public function buildCache($table = null, $key = null, $cache = null)
    {
        if ($this->sql &&
            ($table === null || $this->setTableName($table)) &&
            ($key === null || $this->setKeyName($key)) &&
            ($cache === null || $this->setCacheName($cache))) {
            if ($this->sql->query("
                CREATE TABLE IF NOT EXISTS `{$this->table}` (
                    `id` int(11) unsigned NOT NULL AUTO_INCREMENT,
                    `{$this->key}` text NOT NULL,
                    `{$this->cache}` longtext NOT NULL,
                    `expire` timestamp NULL DEFAULT NULL,
                    `timestamp` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
                    PRIMARY KEY (`id`)
                );
            ")) {
                $this->initialized = true;

                /* Upgrade older cache tables for longer cache data */
                $this->sql->query("
                    ALTER TABLE `{$this->table}` CHANGE `{$this->cache}` `{$this->cache}` longtext NOT NULL;
                ");

                /* Upgrade older cached tables to include an expire column for each row */
                $this->sql->query("
                    ALTER TABLE `{$this->table}` ADD `expire` timestamp NULL DEFAULT NULL AFTER `{$this->cache};
                ");
            }
        }
        return $this->initialized;
    }