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

  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Web;
  5. using System.ComponentModel.DataAnnotations;
  6. using System.ComponentModel.DataAnnotations.Schema;
  8. namespace Insert_Data___Code_Frist_Approach
  9. {
  10. public class Employee
  11. {
  13. public Employee()
  14. {
  15. }
  17. [Key]
  18. [DatabaseGenerated(DatabaseGeneratedOption.Identity)]
  19. public int Id { get; set; }
  20. public string FirstName { get; set; }
  21. public string LastName { get; set; }
  22. public int Age { get; set; }
  23. }
  24. }
Employeecontext.cs
  1. using System;
  2. using System.Collections.Generic;
  3. using System.Data.Entity;
  4. using System.Linq;
  5. using System.Web;
  7. namespace Insert_Data___Code_Frist_Approach
  8. {
  9. public class EmployeeContext : DbContext
  10. {
  11. public EmployeeContext()
  12. : base("EmployeeConn")
  13. {
  14. Database.SetInitializer<EmployeeContext>(new CreateDatabaseIfNotExists<EmployeeContext>());
  15. }
  17. public DbSet<Employee> Employees { get; set; }
  18. }
  19. }
Web.config
  1. <connectionStrings>
  2. <add name="EmployeeConn"
  3. connectionString="Data Source=WIN-B4KJ8JI75VF;Initial Catalog=EmployeeDB;Integrated Security=true"
  4. providerName="System.Data.SqlClient"/>
  5. </connectionStrings>
Webform1.aspx
  1. <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="Delete_Data___EF_Code_First_Approach.WebForm1" %>
  3. <!DOCTYPE html>
  5. <html xmlns="http://www.w3.org/1999/xhtml">
  6. <head runat="server">
  7. <title></title>
  8. </head>
  9. <body>
  10. <form id="form1" runat="server">
  11. <div>
  12. <table>
  13. <tr>
  14. <td>
  15. <asp:Label ID="Label1" runat="server" Text="Delete Data - EF Code First Approach" Font-Bold="true"></asp:Label>
  16. </td>
  17. </tr>
  18. </table>
  19. <br />
  20. <br />
  21. <table>
  22. <tr>
  23. <td>
  24. <asp:Label ID="Label6" runat="server" Text="Please Enter Id: " ForeColor="Brown"
  25. Font-Bold="true" Font-Italic="true"></asp:Label>
  26. </td>
  27. <td>
  28. <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
  29. </td>
  30. </tr>
  31. <tr>
  32. <td colspan="2">
  33. <asp:Button ID="Button1" runat="server" Text="Delete Data"
  34. BackColor="Orange" Font-Bold="true" OnClick="Button1_Click" />
  35. <br />
  36. <br />
  37. </td>
  38. </tr>
  39. </table>
  40. <br />
  41. <br />
  42. <table>
  43. <tr>
  44. <td colspan="3">
  45. <asp:Label ID="Label5" runat="server" ForeColor="Red" Font-Bold="true"></asp:Label>
  46. </td>
  47. </tr>
  48. </table>
  49. </div>
  50. </form>
  51. </body>
  52. </html>
Webform1.aspx.cs
  1. using System;
  2. using System.Collections.Generic;
  3. using System.Linq;
  4. using System.Web;
  5. using System.Web.UI;
  6. using System.Web.UI.WebControls;
  8. namespace Delete_Data___EF_Code_First_Approach
  9. {
  10. public partial class WebForm1 : System.Web.UI.Page
  11. {
  12. protected void Page_Load(object sender, EventArgs e)
  13. {
  15. }
  17. protected void Button1_Click(object sender, EventArgs e)
  18. {
  19. EmployeeContext empContext = new EmployeeContext();
  20. var empID = int.Parse(TextBox1.Text);
  21. var emp = empContext.Employees.Where(a => a.Id.Equals(empID)).SingleOrDefault();
  22. empContext.Employees.Remove(emp);
  23. empContext.SaveChanges();
  24. }
  25. }
  26. }
The output of the application looks as in the following.

Summary

In this article we saw how to delete data using the Code First approach. Happy coding!