When you are working with a complicated database structure, and find yourself needing to debug a complex or dangerous (delete) action, you might be hesitant to experiment. Keep experimenting! Don’t want to setup all that data again? No worries. You can use a sandbox
$ rails c -s
Usage: rails console [environment] [options] -s, --sandbox Rollback database modifications on exit.
The sandbox flag will keep all database changes in a database transaction when you start the rails console and automatically issue a rollback when you quit the console.