You’ve messed up a migration. Now what?

Facepalm

You’ve written a migration in your Ruby on Rails application, and like any normal human, you’ve made a mistake!

In your development environment, you don’t want to drop and recreate the database you’re working in, you just want to ‘re-run’ the migration that you’ve now fixed.

No need to fear - I’ve got your back.

In your console, run:

rake db:migrate:status

Which will give you the following output:

database: my_database

 Status   Migration ID    Migration Name
--------------------------------------------------
   up     20170104131525  Devise create users
   up     20170104174145  Create roles
   up     20170704182740  Create fish
   up     20170704192840  Create octopus
   up     20170704195845  Create new attributes for fish and migrate from octopus

Nice. The latest one is the migration you want to ‘redo’, but this will work on any migration. Grab the migration id and run:

rake db:migrate:redo VERSION=20170704195845

That’s it! You’re ready to move on and didn’t need to spend a chunk of an hour resetting everything.