title: CodeIgniter session not saved
body: <p>I have controller example name by test.</p>
  
  <p>In index method I will make session, it will store in database successfully, but when I want to read them in other method, it will make another session in database.
  For example:</p>
  
  <pre><code>public function index(){
       $this-&gt;session-&gt;set_userdata('test','test');
  }
  public function test(){
       echo $this-&gt;session-&gt;userdata('test');
  }
  </code></pre>
  
  <p>It will echo nothing. And when I check the database, it made new row.</p>