How do I translate the following to simple form?

<%= form_for(@bill) do |f| %>

<%= f.label :location_id %>
<%= f.collection_select(:location_id, @locations, :id, :location_name, 
      {:selected => @bill.location_id}) %>

I can't use a simple association because @locations is the result of a where query.

ruby-on-rails simple-form
Edit
Report