mongodb - group by using mongoid in rails -
i using mongoid rails4, need group result supplying charts (statistics screen) using below code. @comments_stats = {} comments_data = comment.where(:created_at.lte => date.today-10.days).group_by {|d| d.created_at.to_date } comments_data.map{ |a| @comments_stats[a[0].strftime("%d-%m-%y")] = a[1].size} it give { "1-1-2014" => 2, "3-1-2014" => 1, "4-1-2014" => 2, "6-1-2014" => 4 } but want below { "1-1-2014" => 2, "2-1-2014" => 0, "3-1-2014" => 1, "4-1-2014" => 2, "5-1-2014" => 0, "6-1-2014" => 4 } any 1 suggest how simplify above query also. thanks prasad. you can try this: @comments_stats = {} last_date = date.today - 10.days comments_data = comment.where(:created_at.lte => last_date).group_by {|d| d.created_at.strftime("%d-%m-%y")} first_date = date.parse(comments_data.keys.min) (fi...