title: How to get URL parameters in Rails?
body: <p>When a POST request is processed, params[:id] returns the value of "id" stored in the form that was posted.</p>
  
  <p>However I want to get the value stored in the url (query string).</p>
  
  <pre><code>def some_action
    id = params[:id] # Gets id from here: /some_action?id=[VALUE] only when request.post? is false
    if request.post?
    # Do some stuff, can't get the id value from the url
    ...
  end
  </code></pre>
  
  <p>So how to get the value from the URL in a POST request?</p>