db->query(" CREATE TABLE `invitations` ( `user` int(8) unsigned NOT NULL, `key` varchar(16) CHARACTER SET ascii NOT NULL, `date` int(11) unsigned NOT NULL, PRIMARY KEY (`key`), KEY `user` (`user`), KEY `date` (`date`) ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_bin "); $this->db->query(" ALTER TABLE `users` ADD `referrer` INT(8) UNSIGNED NOT NULL DEFAULT '0' "); } public function down() { $this->db->query(" ALTER TABLE `users` DROP `referrer` "); $this->dbforge->drop_table('invitations'); } }