Maybe. Maybe not.
The error message will go away, but anything you've installed and configured in the admin previously will no longer be there. Thus, any addons you've added will need to be re-added again.

If the only thing you've changed is stylesheets and php templates for your own template, then you might be able to get away with that strategy. However, ALL the settings you changed in the admin area were stored in the database. So, since you deleted your database, all that information is lost.

Time to get in the habit of making regular backups.