cannot log in to the mysql server (wamp and wordpress)

The default Wamp user`s credentials are:

username: root
password: (empty, nothing, nada)

If you already have a WordPress website previously created on your Wamp system, then go to /www/yourlocalsite/wp-config.php and check out the username and password you set. Here`s an example:

/** MySQL database username */
define('DB_USER', 'root');

/** MySQL database password */
define('DB_PASSWORD', '');

/** MySQL hostname */
define('DB_HOST', 'localhost');

Thanks!