<% for city in @rooms.map(&:city).uniq.sort %> <option value="<%= city %>"><%= city %></option> <% end %>
or even: Parked at Loopia
<%= options_for_select(@rooms.map(&:city).uniq.sort) %>
If you needed the value to be the city_id rather than the city (name), you could:
<%= options_for_select(@rooms.map { |r| [ r.city, r.city_id ] }.uniq.sort) %>
(Of course, this begins to be a bad example as it doesn't sound like Room belongs_to :city anyway.)
-Rob
Rob Biedenharn http://agileconsultingllc.com Rob@AgileConsultingLLC.com Skype: rob.biedenharn
