julia/core/models/Category.php

<?php

namespace Entity;

class Category extends ModelBase
{
    protected function install()
    {
        $dbPrefix = $this->getDbPrefix();
        $result = self::$dbo->exec("CREATE TABLE IF NOT EXISTS `{$dbPrefix}category` (
            `id` INTEGER(11) UNSIGNED NOT NULL AUTO_INCREMENT PRIMARY KEY,
            `parent_id` INTEGER(11) UNSIGNED NULL,
            FOREIGN KEY (`parent_id`) REFERENCES `{$dbPrefix}category`(id)
        )");
        if ($result === false)
            throw new \Exception(get_class().": ".self::$dbo->errorInfo()[2]);
        return true;
    }
}