Introduction

Today, in this article let's play around with one of the interesting and most useful concepts in LINQ to XML.

Question: What is update data to XML using LINQ to XML?

In simple terms "It provides flexibility to update data in XML with the help of a LINQ query."

Step 1: Create a new "ASP.NET Web Application"

Output1.jpg

Step 2: The complete code of Employee.xml looks like this

  1. <?xml version="1.0" encoding="utf-8"?>
  2. <Employees>
  3. <Employee>
  4. <Id>1</Id>
  5. <FirstName>Vijay</FirstName>
  6. <LastName>Prativadi</LastName>
  7. <Age>26</Age>
  8. </Employee>
  9. <Employee>
  10. <Id>2</Id>
  11. <FirstName>Sandeep</FirstName>
  12. <LastName>Reddy</LastName>
  13. <Age>28</Age>
  14. </Employee>
  15. </Employees>
Step 3: The complete code of webform1.aspx looks like this
  1. <%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="LINQtoXMLUpdateApp.WebForm1" %>
  2. <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
  3. <html xmlns="http://www.w3.org/1999/xhtml">
  4. <head id="Head1" runat="server">
  5. <title></title>
  6. </head>
  7. <body>
  8. <form id="form1" runat="server">
  9. <center>
  10. <div>
  11. <table>
  12. <tr>
  13. <td colspan="2" align="center">
  14. <asp:Label ID="Label1" runat="server" Text="Update Data using LINQ-to-XML" Font-Bold="true"
  15. Font-Size="Large" Font-Names="Verdana" ForeColor="Maroon"></asp:Label>
  16. </td>
  17. </tr>
  18. <tr>
  19. <td>
  20. <asp:Label ID="Label6" runat="server" Text="Please Enter Id" Font-Size="Large" Font-Names="Verdana"
  21. Font-Italic="true"></asp:Label>
  22. </td>
  23. <td>
  24. <asp:TextBox ID="TextBox4" runat="server"></asp:TextBox>
  25. </td>
  26. </tr>
  27. <tr>
  28. <td>
  29. <asp:Label ID="Label2" runat="server" Text="Please Enter FirstName" Font-Size="Large"
  30. Font-Names="Verdana" Font-Italic="true"></asp:Label>
  31. </td>
  32. <td>
  33. <asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
  34. </td>
  35. </tr>
  36. <tr>
  37. <td>
  38. <asp:Label ID="Label3" runat="server" Text="Please Enter LastName" Font-Size="Large"
  39. Font-Names="Verdana" Font-Italic="true"></asp:Label>
  40. </td>
  41. <td>
  42. <asp:TextBox ID="TextBox2" runat="server"></asp:TextBox>
  43. </td>
  44. </tr>
  45. <tr>
  46. <td>
  47. <asp:Label ID="Label4" runat="server" Text="Please Enter Age" Font-Size="Large" Font-Names="Verdana"
  48. Font-Italic="true"></asp:Label>
  49. </td>
  50. <td>
  51. <asp:TextBox ID="TextBox3" runat="server"></asp:TextBox>
  52. </td>
  53. </tr>
  54. <tr>
  55. <td colspan="2" align="center">
  56. <asp:Button ID="Button1" runat="server" Text="Update Data" Font-Names="Verdana" Width="213px"
  57. BackColor="Orange" Font-Bold="True" OnClick="Button1_Click" />
  58. </td>
  59. </tr>
  60. <tr>
  61. <td colspan="2" align="center">
  62. <asp:Label ID="Label5" runat="server" Font-Bold="true" Font-Names="Verdana"></asp:Label>
  63. </td>
  64. </tr>
  65. </table>
  66. </div>
  67. </center>
  68. </form>
  69. </body>
  70. </html>

Step 4: The complete code of webform1.aspx.cs looks like this

  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;
  7. using System.Xml.Linq;
  8. namespace LINQtoXMLUpdateApp
  9. {
  10. public partial class WebForm1 : System.Web.UI.Page
  11. {
  12. protected void Page_Load(object sender, EventArgs e)
  13. {
  14. }
  15. protected void Button1_Click(object sender, EventArgs e)
  16. {
  17. if (string.IsNullOrEmpty(TextBox4.Text) || string.IsNullOrEmpty(TextBox1.Text)|| string.IsNullOrEmpty(TextBox2.Text) || string.IsNullOrEmpty(TextBox3.Text))
  18. {
  19. Label5.Text = "Please Enter Some Values";
  20. Label5.ForeColor = System.Drawing.Color.Red;
  21. }
  22. else
  23. {
  24. XDocument document = XDocument.Load(Server.MapPath("Employee.xml"));
  25. var updateQuery = from r in document.Descendants("Employee")where r.Element("Id").Value == TextBox4.Textselect r;
  26. foreach (var query in updateQuery)
  27. {
  28. query.Element("FirstName").SetValue(TextBox1.Text);
  29. query.Element("LastName").SetValue(TextBox2.Text);
  30. query.Element("Age").SetValue(TextBox3.Text);
  31. }
  32. document.Save(Server.MapPath("Employee.xml"));
  33. Label5.Text = "Data Updated Successfully";
  34. Label5.ForeColor = System.Drawing.Color.Green;
  35. TextBox4.Text = string.Empty;
  36. TextBox1.Text = string.Empty;
  37. TextBox2.Text = string.Empty;
  38. TextBox3.Text = string.Empty;
  39. }
  40. }
  41. }
  42. }
Step 5: The output of the application looks like this

update-data-using-linq-to-xml.png

Step 6: The data updating to XML output of the application looks like this

data-using-linq-to-xml.png

Step 7: The data updated to XML looks like this

  1. <?xml version="1.0" encoding="utf-8"?>
  2. <Employees>
  3. <Employee>
  4. <Id>1</Id>
  5. <FirstName>Vijay</FirstName>
  6. <LastName>Prativadi</LastName>
  7. <Age>26</Age>
  8. </Employee>
  9. <Employee>
  10. <Id>2</Id>
  11. <FirstName>Swetha</FirstName>
  12. <LastName>Prativadi</LastName>
  13. <Age>23</Age>
  14. </Employee>
  15. </Employees>
I hope this article is useful for you.