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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