I ran into an issue today. I have a Blog model that has_many feed_entries.
In plain english, I needed a list of blogs ordered by most recently updated feed.
My models look like this:
blog.rb has_many :feed_entries feed_entry.rb belongs_to :blog
The query that makes it possible:
Blog.find(:all, :include => :feed_entries, :order => 'feed_entries.published_at DESC')
:include makes this possible!