Collection_Select，我需要在创建控制器中更改什么？

Question

我创建了2个模型：

class Fixture < ActiveRecord::Base
attr_accessible :away_score, :away_team_id, :home_score, :home_team_id, :result, :week
belongs_to :home_team, :class_name => Team
belongs_to :away_team, :class_name => Team
end

class Team < ActiveRecord::Base
attr_accessible :form, :name
has_many :fixtures, :class_name => Fixture, :foreign_key => :home_team_id
has_many :fixtures, :class_name => Fixture, :foreign_key => :away_team_id
end

然后我在我的灯具表单中完成了一个collection_select，它允许我获取团队列表，但是当我尝试创建一个灯具时，它不会更新我的灯具表中的away_team_id和home_team_id，我相信我需要在我的fixtures控制器创建方法中添加一些代码，但不确定我需要添加什么？

<%= form_for(@fixture) do |f| %>
<% if @fixture.errors.any? %>
<div id="error_explanation">


  <h2><%= pluralize(@fixture.errors.count, "error") %> prohibited this fixture from      being saved:</h2>

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

  <div class="field">
    <%= f.label :week %><br />
    <%= f.text_field :week %>
  </div>
  <div class="field">
    <%= f.label :home_team_id %><br />
    <%= collection_select(:team, :home_team_id, Team.all,:id,:name,:prompt => 'Please select a team')  %>
  </div>
  <div class="field">
    <%= f.label :away_team_id %><br />
    <%= collection_select(:team, :away_team_id, Team.all,:id,:name,:prompt => 'Please select a team')  %>
  </div>
  <div class="field">
    <%= f.label :home_score %><br />
    <%= f.number_field :home_score %>
  </div>
  <div class="field">
    <%= f.label :away_score %><br />
    <%= f.number_field :away_score %>
  </div>
  <div class="field">
    <%= f.label :result %><br />
    <%= f.text_field :result %>
  </div>
  <div class="actions">
    <%= f.submit %>
  </div>

<% end %>