无法在 mysql 中分配 On Delete Set null 和 on updated set Null

Question

bank_api_uat_user Table

CREATE TABLE IF NOT EXISTS `bank_api_uat_user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `bank_name` varchar(255) DEFAULT NULL,
  `role` varchar(10) NOT NULL,
  `bank_code` char(10) NOT NULL,
  `user_name` varchar(255) NOT NULL,
  `password` varchar(20) NOT NULL,
  `api_key` varchar(255) NOT NULL,
  `Client_Secret` varchar(255) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `user_name` (`user_name`),
  KEY `user_name_2` (`user_name`),
  KEY `id` (`id`,`user_name`),
  KEY `role` (`role`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=36 ;

create_role Table

CREATE TABLE IF NOT EXISTS `create_role` (
  `date` datetime NOT NULL,
  `Role_name` varchar(50) NOT NULL,
  `Role_code` varchar(5) NOT NULL,
  PRIMARY KEY (`Role_code`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1;

我想将参照完整性分配给 bank_api_uat_user table 每次我添加约束时它都会给出以下错误 MySQL 说：文档

1215 - 无法添加外键约束

下面的查询用于创建外键。

ALTER TABLE `bank_api_uat_user` ADD  CONSTRAINT `const_file_role` FOREIGN KEY (`role`) REFERENCES `test`.`create_role`(`Role_code`) ON DELETE SET NULL ON UPDATE SET NULL;

Answer 1

将子列设为 Null 以设置空引用选项很重要。

如果角色声明为 NULL

，上述查询有效

CREATE TABLE IF NOT EXISTS `bank_api_uat_user` (
  `id` int(11) NOT NULL AUTO_INCREMENT,
  `bank_name` varchar(255) DEFAULT NULL,
  `role` varchar(10) NULL,
  `bank_code` char(10) NOT NULL,
  `user_name` varchar(255) NOT NULL,
  `password` varchar(20) NOT NULL,
  `api_key` varchar(255) NOT NULL,
  `Client_Secret` varchar(255) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `user_name` (`user_name`),
  KEY `user_name_2` (`user_name`),
  KEY `id` (`id`,`user_name`),
  KEY `role` (`role`)
) ENGINE=InnoDB  DEFAULT CHARSET=latin1 AUTO_INCREMENT=36 ;

完整的解释可以在这里找到：https://dev.mysql.com/doc/refman/5.7/en/create-table-foreign-keys.html

无法在 mysql 中分配 On Delete Set null 和 on updated set Null

Not able to assign On Delete Set null and on updated set Null in mysql

php

mysql

referential-integrity

1215 - 无法添加外键约束