MySQL 触发器问题:仅在更改列时触发?

MySQL Trigger question: only trigger when a column is changed?(MySQL 触发器问题:仅在更改列时触发?)

问题描述

我不知道这是否可行，但我在表中有一个名为 active 的列.每当活动列更改时，我想重置 date 列中的日期，但 仅 如果 active 列更改.

I don't know if this is possible, but I have a column named active in a table. Whenever the active column gets changed, I would like to reset the date in the date column, but ONLY if the active column gets changed.

如果其他列发生了变化，但 active 列没有发生变化，那么日期将保持不变.

If other columns are changed but not the active column, then the date would remain the same.

推荐答案

类似的东西

DELIMITER //
 CREATE TRIGGER updtrigger BEFORE UPDATE ON mytable
     FOR EACH ROW
     BEGIN
     IF NEW.active <> OLD.active THEN
     SET NEW.date = '';     
     END IF;
     END
     //

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