Using Linq and XDocument, can I get all the child elements under parent tag?

Question

I have an XML

<data>
  <summary>
    <account curr_desc='USD' acct_nbr='123' net='1000.00' />
    <account curr_desc='USD' acct_nbr='456' net='2000.00' />
  </summary>
  <details>
    <accounts>
      <account acct_nbr="123" curr="USD">
        <activity color='False' settle_date='02 Jul 2010' amt='580.00' />
        <activity color='True' settle_date='09 Jul 2010' amt='420.00' />
      </account>
      <account acct_nbr="456" curr="USD">
        <activity color='True' settle_date='12 Dec 2010' amt='1500.00' />
        <activity color='True' settle_date='19 Dec 2010' amt='500.00' />
      </account>
    </accounts>
  </details>
</data>

Using Linq and XDocument, I can extract "summary" information but how can I extract "account" information under "summary" tag?

XDocument XMLDoc = XDocument.Load("testdata.xml");
XElement accounts = (from xml2 in XMLDoc.Descendants("summary")
                    select xml2).FirstOrDefault();

How can I specify something like "summary/account" so that it returns me all the elements under <summary>? Note, that I have <account> under <detail><accounts>, I only want the elements under summary tag.

Answer 1

You should use the Elements method:

var accounts = doc.Root.Elements("summary").Elements("account");

Or, alternatively, XPathSelectElements, which in this case is simpler:

var accounts = doc.XPathSelectElements("/data/summary/account");

In this instance you can also use Descendants, as Andrew Barber suggested, but in general you should only do this when you really want to find all descendants with a given name, and not just immediate children. Otherwise your code does a lot of searching that it doesn't need to, and may return elements you don't want it to.

Answer 2

var accountSummaryElems = 
   XMLDoc.Element("summary").Elements("account");

This gives you a collection of the account elements under the summary element. You can then iterate them to get the values.

EDITED to use the same pattern you were; I call First() instead of FirstOrDefault() because that code won't run anyway if the "account" element is not found.

Then you have the right idea with iterating over the collection returned.