title: mysql if not null, 0 or ""
body: <pre><code>SELECT * 
    FROM table WHERE id IN ('21') 
     AND (content_id IS NULL OR content_id = 0 OR content_id = '')
  </code></pre>
  
  <p>Is there a shorter way of writing this condition. </p>
  
  <p>I have a int() column that could be either: NULL, 0 or EMPTY. </p>