ruby on rails 3 - Problem saving data using Nested Attributes -

i'm

i'm building website on ruby on rails 3.0.7 , want save store object , languages. so, have following models:

class store < activerecord::base   belongs_to :user   has_many :languages, :through => :store_languages   has_many :store_languages    accepts_nested_attributes_for :store_languages    #validations   validates :title, :presence => true, :length => 5..100   validates :contact_email, :presence => true, :format => { :with => /^([^@\s]+)@((?:[-a-z0-9]+\.)+[a-z]{2,})$/i } end  class language < activerecord::base   has_many :stores, :through => :store_languages   has_many :store_languages end  class storelanguage < activerecord::base   belongs_to :store   belongs_to :language    validates :store_id, :presence => true   validates :language_id, :presence => true end 

storescontroller's relevant actions:

  def new     @store = store.new     @store.store_languages.build      respond_to |format|       format.html # new.html.erb       format.xml  { render :xml => @store }     end   end    # post /stores   # post /stores.xml   def create     #raise params.inspect     @store = current_user.stores.new(params[:store])      respond_to |format|       if @store.save         format.html { redirect_to(@store, :notice => 'store created.') }         format.xml  { render :xml => @store, :status => :created, :location => @store }       else         @store.store_languages.build         format.html { render :action => "new" }         format.xml  { render :xml => @store.errors, :status => :unprocessable_entity }       end     end   end 

view: /stores/new.html.erb:

<%= form_for(@store) |f| %>   <% if @store.errors.any? %>     <div id="error_explanation">       <h2><%= pluralize(@store.errors.count, "error") %> prohibited store being saved:</h2>        <ul>       <% @store.errors.full_messages.each |msg| %>         <li><%= msg %></li>       <% end %>       </ul>     </div>   <% end %>    <p>     <label for="title">title*</label><br />     <%= f.text_field :title %>   </p>    <p>     <label for="description">description</label><br />     <%= f.text_field :description %>   </p>    <p>     <label for="contact_email">contact e-mail*</label><br />     <%= f.text_field :contact_email %>   </p>    <p>     <label for="logo">logo</label><br />     <%= f.file_field :logo %>   </p>      <% f.fields_for :store_languages |lf| %>        <%= lf.collection_select :language_id, @languages, :id, :name, {}, {:multiple => true } %>     <% end %>    <div class="actions">     <%= f.submit %>   </div> <% end %> 

so, i've got following records in languages table:

 id |   name  3    english  4    español 

what happens when create new store selecting 2 languages list, save following @ store_languages table:

id | store_id | language_id 4 4 1

and language_id = 1 doesn't exist.

if debug application @ create action, following:

"store"=>{"title"=>"asdasdsdsadasdasdasd", "description"=>"", "contact_email"=>"asdasdsa@asdasdsad.com", "logo"=>"", "store_languages_attributes"=>{"0"=>{"language_id"=>["3", "4"]}}} 

you can see ids correct here: 3 , 4. so, don't know why saves 1.

any ideas?

try

  <%= lf.collection_select :language_ids, @languages, :id, :name, {}, {:multiple => true } %> 

(ie using ids instead of id in attribute name)