Codeigniter session value access - mysql

Question

I recently bought project management system, I was trying to add new forms but my forms are not working. I think my problem is the model, I am failing to get a session value (project_code) submitted to the database to make sure that the specific entry is visible to the specific project. The system I bought is ekushey available on codecanyon.
Model
function client_invoicing_add($project_code = '') {
//$data['project_code'] = $project_code;
//$data['project_code'] = $this->session->userdata('project_code');
$data['client_payment_milestone'] = $this->input->post('client_payment_milestone');
$data['client_payment_deliverables'] = $this->input->post('client_payment_deliverables');
$data['client_payment_date'] = $this->input->post('client_payment_date');
$data['client_payment_amount'] = $this->input->post('client_payment_amount');
$data['timestamp'] = strtotime($this->input->post('timestamp'));
$data['client_id'] = $this->session->userdata('login_user_id');
$data['project_code'] = $this->db->get_where('project' , array('project_id' => $project_id))->row()->project_code;
//$data['project_id'] = $this->db->get_where('project' , array('project_code' => $project_code))->row()->project_id;
$this->db->insert('client_invoicing' , $data);
}
Controller
// Client invoicing
function client_invoicing($param1 = '' , $param2 = '' , $param3 = '') {
if ($this->session->userdata('client_login') != 1) {
$this->session->set_userdata('last_page', current_url());
redirect(base_url(), 'refresh');
}
if ($param1 == 'add') {
$this->crud_model->client_invoicing_add($param2); // param2 = project code
}
if ($param1 == 'edit') {
$this->crud_model->client_invoicing_edit($param2); // param2 = client payment id
}
if ($param1 == 'delete') {
$this->crud_model->client_invoicing_delete($param2); // param2 = client payment id
}
}

Answer 1

you can use var_dump($this->session->all_userdata()); to print all session objects. and from them you can check if session is already set or not.

Answer 2

Session array is available through the $_SESSION global:
$name = $_SESSION['name'];
// or:
$name = $this->session->name
// or:
$name = $this->session->userdata('name');
If you want to retrieve all of the existing userdata
$_SESSION
// or:
$this->session->userdata();
Note : The userdata() method returns NULL if the item you are trying
to access does not exist.