title: How does work SQL with order by 0?
body: <p>How does it work?</p>
  
  <pre><code>SELECT * 
  FROM table1
  ORDER BY 
  CASE WHEN field1 is not null 
      then 0
  end, 
  id DESC
  </code></pre>
  
  <p>I can replace 0 with other integer values but I still get correct result.</p>