public function read($sessionId)
    {
        $this->sessionExpired = false;

        $selectSql = $this->getSelectSql();
        $selectStmt = $this->db->query($selectSql)
                        ->bind(':id', $sessionId);

        $sessionRows = $selectStmt->row();

        if ($sessionRows) {
            if ($sessionRows->{$this->timeCol} + $sessionRows->{$this->lifetimeCol} < time()) {
                $this->sessionExpired = true;

                return '';
            }

            return is_resource($sessionRows->{$this->dataCol}) ? stream_get_contents($sessionRows->{$this->dataCol}) : $sessionRows->{$this->dataCol};
        }

        return '';
    }