Using Join Table on Code Igniter

simple-qury.php

//on model
function getUserDetails(){

        $this->db->select('coment,name,dob,contry,main_photo');
        $this->db->from('user');
        $this->db->join('coment', 'coment.email = user.email');
        $query = $this->db->get();
        if ($query->num_rows() > 0) {
            return $query->result();
        }
        else {
            return null;
        }
}

//on controller

function getUserDetails(){
$query = $this->mymodel->getUserDetails();
print_r($query);

}