[peter]

You can use MySQL's GRANT command:

GRANT ALL PRIVILEGES ON test_db.* TO 'test_db_user'@'localhost';
GRANT ALL PRIVILEGES ON test_db.* TO 'test_db_user'@'%';
GRANT ALL PRIVILEGES ON test_db.* TO 'test_db_user'@'localhost' IDENTIFIED BY 'password';
GRANT ALL PRIVILEGES ON test_db.* TO 'test_db_user'@'%' IDENTIFIED BY 'password';

You can find details about it here: http://dev.mysql.com/doc/mysql/en/grant.html

Peter