如何在删除触发器之前拒绝删除语句? [英] How to reject delete statement in before delete trigger?

问题描述

如何在删除触发器之前在拒绝删除语句(mysql)?

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

示例用例:我有一个记录，该记录具有指定的 id ，我希望将其删除.

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

推荐答案

您可以创建一个表，该表使用引用ID列(假定是表的主键)的外键约束.在引用ID = 0的子"表中插入一行，并从该表中删除用户的所有更新/删除特权.

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.

现在，如果有人尝试删除父"表中ID = 0的行，由于另一表中已有子行，该行将失败.

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.

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