How to reject delete statement in before delete trigger?

Question

How to reject delete statement in before delete trigger (mysql) ?

Sample use case : I have a record with specified id that I want to will not be deleted.

Answer 1

看这里，是一样的东西，但是带有一个插入触发器： 如何在MySql触发器中中止INSERT操作？

Answer 2

You could create a table that uses a foreign key constrait referencing your ID column (provided that is the primary key of your table). The insert a row into that "child" table that references ID = 0 and remove all update/delete privileges for your user from that table.

Now if someone tries to delete the row with ID = 0 in the "parent" table that will fail due to an existing child row in the other table.