title: What is the difference between "Is Not Null" and "Not Is Null"
body: <pre><code>SELECT id FROM customers WHERE type IS NOT Null;
  </code></pre>
  
  <p>Versus:</p>
  
  <pre><code>SELECT id FROM customers WHERE NOT type IS NULL;
  </code></pre>
  
  <p>The data that either of the above will return will be exactly the same.</p>
  
  <p>What is the difference and why would one of them be preferable?</p>
  
  <p><strong>Edit:</strong><br>
  It seems to me that there might be a difference when it comes to performance. Anyone care to elaborate on this?</p>