSession.Add("Name","Rahul");

//retrieving the session any where in the application/page

string Name = (string)Session["Name"];


Off - No session state will be stored
InProc - (The Default) Session state exists within the process the web is using
StateServer - Session data is sent to the configured stateserver service
SQLServer - Session data is store in the configured sql server database

Introduction of LINQ in ASP .Net

Language-Integrated Query (LINQ)

Language-Integrated Query (LINQ) is an innovation introduced in Visual Studio 2008 and .NET Framework version 3.5 that bridges the gap between the world of objects and the world of data.

Traditionally, queries against data are expressed as simple strings without type checking at compile time or IntelliSense support. Furthermore, you have to learn a different query language for each type of data source: SQL databases, XML documents, various Web services, and so on. LINQ makes a query a first-class language construct in C# and Visual Basic. You write queries against strongly typed collections of objects by using language keywords and familiar operators. The following illustration shows a partially-completed LINQ query against a SQL Server database in C# with full type checking and IntelliSense support.

In Visual Studio you can write LINQ queries in Visual Basic or C# with SQL Server databases, XML documents, ADO.NET Datasets, and any collection of objects that supportsIEnumerable or the generic IEnumerable<T> interface. LINQ support for the ADO.NET Entity Framework is also planned, and LINQ providers are being written by third parties for many Web services and other database implementations.