title: Checking for empty xml column
body: <p>Next query runs successfully:</p>
  
  <pre><code>select top(100) * from PackageSessionNodes 
  where Cast(ContentInteractions as nvarchar) != ''
  </code></pre>
  
  <p>Next gives me error
  Target string size is too small to represent the XML instance</p>
  
  <pre><code>update PackageSessionNodes set ContentInteractions = '&lt;contentinteractions /&gt;'
  where Cast(ContentInteractions as nvarchar) = ''
  </code></pre>
  
  <p>ContentInteractions is an xml column. No DDT defined on it.</p>
  
  <p>How can I solve the second query so that I get those records with '' as xml?</p>
  
  <p>I seems like SqlServer cannot deal with empty values that are stores in a xml column... but you can insert them... how's that?</p>