Why are listings not saved in category?

Hello everyone,

I'm currently working on the functionality that users can create listings that are than saved in categories. I created tables and relationships but I cannot get the listings do be saved in the categories. Here is what I have:

Model category.rb

class Category < ActiveRecord::Base   has_many :listings end

model listing.rb class Listing < ActiveRecord::Base   belongs_to :user   belongs_to :category   default_scope -> { order('created_at DESC') }   validates :location, presence: true, length: { maximum: 20 }   validates :title, presence: true, length: { maximum: 20 }   validates :user_id, presence: true   validates :description, presence: true

end

Listings controller def new       @listing = Listing.new       @listings = Listing.paginate(page: params[:page])       @categories = Category.all     end

def create     @listing = current_user.listings.build(listing_params)     @categories = Category.all     if @listing.save       flash[:success] = "Job Post created"       redirect_to current_user       else         render 'listings/new'       end     end

Views categories/new <h1>New category</h1>

<%= render 'form' %>

<%= link_to 'Back', categories_path %>

Views categories/_form.html.erb <%= form_for(@category) do |f| %>   <% if @category.errors.any? %>     <div id="error_explanation">       <h2><%= pluralize(@category.errors.count, "error") %> prohibited this category from being saved:</h2>

      <ul>       <% @category.errors.full_messages.each do |message| %>         <li><%= message %></li>       <% end %>       </ul>     </div>   <% end %>

  <div class="field">     <%= f.label :name %><br>     <%= f.text_field :name %>   </div>   <div class="actions">     <%= f.submit %>   </div> <% end %>

Views Listing/new.html.erb

<div class="top"> <%= form_for(@listing) do |f| %> <%= render 'shared/error_messages', object: f.object %>

</div> <h1> Create Job Post </h1> <body> <div class=" form row">   <div class="span6 offset3 ">

    <%= f.label :title %>     <%= f.text_field :title %>

    <%= f.label :location %>     <%= f.text_field :location %>     <br>

      <%= f.text_area :description, placeholder: "Compose new listing...", class: "description_form" %> <br>   <p><b>Category:</b><br>

  <select name="listing[category_id]">    <% @categories.each do |category| %>        <option value="<%= category.id %>"          <%= ' selected' if category.id == @listing.category_id %>>          <%= category.name %>        </option>    <% end %>   </select></p>

</div>

<div class="space-button-form">   <%= f.submit "Post", class: "tfbutton tfbutton-search tfbutton-sign-up post" %> </div>

<% end %> </div> </div> </div>

I have a listings table with the following columns: id title description location user_id created_at updated_at category_id

and categories table id name created_at updated_at

When I create a new listing and than check the listings table, the category_id field is blank. Does anyone know why my listings are not saved in the categories?

Thank you very much