PG error for SELECT DISTINCT, ORDER BY expressions must appear in select list when trying to view on Heroku

I am getting this follow error after I added more relationships to my project. On localhost, the page displays perfectly fine. However, I get an error when trying to view it on heroku. ``` ActiveRecord::StatementInvalid (PG::Error: ERROR: for SELECT DISTINCT, ORDER BY expressions must appear in select list ``` Here is my traveldeal controller: ``` def show @traveldeal = @commentable = Traveldeal.find(params[:id]) @comments = Comment.all @title = @traveldeal.title @eventdeals = Eventdeal.tagged_with(@traveldeal.location_tag_list, :any => true, :order => 'RANDOM()', :limit => 3) end ``` traveldeal/show.html ``` <% unless @eventdeals.blank? %> <h1>Events in the area:</h1> <% @eventdeals.each do |eventdeal| %> <%= link_to eventdeal do %> <!-- content --> <% end %> <% end %> <% end %> ``` Heroku logs `SELECT DISTINCT eventdeals.* FROM "eventdeals" JOIN taggings event_taggings_e9f0e2e ON event_taggings_e9f0e2e.taggable_id = eventdeals.id AND event_taggings_e9f0e2e.taggable_type = 'Eventdeal' WHERE (event_taggings_e9f0e2e.tag_id = 1 OR event_taggings_e9f0e2e.tag_id = 3 OR event_taggings_e9f0e2e.tag_id = 4 OR event_taggings_e9f0e2e.tag_id = 5) ORDER BY RANDOM()):` This code was working so that I only displayed 3 random eventdeals that matched location (through act-as-taggable-on) with a traveldeal. However, after I added a relationship (related to eventdeals but not traveldeals), I started getting the pg error. Here are the relationships that was added: trip.rb ``` class Trip < ActiveRecord::Base has_many :eventdealtrips, :dependent => :destroy has_many :eventdeals, :through => :eventdealtrips end ``` eventdeal.rb ``` class Eventdeal < ActiveRecord::Base has_many :eventdealtrips has_many :trips, :through => :eventdealtrips, :dependent => :destroy end ``` eventdealtrip.rb ``` class Eventdealtrip < ActiveRecord::Base belongs_to :eventdeal belongs_to :trip end ``` Any advice on how I can still get a random array of 3 eventdeals? Thanks.