title: Modification to mySQL query to show empty rows at the end, not at the top while using ASC
body: <p>In my mysql table the column <code>contact</code> is either empty or it has a date.</p>
  
  <pre><code>$sql = "SELECT * FROM cars WHERE eidos='AETOS' order by  contact asc"; 
  </code></pre>
  
  <p>My goal is to show the closer <code>contact</code> dates at the top.</p>
  
  <p>For now, it shows me all the rows that have no date at the top, and at the end those rows that have a <code>contact</code> date are shown ascending, the smaller date at the top.</p>
  
  <p>How to show at the top the rows that have <code>contact</code> date in ascending, followed by the empty rows?</p>