如何使用phpMyAdmin添加指向同一个表的外键？ [英] how do I add a foreign key pointing to the same table using phpMyAdmin?

问题描述

我有一个现有的InnoDB表，已经有外键指向不同的表。

但是当我尝试创建一个指向主索引的外键时，得到一个错误（检查数据类型）。

这个表是以User_Id为主的User。

I想要一个外键Manager_ID这是一个FK到User_Id。

两个
两个长度10
无符号...

但是我仍然得到一个数据检查错误...？

解决方案

Manager_ID不是 设置为 NOT NULL 。

您必须允许nulls那个领域，作为公司最顶层的人将没有经理。

我找到了 a post over the MySQL boards that may help help。

I have an existing InnoDB table which already has foreign keys pointing to different tables.

But when I try to create a foreign key pointing to the Primary index, I get an error (check data type).

The table is User with User_Id as the Primary.

I want a foreign key Manager_ID which is a FK to User_Id.

Both of INT Both of Length 10 Unsigned...

But I still get a data check error...?

解决方案

Make sure that Manager_ID is not set to NOT NULL.

You have to allow nulls on that field, as the top-most person in the company will have no manager.

I found a post over on the MySQL boards that might help.

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