Question

I’ve been playing around with XML a little, trying to learn how it works, and ran into an odd problem. Sometimes, when I query my XML file, I don’t get results that I know exist. In fact, the only one I do get results for is the very first entry. The following is some example XML entries and a small function to see if a user exists.

<users>
  <user>
    <username>a</username>
    <firstname>a</firstname>
    <lastname>a</lastname>
  </user>
  <user>
    <username>b</username>
    <firstname>b</firstname>
    <lastname>b</lastname>
  </user>
  <user>
    <username>rawr</username>
    <firstname>a</firstname>
    <lastname>a</lastname>
  </user>
</users>

>

private bool FindUser(string username)
{
        XDocument doc = XDocument.Load(filePath);


        var data = from item in doc.Descendants("users")
                   where item.Element("user").Element("username").Value == username.ToLower()
                   select new
                   {
                       usernameEle = item.Element("user").Element("username").Value
                   };

        var p = data.FirstOrDefault();
        if (p != null)
            return true;
        else
            return false;
}

If I try to search for the user “a”, it returns true. If I do a search for any other username, it returns false.

I’m sure there is a simple solution but it is eluding me! Any help would be great.

Answer 1

I figured out the answer… but I’m not sure WHY this worked. I’m still somewhat new to XML…

I changed “item.Element(“user”).Element(“username”).Value” to “item.Element(“username”).Value”. Also changed “from item in doc.Descendants(“users”)” to “from item in doc.Descendants(“user”)”

var data = from item in doc.Descendants("users")
           where item.Element("user").Element("username").Value == username.ToLower()
           select new
           {
               usernameEle = item.Element("user").Element("username").Value
           };

to

var data = from item in doc.Descendants("user")
           where item.Element("username").Value == username.ToLower()
           select new
           {
               usernameEle = item.Element("username").Value
           };

It is now able to retrieve more than just the first entry. If I search b, or rawr, I get the appropriate results.

Odd.