You can restore a database through the phpmyadmin interface, provided that you have a backup and the sql file is under 7mb. If you have the backup file, but it’s bigger than 7mb you’ll have to use shell to accomplish it. There’s an article in the wiki titled somethign like migrating mysql that will cover ‘importing’ your database.
Don’t have a backup of your database? You should always keep backups, but if not support should have a copy they can restore for you. Just put in a support ticket and be as specific as you can for the timeline of the restore point. (I head that if you’ve deleted the database from the panel, support won’t have any backups of it)