title: MySQL: select first element of a comma-separated list
body: <p>Unfortunately, I have a field column which contains values like</p>
  
  <ul>
  <li>4</li>
  <li>12,3</li>
  <li>8,5,6,7</li>
  </ul>
  
  <p>I'm going to write a SELECT statement, whose result would be:</p>
  
  <ul>
  <li>4</li>
  <li>12</li>
  <li>8 </li>
  </ul>
  
  <p>How can I do it in practice, since MySQL does not provide a "split" function?</p>