mysql - 如何创建触发器以在更新该行时增加该列？

Question

每次更新此表的一行时，该行的“级别”单元格都必须增加 1。是否有触发器可以帮助解决此问题？

Answer 1

CREATE TRIGGER increment_level
BEFORE UPDATE
ON tablename
FOR EACH ROW
SET NEW.level = OLD.level + 1;

Is it possible to add an if loop which will check whether the status is ongoing or finished and the trigger level should only increment if status is ongoing?

CREATE TRIGGER increment_level
BEFORE UPDATE
ON tablename
FOR EACH ROW
SET NEW.level = OLD.level + (NEW.status = 'ongoing');