Linq With SQL

Posted by on January 17, 2010 Leave a comment (0) Go to comments

Introduction:
In this article,we are going to discuss about how to use LINQ against SQL datasource.

Main:

Linq-to-SQL is an Object/relational (O/R) mapping implementation that allows developers and architectures to model a relation database using .NET classes.

Operations on classes are translated to commands for Crate/Read/Update/Delete (CRUD) statements that modify the underlying database through a regular connection.

LINQ_To_SQL.aspx,

<%@ Page Language="C#" AutoEventWireup="true"  CodeFile="Default.aspx.cs" Inherits="_Default" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "<a href="http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd</a>">
 
<html xmlns="<a href="http://www.w3.org/1999/xhtml">http://www.w3.org/1999/xhtml</a>">
<head runat="server">
    <title>Untitled Page</title>
    <style type="text/css">
        .newStyle1
        {
            position: absolute;
        }
        #form1
        {
            height: 604px;
        }
    </style>
</head>
<body>
    <form id="form1" runat="server" style="position: absolute">
    <div class="newStyle1">
 
        <asp:Button ID="Button1" runat="server" Font-Size="Large" Height="67px"
            onclick="Button1_Click" Text="Get using Linq code" Width="195px" />
        <asp:GridView ID="GridView1" runat="server" AllowPaging="True"
            AllowSorting="True" AutoGenerateColumns="False" DataKeyNames="deptno"
            DataSourceID="LinqDataSource1">
            <Columns>
                <asp:BoundField DataField="deptno" HeaderText="deptno" ReadOnly="True"
                    SortExpression="deptno" />
                <asp:BoundField DataField="dname" HeaderText="dname" SortExpression="dname" />
                <asp:BoundField DataField="loc" HeaderText="loc" SortExpression="loc" />
            </Columns>
        </asp:GridView>
        <asp:GridView ID="GridView2" runat="server" CellPadding="4" ForeColor="#333333"
            GridLines="None">
            <FooterStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
            <RowStyle BackColor="#F7F6F3" ForeColor="#333333" />
            <PagerStyle BackColor="#284775" ForeColor="White" HorizontalAlign="Center" />
            <SelectedRowStyle BackColor="#E2DED6" Font-Bold="True" ForeColor="#333333" />
            <HeaderStyle BackColor="#5D7B9D" Font-Bold="True" ForeColor="White" />
            <EditRowStyle BackColor="#999999" />
            <AlternatingRowStyle BackColor="White" ForeColor="#284775" />
        </asp:GridView>
        <br />
        <br />
        <asp:LinqDataSource ID="LinqDataSource1" runat="server"
            ContextTypeName="DeptClassDataContext" TableName="depts"
            Where="deptno &amp;gt; @deptno">
            <WhereParameters>
                <asp:Parameter DefaultValue="10" Name="deptno" Type="Int32" />
            </WhereParameters>
        </asp:LinqDataSource>
 
    </div>
    </form>
</body>
</html>

LINQ_To_SQL.aspx.cs,

using System;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Web;
using System.Web.Security;
using System.Web.UI;
using System.Web.UI.HtmlControls;
using System.Web.UI.WebControls;
using System.Web.UI.WebControls.WebParts;
using System.Xml.Linq;
 
public partial class _Linq_To_Sql : System.Web.UI.Page
{
    protected void Page_Load(object sender, EventArgs e)
    {
 
    }
    protected void Button1_Click(object sender, EventArgs e)
    {
        DeptClassDataContext dc = new DeptClassDataContext();
        var data = from c in dc.depts
                   where c.loc=="hyd"
                   orderby c.dname
                   select c;
 
        GridView2.DataSource = data;
        GridView2.DataBind();
    }
}