I did the same thing once by accident and thankfully only lost 1 hour of data. The single lowest point of my career and thinking about the details of that day makes my stomach sink even now as I type this.

I ran a rake db schema dump command of some kind and instead of it returning the schema of the database, it decided to just completely nuke my entire database. Instantly. It's very easy to fuck up so cover your ass gents, and backup often and run your restores periodically to make you can actually do them in case of an emergency.