[RUBY] First post. What happened while creating the group function

Routing Error About Routing Error that occurred while creating the group function In this image, the controller is groups. In the image below, it is groups, but by setting it to groups here, a Routing Error occurred.

About migration

For example, when you make a mistake in the migration file with db: migrate like this You can correct it by using db: rollback. Also, the correction is completed with db: migrate.

db:rollback With db: rollback, you can only go back one step.

db: rollback STEP = numbers

db: rollback STEP = You can go back to any place by using numbers.