public function addEnableCommentsField()
    {
        Cache::clear(false, '_cake_model_');

        foreach (['Pages', 'Posts'] as $table) {
            $Table = $this->loadModel('MeCms.' . $table);

            if (!$Table->getSchema()->hasColumn('enable_comments')) {
                $Table->getConnection()->execute(sprintf('ALTER TABLE `%s` ADD `enable_comments` BOOLEAN NOT NULL DEFAULT TRUE AFTER `preview`', $Table->getTable()));
            }
        }
    }