If your MySQL user has a password:

mysql -h localhost -u [MySQL user, e.g. root] -p[database password] [name of the database] < [name of your sql dump, e.g. sqldump.sql]

Please note:  there's no space between -p and the password!

If there's no password:

mysql -h localhost -u [MySQL user, e.g. root] [name of the database] < [name of your sql dump, e.g. sqldump.sql]