title: How can SCOPE_IDENTITY return null when @@IDENTITY does not?
body: <p>After executing an insert, I either select <code>SCOPE_IDENTITY</code> or <code>@@IDENTITY</code>.</p>
  
  <p><code>SCOPE_IDENTITY</code> returns null but <code>@@IDENTITY</code> does not. </p>
  
  <p>I don't understand how this is possible.</p>
  
  <p>Can you think of a reason why this happens?</p>