Rails - Jul 2009 - How to build scope for count() & has many polymorphic?

Hello, i have the following models in my application:

class Message < ActiveRecord::Base
  has_many :comments, :as => :commentable, :dependent => :destroy,
:order => ''created_at ASC''
end

class Comment < ActiveRecord::Base
  belongs_to :commentable, :polymorphic => true
end

I need "commented" named scope, which do the follownig thing:

Message.commented -> returns all messages where comments is > 0.

How i can do this?
-- 
Posted via http://www.ruby-forum.com/.

anybody knows?
-- 
Posted via http://www.ruby-forum.com/.

The typical way around this is to turn on counter caching
for :comments, and filter against that.

--Matt Jones

On Jul 22, 8:18 am, Joao Silva
<rails-mailing-l...-ARtvInVfO7ksV2N9l4h3zg@public.gmane.org>
wrote:
> Hello, i have the following models in my application:
>
> class Message < ActiveRecord::Base
>   has_many :comments, :as => :commentable, :dependent => :destroy,
> :order => ''created_at ASC''
> end
>
> class Comment < ActiveRecord::Base
>   belongs_to :commentable, :polymorphic => true
> end
>
> I need "commented" named scope, which do the follownig thing:
>
> Message.commented -> returns all messages where comments is > 0.
>
> How i can do this?
> --
> Posted viahttp://www.ruby-forum.com/.