mysql 触发器阻止删除,如何编写触发器以中止MYSQL中的删除？

I read this article but it seems not work for delete. I got this error when tried to create a trigger:

Executing SQL script in server

ERROR: Error 1363: There is no NEW row in on DELETE trigger

CREATE TRIGGER DeviceCatalog_PreventDeletion

BEFORE DELETE on DeviceCatalog

FOR EACH ROW

BEGIN

DECLARE dummy INT;

IF old.id = 1 or old.id =2 THEN

SELECT * FROM DeviceCatalog WHERE DeviceCatalog.id=NEW.id;

END IF;

END;

SQL script execution finished: statements: 4 succeeded, 1 failed

解决方案

Try something like this -

DELIMITER $$

CREATE TRIGGER trigger1

BEFORE DELETE

ON table1

FOR EACH ROW

BEGIN

IF OLD.id = 1 THEN -- Abort when trying to remove this record

CALL cannot_delete_error; -- raise an error to prevent deleting from the table

END IF;

END

$$

DELIMITER ;