mysql -u root -p  databasename< file.sql

Backup a MySQL database to a file:

mysqldump -u root -p databasename > file.sql

Creating a new user and database in MySQL:

First, load up the mysql client:

mysql -u root -p

Create the database:

CREATE DATABASE databasename;

Create the user:

GRANT ALL PRIVILEGES ON databasename.* TO "databaseuser"@"hostname" IDENTIFIED BY "password";

All done, clean up and exit:

FLUSH PRIVILEGES;
EXIT;