There are many reasons you would want to restore a database from a backup file… But you should also test this on a test server just to make sure that your database backups are working correctly. Here’s the syntax:

mysql -h hostname -u username -pthepassword databasename < dumpfile.sql

Here’s an example:

mysql -h localhost -u root -p72aDufi8 db01 < thedumpfile.sql