title: How do I filter DataRows on a list of values?
body: <p>I have a collection of DataRow's that have a column TransactionID - I'm trying to filter out the DataRow's that don't have a matching value in a list of TransactionID's</p>
  
  <pre><code>List&lt;int?&gt; IDs = _sqlResultsRaw.AsEnumerable()
              .Select(x =&gt; x.Field&lt;int?&gt;("TransactionID")).ToList();
  List&lt;int?&gt; pIDs = _sqlResultsRaw.AsEnumerable()
              .Select(x =&gt; x.Field&lt;int?&gt;("ParentTransactionID")).ToList();
  
  List&lt;int?&gt; IDsToKeep = IDs.Except(pIDs).ToList();
  </code></pre>
  
  <p>I want to create a collection of DataRows that have a matching value from IDsToKeep. If the TransactionID isn't in IDsToKeep, I want to remove it</p>