title: How do I add columns to devise after the initial create_table rake?
body: <p>I installed Devise, raked, and then realized afterwards, that I want to add :confirmable.</p>
  
  <p>Can I go back to the same initial migration and just uncomment out the helper that I want and then rake db:migrate again?</p>
  
  <p>I tried it and it didn't seem to work.  But I haven't seen an example of how to create a follow-on migration.</p>
  
  <p>Thanks!</p>
  
  <p>This is what I tried:</p>
  
  <pre><code>  1 class AddConfirmableToUsers &lt; ActiveRecord::Migration 
    2   def self.up 
    3     change_table :users do |t| 
    4       t.confirmable 
    5     end 
    6     add_index :users, :confirmation_token,   :unique =&gt; true  
    7   end 
    8    
    9   def self.down 
   10     remove_column :users, :confirmation_token 
   11   end 
   12   
   13 end 
  </code></pre>