rails中scaffold自动生成的CRUD,我怎样修改渲染的表单

<p><strong>目标：做一个博客系统，有两张表，分类(post_categories)和文章(posts).想保持rails的scaffold，尽量减少代码编写,来完成CRUD功能。</strong></p>
<p><strong>1。数据库表：</strong></p>
<p><font color="#993300"><font color="#000000">\db\migrate\002_create_post_categories.rb</font><br />
create_table :<strong>post_categories</strong> do |t|<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.column :name, :string, :null =&gt;false</font></p>
<p><font color="#993300"><font color="#000000">\db\migrate\002_create_post.rb</font><br />
create_table :<strong>posts</strong> do |t|<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.column :category_id,&nbsp;&nbsp; :integer, :null =&gt;false<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.column :title, :string<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.column :doc,&nbsp;&nbsp; :text<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.column :addTime,&nbsp;&nbsp; :datetime, :default =&gt;'0000-00-00 00:00:00'<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.column :isOpen, :boolean, :default =&gt;true<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; t.column :acount,&nbsp;&nbsp; :int, :default =&gt;1<br />
&nbsp;&nbsp;&nbsp;&nbsp; end<br />
&nbsp;&nbsp;&nbsp;&nbsp; execute &quot;alter table posts add constraint fk_post_category&nbsp;&nbsp; foreign key (category_id) <br />
&nbsp;&nbsp;&nbsp;&nbsp; references post_categories(id)&quot;</font></p>
<p><strong>2.用generate生成Models和Controllers</strong></p>
<p><strong>3.用generate生成views:</strong></p>
<p>generate:scaffold<br />
model name: post<br />
controller name:post<br />
actions:post</p>
<p>默认情况下，我们看到：\app\views\post\new.rhtml<br />
<font color="#993300">&lt;% form_tag :action =&gt; 'create' do %&gt;<br />
&nbsp;&nbsp; &lt;%= render :partial =&gt; 'form' %&gt;<br />
&nbsp;&nbsp; &lt;%= submit_tag &quot;Create&quot; %&gt;<br />
&lt;% end %&gt;</font></p>
<p>但因为posts外键连接了表post_categories,而以上的表单没有指定category_id字段，所以操作是不成功的。现在做以下修改：<br />
\app\controllers\post_controller.rb<br />
<font color="#993300" size="2">def new<br />
&nbsp;&nbsp;&nbsp;&nbsp; @post = Post.new<br />
&nbsp;&nbsp;&nbsp;&nbsp; @post_categories=PostCategory.find(:all)<br />
&nbsp;&nbsp; end</font><br />
即在原来默认的基础上，增加了@post_categories=PostCategory.find(:all)<br />
然后修改页面：\app\views\post\new.rhtml<br />
<font color="#993300">&lt;% form_tag :action =&gt; 'create' do %&gt;<br />
&nbsp;&nbsp; &lt;%= render :partial =&gt; 'form' %&gt;<br />
&lt;select name=&quot;post[category_id]&quot;&gt;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;% @post_categories.each do |c| %&gt;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;option value=&quot;&lt;%=c.id%&gt;&quot;&gt;&lt;%=c.name%&gt;&lt;/option&gt;<br />
&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; &lt;% end %&gt;<br />
&nbsp;&nbsp; &lt;/select&gt;<br />
&nbsp;&nbsp; &lt;%= submit_tag &quot;Create&quot; %&gt;<br />
&lt;% end %&gt;</font></p>
<p>这样，程序运行成功，可以添加文章了。<br />
不过问题又来了，因为posts表单是默认渲染的，在添加文章的时候显示了标示文章浏览次数的字段acount.而这个字段是不要求用户输入的，我们需要在添加文章的时候隐藏这个字段，怎么办？</p>
<p>怎么办。。。<br />
</p>