Php 登录到codeigniter错误

我是新的codeigniter我做了一个登录页面，但它不工作。 我想要一个使用会话的代码。我需要启动会话（）；在每个控制器中，或者在codeigniter中有一种方法，它将自动在所有控制器中？（我应该那样做吗？）

模型

---

使用此

$this->session->userdata（'logged_in'）

而不是

$this->session->userdata['logged_in']

希望它有帮助

您不需要启动会话（）；在每个控制器中。加载会话库就足够了$此->加载->库（“会话”）；这是另一个打开用户指南并逐步检查所有内容的案例，即调试…我设法纠正了问题，但出现了另一个问题，即当我使用“=”作为用户名和密码时，它直接进入adminpanel，而无需任何检查。如何使用mysql真实转义字符串

function __construct()   // controller
{
    parent::__construct();
    $this->load->library('session');
    $this->load->database();
    $this->load->helper('url');
    $this->load->library('form_validation');
    $this->load->helper('form');
    $this->load->model('np_login_model');
}

public function index()
{
    $this->load->view('admin/login/login_dashboard');

}

// Check for user login process
public function user_login_process()
{

    $this->form_validation->set_rules('username', 'Username', 'trim|required|xss_clean');
    $this->form_validation->set_rules('password', 'Password', 'trim|required|xss_clean');
if ($this->form_validation->run() == FALSE)
{
    if(isset($this->session->userdata['logged_in']))
    {
        $this->load->view('admin/intropage');
    }
    else
    {
        $this->load->view('admin/login/login_dashboard');
    }
} 
else
{
    $data = array('username' => $this->input->post('username'),'password' => $this->input->post('password'));
    $result = $this->np_login_model->login($data);
    if ($result == TRUE)
    {
        $username = $this->input->post('username');
        $result = $this->np_login_model->read_user_information($username);
        if ($result != false) 
        {
        $session_data = array('username' => $result[0]->user_name);
        // Add user data in session
        $this->session->set_userdata('logged_in', $session_data);
        $this->load->view('admin/intropage');
        }
    } 
    else
    {
    $data = array('error_message' => 'Invalid Username or Password');
    $this->load->view('admin/login/login_dashboard', $data);
    }
}
} 

public function login($data) 
{
    $condition = "user_name =" . "'" . $data['username'] . "' AND " . "user_password =" . "'" . $data['password'] . "'";
    $this->db->select('*');
    $this->db->from('np_login');
    $this->db->where($condition);
    $this->db->limit(1);
    $query = $this->db->get();

    if ($query->num_rows() == 1)
    {
        return true;
    } 
    else
    {
        return false;
    }
}

// Read data from database to show data in admin page
public function read_user_information($username) {

$condition = "user_name =" . "'" . $username . "'";
$this->db->select('*');
$this->db->from('np_login');
$this->db->where($condition);
$this->db->limit(1);
$query = $this->db->get();

if ($query->num_rows() == 1) {
return $query->result();
} else {
return false;
}
}