If you want to keep backup of all of your MySQL Databases and don't want to take backup dumps one by one through some client or from terminal.
Here’s a quick handy solution for you.
Export all Databases
mysqldump -uroot -p --opt --all-databases > alldatabases.sql
Import all Databases
mysql -uroot -p < alldatabases.sql
See all of available options for mysqldump on their official website.