in This Tutorial you will Learn " Change MySQL Default Port and Listening Address"
By default, MySQL and MariaDB listen on port 3306 on the loopback address. It is a good idea to change the MySQL default port for security purposes.
lsb_release -d ; hostname -I ; mysql -V
MySQL - nano /etc/mysql/mysql.conf.d/mysqld.cnf
netstat -tln
bind-address = 127.0.0.1
Port = 9090
systemctl restart mysql
MariaDB - nano /etc/mysql/mariadb.conf.d/50-server.cnf
netstat -tln
bind-address = 127.0.0.1
Port = 9090
systemctl restart mariadb
Code -