title: Using rails link_to with just an ID
body: <p>I have a page that needs a link to a User page with a given ID. So if the ID is 1234, I want the final href to be /user/1234.</p>
  
  <p>I tried to use </p>
  
  <pre><code>link_to "User", {:controller =&gt; "user", :action =&gt; "show", :id =&gt; 1234 } 
  </code></pre>
  
  <p>This gave me the URL</p>
  
  <pre><code>/assets?action=show&amp;controller=user&amp;id=1234
  </code></pre>
  
  <p>What should the link_to parameters be?</p>