[I found this](http://quotedprintable.com/2007/6/29/rake-db-rollback) awesome trick to rollback a Rails database migration one step. Add the following code to Rakefile.
```ruby
namespace :db do
desc 'Rolls the schema back to the previous version. Specify the number of steps with STEP=n'
task :rollback => :environment do
step = ENV['STEP'] ? ENV['STEP'].to_i : 1
version = ActiveRecord::Migrator.current_version - step
ActiveRecord::Migrator.migrate('db/migrate/', version)
end
end
```
And roll back with a breeze.
```ruby
rake db:migrate
rake db:rollback
```