title: order by sort wrong records
body: <p>I have a table with `Subscription' , when I sort recordes with order by I getting wrong result . My Result Does not sort , by MyColumn</p>
  
  <p>my query is :</p>
  
  <pre><code>Select Subscriptioncode from Subscription order by Subscriptioncode desc
  </code></pre>
  
  <p>my Result like as :</p>
  
  <pre><code>90
  80
  8
  700
  73
  634
  100
  </code></pre>
  
  <p>Why getting this Result ?</p>
  
  <blockquote>
    <p>In SubscriptionCode some Row is Null.</p>
  </blockquote>
  
  <p>100</p>