Delete Data Using Code First Approach

Introduction

This article shows how to delete data using the Code First approach.

Create an ASP.Net web application as in the following:

Before delete

Employee.cs

Employeecontext.cs

using System;
using System.Collections.Generic;
using System.Data.Entity;
using System.Linq;
using System.Web;
namespace Insert_Data___Code_Frist_Approach
{
public class EmployeeContext : DbContext
{
public EmployeeContext()
: base("EmployeeConn")
{
Database.SetInitializer<EmployeeContext>(new CreateDatabaseIfNotExists<EmployeeContext>());
}
public DbSet<Employee> Employees { get; set; }
}
}

Web.config

<connectionStrings>
<add name="EmployeeConn"
connectionString="Data Source=WIN-B4KJ8JI75VF;Initial Catalog=EmployeeDB;Integrated Security=true"
providerName="System.Data.SqlClient"/>
</connectionStrings>

Webform1.aspx

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="Delete_Data___EF_Code_First_Approach.WebForm1" %>
<!DOCTYPE html>
<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
<title></title>
</head>
<body>
<form id="form1" runat="server">
<div>
<table>
<tr>
<td>
<asp:Label ID="Label1" runat="server" Text="Delete Data - EF Code First Approach" Font-Bold="true"></asp:Label>
</td>
</tr>
</table>
<br />
<br />
<table>
<tr>
<td>
<asp:Label ID="Label6" runat="server" Text="Please Enter Id: " ForeColor="Brown"
Font-Bold="true" Font-Italic="true"></asp:Label>
</td>
<td>
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
</td>
</tr>
<tr>
<td colspan="2">
<asp:Button ID="Button1" runat="server" Text="Delete Data"
BackColor="Orange" Font-Bold="true" OnClick="Button1_Click" />
<br />
<br />
</td>
</tr>
</table>
<br />
<br />
<table>
<tr>
<td colspan="3">
<asp:Label ID="Label5" runat="server" ForeColor="Red" Font-Bold="true"></asp:Label>
</td>
</tr>
</table>
</div>
</form>
</body>
</html>

Webform1.aspx.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.UI;
using System.Web.UI.WebControls;
namespace Delete_Data___EF_Code_First_Approach
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
EmployeeContext empContext = new EmployeeContext();
var empID = int.Parse(TextBox1.Text);
var emp = empContext.Employees.Where(a => a.Id.Equals(empID)).SingleOrDefault();
empContext.Employees.Remove(emp);
empContext.SaveChanges();
}
}
}

The output of the application looks as in the following.