Trying to delete an XML Node based on attribute value

Question

I am trying to delete one record from the XML based on some attribute value. My XML structure is given below:

<?xml version="1.0" encoding="utf-8"?>
<Users>
  <User>
    <UserId>12345</UserId>
    <FirstName>abcd</FirstName>
    <LastName>efgh</LastName>
    <Email>Hello@hello.com</Email>
    <IsAdmin>No</IsAdmin>
  </User>
  <User>
    <UserId>67890</UserId>
    <FirstName>ijklm</FirstName>
    <LastName>nopqr</LastName>
    <Email>world@world.com</Email>
    <IsAdmin>No</IsAdmin>
  </User>
  <User>
    <UserId>12678</UserId>
    <FirstName>stuv</FirstName>
    <LastName>wxyz</LastName>
    <Email>foo@bar.com</Email>
    <IsAdmin>Yes</IsAdmin>
  </User>
</Users>

E.g if attribute value is 12345 it should delete the below record from the XML.

<User>
        <UserId>12345</UserId>
        <FirstName>abcd</FirstName>
        <LastName>efgh</LastName>
        <Email>Hello@hello.com</Email>
        <IsAdmin>No</IsAdmin>
      </User>

I tried below code but I am not able to delete anything from the XML.

string path = Server.MapPath("~/XML/users.xml");
                XElement xEle = XElement.Load(path);
                var qry = from element in xEle.Descendants()
                          where (string)element.Attribute("UserId").Value == "12345"
                          select element;
                if (qry.Count() > 0)
                    qry.First().Remove();
                xEle.Save(path);

I am unable to figure this out. Any help with be appreciated. Thank you

http://stackoverflow.com/questions/3229330/deleting-specific-node-in-xml — adiga, Jan 08 '16 at 12:47

dbc · Accepted Answer · 2016-01-08T12:50:29.910

1

<UserId>12345</UserId> is a nested sub-element of <User>, not an attribute. See XML attribute vs XML element to see the difference.

Thus you need to do:

        var userId = "12345";

        var qry = from element in xEle.Descendants("User")
                  where (string)element.Element("UserId") == userId
                  select element;
        var first = qry.FirstOrDefault();
        if (first != null)
            first.Remove();

Incidentally, by calling both Count() and First(), you are evaluating your query twice. FirstOrDefault() returns the first matching element, or null if the enumerable is empty, and is thus more efficient.

edited Jan 08 '16 at 12:50

answered Jan 08 '16 at 12:45

dbc

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Thank a lot for the help. Really appreciate this. Working just fine now :) – waris kantroo Jan 08 '16 at 13:08
Alternatively, you could do `qry.Take(1).Remove()` to remove the first occurrence. – Charles Mager Jan 08 '16 at 13:38

score 1 · Answer 2 · answered Jan 08 '16 at 12:50

UserId is not attribute in the XML. Its an element

XElement xEle = XElement.Load("input.xml");
        var qry = from element in xEle.Descendants()
                  where (string)element.Element("UserId") == "12345"
                  select element;
        if (qry.Count() > 0)
            qry.First().Remove();
        xEle.Save("input.xml");

And in your snippet you are comparing 12345 int with string type

Trying to delete an XML Node based on attribute value

2 Answers2