title: Sequence contains more than one element - SingleOrDefault not helping
body: <p>I have the line below but still get an exception "<strong>Sequence contains more than one element</strong>"</p>
  
  <pre><code>Details rd = this.db.Details.SingleOrDefault(x =&gt; x.TId == Id &amp;&amp; x.TypeId == TypeId);
  </code></pre>
  
  <p>I was hoping that SingleOrDefault would avoid the exception.</p>