CREATE TABLE IF NOT EXISTS `alerts_maint_assoc` (`maint_assoc_id` int(11) NOT NULL AUTO_INCREMENT, `maint_id` int(11) NOT NULL, `entity_type` varchar(16) COLLATE utf8_unicode_ci NOT NULL, `entity_id` int(11) NOT NULL, PRIMARY KEY (`maint_assoc_id`), UNIQUE KEY `unique` (`maint_id`,`entity_type`,`entity_id`), KEY `maint_id` (`maint_id`)) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;