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 select data from XML with where clause using LINQ to XML?
In simple terms "It provides flexibility to pull out the data from XML using a LINQ query by filtering the data based on element."
Step 1: Create a new "ASP.Net Web Forms Application", as in:
![Output1.jpg]()
Step 2: The complete code of Employee.xml looks like this:
<?xml version="1.0" encoding="utf-8" ?>
<Employees>
<Employee>
<FirstName>Vijay</FirstName>
<Age>26</Age>
</Employee>
<Employee>
<FirstName>Ram Reddy</FirstName>
<Age>29</Age>
</Employee>
</Employees>
Step 3: The complete code of webform1.aspx looks like this:
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="WebForm1.aspx.cs" Inherits="LINQtoXMLSelectApp.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">
<center>
<div>
<table>
<tr>
<td colspan="2">
<asp:Label ID="Label1" runat="server" Text="Select Data with Where Clause using LINQ to XML"
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="Select Data" Font-Names="Verdana" Width="213px"
BackColor="Orange" Font-Bold="True" OnClick="Button1_Click" />
</td>
</tr>
<tr>
<td colspan="2" align="center">
<br />
<asp:GridView ID="GridView1" runat="server" BackColor="LightGoldenrodYellow" BorderColor="Tan"
BorderWidth="1px" CellPadding="2" EnableModelValidation="True" ForeColor="Black"
GridLines="None" AutoGenerateColumns="False">
<AlternatingRowStyle BackColor="PaleGoldenrod"></AlternatingRowStyle>
<FooterStyle BackColor="Tan"></FooterStyle>
<HeaderStyle BackColor="Tan" Font-Bold="True"></HeaderStyle>
<PagerStyle HorizontalAlign="Center" BackColor="PaleGoldenrod" ForeColor="DarkSlateBlue">
</PagerStyle>
<SelectedRowStyle BackColor="DarkSlateBlue" ForeColor="GhostWhite"></SelectedRowStyle>
<Columns>
<asp:BoundField DataField="FirstName" HeaderText="First Name" ReadOnly="true" />
<asp:BoundField DataField="Age" HeaderText="Age" ReadOnly="true" />
</Columns>
</asp:GridView>
</td>
</tr>
</table>
</div>
</center>
</form>
</body>
</html>
Step 4: 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;
using System.Xml.Linq;
namespace LINQtoXMLSelectApp
{
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, EventArgs e)
{
}
protected void Button1_Click(object sender, EventArgs e)
{
XDocument document = XDocument.Load(@"c:\users\administrator\documents\visual studio 2010\Projects\LINQtoXMLSelectApp\LINQtoXMLSelectApp\Employee.xml");
var query = from r in document.Descendants("Employee") where (int)r.Element("Age") > 27 select new
{
FirstName = r.Element("FirstName").Value, Age = r.Element("Age").Value };
GridView1.DataSource = query;
GridView1.DataBind();
}
}
}
Step 5: The output of the application looks like this:
![Output2.png]()
Step 6: The filtered data selected from XML looks like this:
![Output3.png]()
I hope this article is useful for you.