Introduction

In this blog we will see how to perform self join using linq to sql.

Step 1: Create ASP.NET Webforms application

Webform1.aspx

  1. <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="SelfJoin_LINQtoSQL.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. <asp:GridView ID="GridView1" runat="server"></asp:GridView>
  13. </div>
  14. </form>
  15. </body>
  16. </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 SelfJoin_LINQtoSQL
  9. {
  10. public partial class WebForm1 : System.Web.UI.Page
  11. {
  12. DataClasses1DataContext objContext = new DataClasses1DataContext();
  13. protected void Page_Load(object sender, EventArgs e)
  14. {
  15. var query = (from r in objContext.Employees
  16. join s in objContext.Employees
  17. on r.EmpId equals s.DeptId
  18. select new
  19. {
  20. FirstName = r.FirstName
  21. ,LastName = r.LastName
  22. });
  24. GridView1.DataSource = query;
  25. GridView1.DataBind();
  26. }
  27. }
  28. }

Output of the application looks like this

Summary

In this blog we have seen how we can perform self join using linq to sql. Happy coding!