Setting session data from retrieved database data

[eluser]Unknown[/eluser]
As the title implies I'm trying to set session data from data in a users table in my database. My current method works, but It doesn't seem like it is the best solution. I was wondering if anyone had some suggestions to make the code a little more efficient.

Code:

if($query) { // If the users credentials validated
            $this->db->where('username', $this->input->post('username'));
            $users = $this->db->get('users')->result();
            
            foreach($users as $user) {
                $id = $user->id;
                $username = $user->username;
            }
            
            $data = array(
                'id' => $id,
                'username' => $username,
                'is_logged_in' => TRUE
            );
            
            $this->session->set_userdata($data);
                        redirect('ads');
}

Thanks.