title: Update db/migrate after manually updating models?
body: <p>For example i have this model:</p>
  
  <pre><code>class Product &lt; ActiveRecord::Base
    attr_accessible :name, :order
  end
  </code></pre>
  
  <p>Then when i did <code>rake db:migrate</code> it created this <strong>db/migrate/20120825132038_create_products.rb</strong>:</p>
  
  <pre><code>class CreateProducts &lt; ActiveRecord::Migration
    def change
      create_table :products do |t|
        t.integer :order
        t.string :name
  
        t.timestamps
      end
    end
  end
  </code></pre>
  
  <p>But it all happend cuz i used <code>rails generate Product order:integer name:string</code></p>
  
  <p>Now after i go to Product model and changes it manually to:</p>
  
  <pre><code>class Product &lt; ActiveRecord::Base
    attr_accessible :name, :order, :category_id
  
    validates :name, uniqueness: true
    belongs_to :category
  end
  </code></pre>
  
  <p>How can i auto update the <strong>db/migrate/20120825132038_create_products.rb</strong> with the updates?</p>