Introduction
Today, in this article let's play around with an interesting and very useful concept in LINQ.
Question: What is truncating a table using LINQ?
In simple terms "It deletes all the data from a table based on the requested entity query".
Step 1: Create a new web application
Step 2: The complete code of WebForm1.aspx looks like this:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="Truncate_Table_LINQ_App.WebForm1" %>
<!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 id="Head1" runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<center>
<div>
<table>
<tr>
<td colspan="2" align="center">
<asp:Label ID="Label1" runat="server" Text="Truncate Table LINQ App - Select Data"
Font-Bold="true" Font-Size="Large" Font-Names="Verdana" ForeColor="Maroon"></asp:Label>
</td>
</tr>
<tr>
<td colspan="2" align="center">
<asp:Button ID="Button1" runat="server" Text="Truncate Table Data" Font-Names="Verdana"
Width="213px" BackColor="Orange" Font-Bold="True" OnClick="Button1_Click" />
</td>
</tr>
</table>
</div>
</center>
</div>
</form>
</body>
</html>
Step 3: The complete code of WebForm1.aspx.cs looks like this:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;namespace Truncate_Table_LINQ_App
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
var query = from r in objContext.Persons select r;
objContext.Persons.DeleteAllOnSubmit(query);
objContext.SubmitChanges();
}
#region Instance MembersDataClasses1DataContext objContext = new DataClasses1DataContext();
#endregion
}
}
Step 4: The output of the application looks like this:
I hope this article was useful for you.