MySQL触发问题:仅当列更改时触发? [英] MySQL Trigger question: only trigger when a column is changed?

问题描述

我不知道这是否可行，但是我在表中有一列名为active的列.每当活动列被更改时，我都想重置date列中的日期，但是如果active列被更改，则仅.

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.

如果其他列已更改，但active列未更改，则日期将保持不变.

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

推荐答案

类似

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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