What happened to php_mysql.dll?
Thanks to the comment of Naruto I figured out that the dynamic loading of all the modules in the php\ext folder wasn't the culprit. Because the file php_mysql.dll wasn't in that folder, so it couldn't be loaded from there. After further analyses it seems that in the latest PHP (7.02) download for Windows 64-bit the php.ini file still contains this:
[PHP_MYSQL]extension=php_mysql.dllAfter commenting out the section the error in the log file was gone. As we obviously can't load that dll file anymore.
;[PHP_MYSQL];extension=php_mysql.dll
mysql extension was deprecated on v5.5 and removed on v7 please check out link below, https://wiki.php.net/rfc/remove_deprecated_functionality_in_php7
For PHP 7.2 when using PDO for MySQL I had to un-comment the following line:
;extension=pdo_mysql
extension=pdo_mysql
It's worth noting that there are other versions of the PDO extension also commented out:
;extension=pdo_firebird;extension=pdo_mysql;extension=pdo_oci;extension=pdo_odbc;extension=pdo_pgsql;extension=pdo_sqlite