many_to_many :liked_articles, :class => :Article, :join_table => :article_votes, :right_key => :article_id do |ds|
    ds.filter(:choice == 'likes')
  end
 
SELECT `articles`.* FROM `articles` INNER JOIN `article_votes` ON ((`article_votes`.`article_id` = `articles`.`id`) AND (`article_votes`.`user_id` = 1)) WHERE 0