title: How to know that a rake task has been run in rails?
body: <p>I've a migration in my Rails app, that I'd like to run only if a particular rake task has been run, otherwise I'll lose a bunch of data. Following is something that I'd like to do:</p>
  
  <pre><code>if has_rake_task_been_run?
    remove_column :transactions, :paid_by
  end
  </code></pre>
  
  <p>Currently, I couldn't find anyway, instead of assuring this thing manually. Is there any work around for it?</p>