Read and Update XML value using “SelectSingleNode” method.

Read and Update XML value using "SelectSingleNode" method. There are multiple methods of reading XML values and lots of time we do looping and reading node values one by one, I found very good of reading xml node values directly by using proper node path. Assume you have xml  file from where you have to read the values. Read and Update node path will be changed based on the XML format.  See some example below    Sample XML 1 (File Name: "Sample.xml") <?xml version="1.0" encoding="utf-8" ?> <Root> <Employees DeptId="10">               <Info name="Ritesh" Id="100" salary="20000"></Info>               <Info name="Kumar" Id="200" salary="30000"></Info>        </Employees>        <Employees DeptId="20">               <Info name="Kitesh" Id="100" salary="10000"></Info>               <Info name="Gupta" Id="200" salary="20000"></Info>        </Employees>  </Root> C# Code for Reading XML File using System.Xml; XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load("Sample.xml"); //[OPERATION]:Read Employee info that belongs to Department Number 10 and Id is 100 XmlNode xmlNodeComponent = xmlDoc.SelectSingleNode("//Root/Employees[@DeptId='10']/Info[@Id='100']"); if (xmlNodeComponent != null) {  string empName = xmlNodeComponent.Attributes["name"].Value; // Ritesh string empId = xmlNodeComponent.Attributes["Id"].Value; // 100 string empSalary = xmlNodeComponent.Attributes["salary"].Value; // 20000 } Update XML value with new value XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load(xmlFile); XmlNode xmlNodeComponent = xmlDoc.SelectSingleNode("//Root/Employees[@DeptId ='10']/Info[@Id='100']"); if (xmlNodeComponent != null) { //[OPERATION]: Update Employee salary who is belongs to Department  Number 10 and Id is 100   xmlNodeComponent.Attributes["salary"].Value = "60000";   xmlDoc.Save(xmlFile); } Here another XML file sample with different type, the node path will be different to read node value. Sample XML 2 (File Name: "Sample.xml") <?xml version="1.0" encoding="utf-8" ?> <Root>        <Employees DeptId="10" Id="100">               <name>Ritesh Kumar</name>               <salary>2000</salary>               <DOB>23-Jun-1980</DOB>                   </Employees>        <Employees DeptId="20" Id="100">               <name>Kitesh Gupta</name>               <salary>3000</salary>               <DOB>12-Mar-1980</DOB>        </Employees> </Root> C# Code for Reading XML File using System.Xml; XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load("Sample.xml"); //[OPERATION]:Read Employee info that is belongs to Department Number 10 and Id is 100 XmlNode xmlNodeComponent = xmlDoc.SelectSingleNode("//Root/Employees[@DeptId='10'][@Id='100']"); if (xmlNodeComponent != null) { string empName = xmlNodeComponent.ChildNodes[0].InnerText; // Ritesh Kumar string empSalary = xmlNodeComponent.ChildNodes[1].InnerText; // 2000 string empDOB = xmlNodeComponent.ChildNodes[2].InnerText; // 23-Jun-1980 } Update XML value with new value XmlDocument xmlDoc = new XmlDocument(); xmlDoc.Load(xmlFile); XmlNode xmlNodeComponent = xmlDoc.SelectSingleNode(("//Root/Employees[@DeptId='10'][@Id='100']"); if (xmlNodeComponent != null) { //[OPERATION]: Update Employee salary who is belongs to Department Number 10 and Id is 100   xmlNodeComponent. ChildNodes[1].InnerText = "60000";   xmlDoc.Save(xmlFile); } Some other links for basic XML Operation http://riteshkk2000.blogspot.com/2007/07/how-to-readwrite-xml-string-in.html http://riteshk.blogspot.com/2005/03/how-to-readwrite-into-xml.html