MySQL у меня есть, и PDO есть.
Но команда
bool extension_loaded ( 'mysql' )
выдаёт false.
$ php -m | grep sql
mysqli
mysqlnd
pdo_mysql
pdo_pgsql
pdo_sqlite
pgsql
sqlite3
$ php -v
PHP 7.0.8-0ubuntu0.16.04.3 (cli) ( NTS )
Copyright (c) 1997-2016 The PHP Group
Zend Engine v3.0.0, Copyright (c) 1998-2016 Zend Technologies
with Zend OPcache v7.0.8-0ubuntu0.16.04.3, Copyright (c) 1999-2016, by Zend Technologies
with Xdebug v2.4.0, Copyright (c) 2002-2016, by Derick Rethans