CREATE TABLE IF NOT EXISTS `{PREFIX}_affiliatereferrers` (
  `user_id` bigint(20) DEFAULT NULL,
  `period` varchar(6) COLLATE utf8mb4_unicode_520_ci DEFAULT NULL,
  `url` varchar(255) COLLATE utf8mb4_unicode_520_ci DEFAULT NULL,
  `referred` bigint(20) DEFAULT '0',
  UNIQUE KEY `user_period_url` (`user_id`,`period`),
  KEY `user_id` (`user_id`),
  KEY `period` (`period`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_520_ci;