Foreign key incorrectly formed error in MySQL in Manjaro Linux - mysql

Question

"user table" is created successfully. Every columns and types is the same as "users table." But when I create an association table named "user_role," "user table" cannot be called. I only get this error in using MySQL with MariaDB. Installing mysql in windows and using like that is fine. Without changing that table name, is there anything I can do to make it right?
Two tables are dumped because I forget where did I put my original code. But I'll be the same.
CREATE TABLE `user` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`email` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`name` varchar(255) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`course_id` bigint(20) DEFAULT NULL,
`password` varchar(100) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `FKj8ce5cjkm11igsffixdxexrr9` (`course_id`)
) ENGINE=MyISAM AUTO_INCREMENT=5 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE `users` (
`id` bigint(20) NOT NULL AUTO_INCREMENT,
`name` varchar(50) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`email` varchar(50) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
`course_id` bigint(20) DEFAULT NULL,
`password` varchar(100) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
PRIMARY KEY (`id`),
KEY `course_id` (`course_id`),
CONSTRAINT `users_ibfk_1` FOREIGN KEY (`course_id`) REFERENCES `course` (`id`) ON DELETE SET NULL) ENGINE=InnoDB AUTO_INCREMENT=9 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
CREATE TABLE `role` (
`id` int(11) NOT NULL AUTO_INCREMENT,
`role_name` varchar(50) COLLATE utf8mb4_unicode_ci DEFAULT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=3 DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;
create table `user_role`(
`id` int auto_increment not null,
`user_id_fk` bigint,
`role_id_fk` int,
primary key (`id`),
foreign key (`user_id_fk`) references `user`(`id`),
foreign key (`role_id_fk`) references `role`(`id`)
);
--> references user(id) is not working but references users(id) is working. Is there any way to make it work? Or just change the name?

Answer 1

Suggest you don't have one table name being the plural of another (user vs users); it can lead to typos.
Don't use MyISAM for anything. (with rare exceptions)
If that is a many-to-many mapping table follow the tips in http://mysql.rjweb.org/doc.php/index_cookbook_mysql#many_to_many_mapping_table

Answer 2

The foreign key is across tables defined with different engines(InnoDB and MyISAM):
create table `user_role`(
`id` int auto_increment not null,
`user_id_fk` bigint(20), -- matching data types
`role_id_fk` int(11) -- matching data types
,primary key (`id`)
,foreign key (`role_id_fk`) references `role`(`id`)
,foreign key (`user_id_fk`) references `user`(`id`)
);
db<>fiddle demo
Related: Why doesn't MySQL's MyISAM engine support Foreign keys?