To Export a database, open up terminal, making sure that you are not logged into MySQL and type,
mysqldump -u [username] -p [database name] > [database name].sql
The database that you selected in the command will now be exported.
To import a database, first create a new blank database in the MySQL shell to serve as a destination for your data.
CREATE DATABASE newdatabase;
Then log out of the MySQL shell and type the following on the command line:
mysql -u [username] -p newdatabase < [database name].sql