title: Fatal error: Call to undefined function mysqli_connect
body: <p>My php script from PuTTY on a synology sever returns this:</p>
  
  <blockquote>
    <p>PHP Fatal error:  Call to undefined function mysqli_connect()`.</p>
  </blockquote>
  
  <p>Mysqli is installed on the server and has been used many times before in scripts via a browser. I don't understand why <code>mysqli_connect()</code> is supposedly undefined. How can I resolve this?</p>