title: Source compiled php fatal PDO Exception; could not find driver
body: <p>I built Apache2.4, php 7.1.2, MySQL from source. All seem to work well, except When I try to connect to the database.
  I get "faral error: Uncaught PDOException: could not find driver in .....</p>
  
  <p>In php.ini config, all the extension line ends with .dll and none has .so, I have tried almost all suggestions from around but none seems to help. </p>
  
  <p>From what I learnt, I need php_mysql.so extension which I looked in my php extension folder <strong>/php/extensions/no-debug-zts-20160303/</strong> only to find <strong>opcahe</strong>.so</p>
  
  <p>I hope for one with this module to please share theirs with me or anyone with knowledge of how to fix it.
  I use Ubuntu 17</p>