How Can I Copy Values From One Table To Another By Clicking On A Button

public function ifMailExists($user_id,$user_email) {
    $selqry = "SELECT users.*, a.contact_id as contact_id, b.contact_emails as contact_emails FROM users
                    INNER JOIN contacts a ON a.contact_id = users.user_id
                    INNER JOIN contacts b ON b.contact_email = users.user_email
                        WHERE  (user_id = '" . $user_id . "' AND user_email = '" . $user_email . "')
                        OR (user_id = '" . $user_id . "' AND user_email = '" . $user_email . "')";
        $query = $this->db->query ( $selqry );
        return $query;

    }