title: how to select the oldest or newest date using where?
body: <p>Is it possible to use a WHERE statement to find the oldest or the newest date ? 
  I mean something like </p>
  
  <pre><code>SELECT * 
  FROM employees 
  WHERE birth_date = MIN(birth_date);
  </code></pre>
  
  <p>I know this doesn't work, but I am asking if there is a syntax error or the whole idea is wrong. </p>