public function tableNames()
    {
        if ($this->databaseType === 'mysql') {
            $sql = "SHOW TABLES";
        } elseif ($this->databaseType === 'sqlite') {
            $sql = "SELECT name FROM sqlite_master WHERE type='table'";
        } else {
            throw new \RuntimeException("Unsupported database type: '{$this->databaseType}'");
        }
        $stm = $this->query($sql);
        $r = $stm->fetchAll();

        $tables = array_map(function ($t) {
                return reset($t);
            }, $r);
        
        $this->logQuery($sql);

        return $tables;
    }