More Complex Join with Rails/ActiveRecord

[Mauricio_Linhares1 (Maurício Linhares)]

Just a quick try (you haven't showed up your database schema):

@articles = Article.all( :conditions => ["start_date >= ? AND id NOT IN ( SELECT m.article_id from moderations m WHERE m.user_id = ? )", today, current_user.id], :order => 'start_date')