How to add a select without association to model? - ruby-on-rails-3

Question

I have a model called "Store" and it has an attribute "City" which has a "State" associated to it. I'm creating a store's filter by state and/or city with simple_form. The problem is, how to make simple_form does not associate the "State" to "Store" ?
class State < ActiveRecord::Base
attr_accessible :name
has_many :cities
end
class City < ActiveRecord::Base
attr_accessible :name
belongs_to :state
has_many :stores
end
class Store < ActiveRecord::Base
attr_accessible :latitude, :longitude, :description, :city_id
validates :city, :presence => true
validates :description, :presence => true, :length => {:maximum => 500}
validates :latitude, :presence => true
validates :longitude, :presence => true
belongs_to :city
end
<%= simple_form_for #store, :html => { :class => 'add-store-form', :style => "display:none;" } do |f| %>
<table border="0">
<tr>
<td>Estado:</td>
<td>
<%= f.collection_select :state, State.all, :include_blank => false, :label => false,
:input_html => { :id => "state_id", :name => "state_id" } %>
</td>
</tr>
.
.
This way is not working.
How can I do this?
Thanks in advance!

Answer 1

This is not the answer to you question, but improve your code by doing:
validates :city, :latitude, :longitude, :description, presence: true
validates :description, length: {maximum: 500}
And I recommend using Strong Parameters (Default in rails 4) to define with attributes can be assigned from forms instead of attr_accessible option