title: Heroku - ActionView::Template::Error (PG::Error: ERROR: column category_products.desc does not exist
body: <p>I am using RailsAdmin and this is the error I get when I click on my model <code>CategoryProduct</code> within RailsAdmin.</p>
  
  <p>This is what the error looks like:</p>
  
  <pre><code>Started GET "/admin/category_product" for 67.230.41.62 at 2012-12-21 23:20:07 +0000
  2012-12-21T23:20:07+00:00 app[web.1]: 
  2012-12-21T23:20:07+00:00 app[web.1]: ActionView::Template::Error (PG::Error: ERROR:  column category_products.desc does not exist
  2012-12-21T23:20:07+00:00 app[web.1]: LINE 1: ...ry_products".* FROM "category_products"  ORDER BY category_p...
  2012-12-21T23:20:07+00:00 app[web.1]:                                                              ^
  2012-12-21T23:20:07+00:00 app[web.1]: : SELECT  "category_products".* FROM "category_products"  ORDER BY category_products. desc LIMIT 20 OFFSET 0):
  2012-12-21T23:20:07+00:00 app[web.1]:     120:       %tbody
  2012-12-21T23:20:07+00:00 app[web.1]:     121:         - @objects.each do |object|
  2012-12-21T23:20:07+00:00 app[web.1]:     122:           %tr
  2012-12-21T23:20:07+00:00 app[web.1]:     123:             %td
  2012-12-21T23:20:07+00:00 app[web.1]:     124:               = check_box_tag "bulk_ids[]", object.id, false
  2012-12-21T23:20:07+00:00 app[web.1]:     125:             - if @other_left_link ||= other_left &amp;&amp; index_path(params.except('set').merge(params[:set].to_i != 1 ? {:set =&gt; (params[:set].to_i - 1)} : {}))
  2012-12-21T23:20:07+00:00 app[web.1]:     126:               %td.other.left= link_to "...", @other_left_link, :class =&gt; 'pjax'^
  </code></pre>
  
  <p>These are my <code>category</code>, <code>product</code> &amp; <code>category_product</code> models:</p>
  
  <p><code>Category.rb</code></p>
  
  <pre><code># == Schema Information
  #
  # Table name: categories
  #
  #  id         :integer          not null, primary key
  #  name       :string(255)
  #  created_at :datetime         not null
  #  updated_at :datetime         not null
  #
  
  class Category &lt; ActiveRecord::Base
    attr_accessible :name
      has_many :category_products do
           def with_products
             includes(:product)
           end
         end
  
    has_many :products, :through =&gt; :category_products
  
    def top_products(number)
      category_products.with_products.order("purchases_count DESC").limit(number).map {|c| c.product} # product included
    end
  
  end
  </code></pre>
  
  <p><code>Product.rb</code></p>
  
  <pre><code># == Schema Information
  #
  # Table name: products
  #
  #  id          :integer          not null, primary key
  #  name        :string(255)
  #  description :string(255)
  #  price       :float
  #  vendor_id   :integer
  #  created_at  :datetime         not null
  #  updated_at  :datetime         not null
  #  image       :string(255)
  #
  
  class Product &lt; ActiveRecord::Base
    attr_accessible :name, :description, :price, :vendor_id, :image, :category_ids
      mount_uploader :image, ImageUploader
  
      belongs_to :vendor
      has_many :category_products do
             def with_categories
               includes(:category)
             end
      end
  
      has_many :categories, :through =&gt; :category_products
  
    def top_categories(number)
      category_products.with_categories.order("purchases_count DESC").limit(number).map {|c| c.category} # category included
    end
  
  end
  </code></pre>
  
  <p><code>Category_Product</code></p>
  
  <pre><code># == Schema Information
  #
  # Table name: category_products
  #
  #  id              :integer          not null, primary key
  #  product_id      :integer
  #  category_id     :integer
  #  purchases_count :integer          default(0)
  #  created_at      :datetime         not null
  #  updated_at      :datetime         not null
  #
  
  class CategoryProduct &lt; ActiveRecord::Base
    attr_accessible :product_id, :category_id, :purchases_count
  
      belongs_to :product
    belongs_to :category
  
    validates_uniqueness_of :product_id, :scope =&gt; :category_id
  end
  </code></pre>
  
  <p>Any ideas what may be causing this?</p>
  
  <p>Thanks.</p>