显示session信息

在控制器中添加了几行代码以显示当前session信息，将session信息中的部分内容存入websites数据库中的ci_sessions表中。视图文件不变。

其中，session中的last_activity内容不知道到哪里去查？已经发帖到社区求助！

start.php内容为：

<?php
class Start extends CI_Controller
{
function __construct()
{
  parent::__construct();
  $this->load->helper('url');
  $this->load->helper('form');
  $this->load->library('unit_test');
  $this->unit->active(TRUE);
  $this->load->database();
 }

 function index()
 {
 // $data['mytitle']="My site";
 // $data['base']=$this->config->item('base_url');
 // $data['css']=$this->config->item('css');
  $data['mytitle']="A website to monitor other websites";
  $data['text']="Please log in here!";

  $this->load->view('entrypage',$data);
 }

 function assessme()
 { 
  $this->load->library('session');
  $name=$_POST['username'];
  $password=$_POST['password'];
  if($name=='fred' && $password=='12345')
  {
   $newdata=array('status'=>'ok');
   $this->session->set_userdata($newdata);
   echo $this->session->userdata('ip_address')."<br>";
   echo $this->session->userdata('session_id')."<br>";
   echo $this->session->userdata('user_agent')."<br>";
   echo $this->session->userdata('last_activity')."<br><br>";

   $currentsession=array('ip_address'=>$this->session->userdata('ip_address'),
           'session_id'=>$this->session->userdata('session_id'),
           'user_agent'=>$this->session->userdata('user_agent'),
           'last_activity'=>$this->session->userdata('last_activity'));
   $this->db->insert('ci_sessions',$currentsession);

   $this->mainpage();
  }
  else
  { 
   $this->index();
  ;}
 }

 function mainpage()
 {
  $test=floor(1.56);
  $expected_result=1;
  $test_name='test php floor function';
  $this->unit->run($test,$expected_result,$test_name);
  $test=floor(2.56);
  $expected_result=1;
  $test_name='tests php floor function';
  $this->unit->run($test,$expected_result,$test_name);
  //echo $this->unit->result();
  $this->load->view('mainpage');
 }
}
?>