ALTER TABLE `event_email_recipient`
ADD `event_id` INT(10) NULL,
ADD KEY `fk_event_recipient_event_id` (`event_id`),
ADD CONSTRAINT `fk_event_recipient_event_id` FOREIGN KEY (`event_id`) REFERENCES `event` (`event_id`) ON UPDATE CASCADE;

ALTER TABLE `event_email_schedule`
ADD `event_id` INT(10) NULL,
ADD KEY `fk_event_email_schedule_event_id` (`event_id`),
ADD CONSTRAINT `fk_event_email_schedule_event_id` FOREIGN KEY (`event_id`) REFERENCES `event` (`event_id`) ON UPDATE CASCADE;