How do I code a rake task that runs the Rails db:migrate task?

I would like to run db:migrate VERSION=0 and then db:migrate inside of my own rake task. I am confused about how to do this. Do I need a special require statement? My rake task will reside in the lib/tasks directory of a Rails app. Thanks.

From stackoverflow

• EDIT: Rake::Task[] won't accept parameters, you have to set it in ENV. In addition, you have to reenable the task to run it multiple times.

  ENV['VERSION']= '0'
  Rake::Task['db:migrate'].invoke
  Rake::Task['db:migrate'].reenable
  ENV.delete 'VERSION'
  Rake::Task["db:migrate"].invoke
  

  NOTE: Rake::Task.reenable requires Rake 0.8.2 or higher.

  fooledbyprimes : I tried this inside of my custom rake task (residing in lib/tasks) but it failed. ("rake aborted Don't know how to build task db:migrate VERSION=0")

• Check out rake db:reset as that will accomplish what you are trying to do.

  To see what all of your rake tasks do, run rake -T

  fooledbyprimes : This is interesting but it does not really explain how to run a pre-built rails task inside of a newly created custom rake task.

  erik : Yep, since Pesto got his answer in before mine, I figured it wouldn't hurt to show you an easier way even though it didn't answer the question exactly.

  fooledbyprimes : Actually Pesto's answer didn't work.

• Is your task just dependent on having a clean db? If that's the case then you can do:

  task :my_task => [:environment, 'db:reset']

  fooledbyprimes : Okay I like this. It works. This must surely mean that the :environment task loads all the rails rake namespaces.