改变视图有什么问题？

ALTER ALGORITHM = UNDEFINED DEFINER = `root`@`localhost` SQL SECURITY
DEFINER VIEW `patient_dentist` AS

SELECT `patients`.`office_id` AS `office_id`
    ,`patients`.`id` AS `patient_id`
    ,`patients`.`dentist_id` AS `dentist_id`
    ,`patients`.`dentist2_id` AS `dentist2_id`
    ,`patients`.`dentist3_id` AS `dentist3_id`
FROM `patients`
WHERE (
        (`patients`.`dentist_id` IS NOT NULL)
        AND isnull(`patients`.`deleted_at`)
        )

UNION

SELECT DISTINCT `reservations`.`office_id` AS `office_id`
    ,`reservations`.`patient_id` AS `patient_id`
    ,`reservations`.`staff_id` AS `dentist_id`
FROM `reservations`
WHERE (
        (`reservations`.`patient_id` IS NOT NULL)
        AND (`reservations`.`staff_id` IS NOT NULL)
        AND isnull(`reservations`.`deleted_at`)
        );
ALTER ALGORITHM = UNDEFINED DEFINER = `root`@`l