February 3, 2011

Select Query LINQ To SQL Example

For Using Linq to Sql In VS2008
1.) Add New Item from Solution Explorer
2.) Select LinqtoSql Class from template ,Name it
3.) Above will generate .dbml file
4.) From server Explorer Add New Connection
5.) Drag the tables(those  you want to interact from the application ) from Serverexplorer to .dbml page
6.) Save .dbml File
7.) LINQ Mapping will be automatically done with above steps

Now you can use the LINQ for communicating with the above tables
Now in Simpler terms
.dbml file class will be the database Class
Tables which u dragged on to .dbml file will be Table Classes
columns in above tables will be Properties of the above classes

Below is the Example of Selecting Records From DB Using LINQ

Default.aspx

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>


<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">


<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
    <title>Untitled Page</title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
    
    </div>
    <asp:GridView ID="GridView1" runat="server">
    </asp:GridView>
    </form>
</body>
</html>


Default.aspx.cs



using System;
using System.Data;
using System.Configuration;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Web.UI.HtmlControls;
using System.Linq;
public partial class _Default : System.Web.UI.Page 
{
    protected void Page_Load(object sender, EventArgs e)
    {
       //autogenerated DataClassesDataContext's object when dragged Tables on DataClasses.dbml
        DataClassesDataContext db = new DataClassesDataContext();


        var results = from o in db.Orders
                      select o;
        GridView1.DataSource = results;
        GridView1.DataBind();




    }
}

Orders is table in my DB 
Below is the o/p

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