Question

I am beginner in C#.

Simple Example of bigger case:

Input:

<?xml version="1.0" encoding="utf-8"?>
 <products>
  <product>
   <id>1</id>
   <name>John</name>
  </product>
  <product>
   <id>2</id>
   <name>Tom</name>
  </product>
  <product>
   <id>3</id>
   <name>Sam</name>
  </product>
 </products>
</xml>

Output(for id=1):

<id>2</id>
<name>Tom</name>

My part code try psedocode:

XDocument doc=XDocument.Parse(".............");

 var els= doc.Descendants("product");
 foreach(e in els){
     node=e.Element("id");
     if(2==node.Value){
     return e;
   }
 }

Please help,

Thanks

Answer 1

Currently your xml file is not well-formatted – remove closing </xml> tag from your file to make it valid. And here is the query:

int id = 1;
XDocument xdoc = XDocument.Load(path_to_xml);
var product = xdoc.Descendants("product")
                  .Where(p => (int)p.Element("id") == id)
                  .SingleOrDefault();

This query will return whole <product> element or null if match not found.

Also I believe product name will be enough for you to select (because you already have product id):

var name = xdoc.Descendants("product")
               .Where(p => (int)p.Element("id") == id)
               .Select(p => (string)p.Element("name"))
               .SingleOrDefault();

Returns Tom for id = 2