MySQL: Cannot add or update a child row: a foreign key constraint fails - mysql

Question

I have a workflow in my application where an admin for an organization can add a user to their organization. Once a form submission, I first insert a new record into my user table with the users email and the organization id associated with the admin. After that user is created, a member record which connects the user to the organization is created with the users email and the users organization id and user_id. The issue I am running into is with creating a record on the member table with the recently created users user_id. While I have no issue storing the organization_id present, for some reason passing the user_id throws an error related to the foreign key:
Cannot add or update a child row: a foreign key constraint fails (`work`.`member`, CONSTRAINT `member_ibfk_2` FOREIGN KEY (`user_id`) REFERENCES `organization` (`organization_id`) ON DELETE CASCADE ON UPDATE CASCADE)]
Why can't I pass the user_id on record creation. Is it because the column is associated to a foreign key?
Here are the inserts:
User insert (No error):
INSERT INTO `user` (`user_id`,`email`,`organization_id`,`updatedAt`,`createdAt`) VALUES (DEFAULT,'test+email#gmail.com','1','2016-06-07 11:51:54','2016-06-07 11:51:54');
Member insert (Error with user_id):
INSERT INTO `member` (`member_id`,`member_email`,`organization_id`,`user_id`,`updatedAt`,`createdAt`) VALUES (DEFAULT,'test+email#gmail.com','1',8,'2016-06-07 11:51:54','2016-06-07 11:51:54');
User Table:
`user` (
`user_id` int(11) NOT NULL AUTO_INCREMENT,
`first_name` varchar(255) DEFAULT NULL,
`last_name` varchar(255) DEFAULT NULL,
`email` varchar(255) DEFAULT NULL,
`password` varchar(255) DEFAULT NULL,
`organization_id` int(11) DEFAULT NULL,
`authentication_token` varchar(255) DEFAULT NULL,
`reset_password_token` varchar(255) DEFAULT NULL,
`reset_password_expires` datetime DEFAULT NULL,
`createdAt` datetime NOT NULL,
`updatedAt` datetime NOT NULL,
PRIMARY KEY (`user_id`),
UNIQUE KEY `email` (`email`)
) ENGINE=InnoDB AUTO_INCREMENT=10 DEFAULT CHARSET=utf8;
Organization table:
`organization` (
`organization_id` int(11) NOT NULL AUTO_INCREMENT,
`organization_name` varchar(255) DEFAULT NULL,
`admin` varchar(255) DEFAULT NULL,
`createdAt` datetime NOT NULL,
`updatedAt` datetime NOT NULL,
PRIMARY KEY (`organization_id`)
) ENGINE=InnoDB AUTO_INCREMENT=2 DEFAULT CHARSET=utf8;
Member table:
`member` (
`member_id` int(11) NOT NULL AUTO_INCREMENT,
`member_email` varchar(255) DEFAULT NULL,
`organization_id` int(11) DEFAULT NULL,
`user_id` int(11) DEFAULT NULL,
`createdAt` datetime NOT NULL,
`updatedAt` datetime NOT NULL,
PRIMARY KEY (`member_id`),
UNIQUE KEY `member_email` (`member_email`),
UNIQUE KEY `member_user_id_organizationId_unique` (`organization_id`,`user_id`),
KEY `user_id` (`user_id`),
CONSTRAINT `member_ibfk_1` FOREIGN KEY (`organization_id`) REFERENCES `user` (`user_id`) ON DELETE CASCADE ON UPDATE CASCADE,
CONSTRAINT `member_ibfk_2` FOREIGN KEY (`user_id`) REFERENCES `organization` (`organization_id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB AUTO_INCREMENT=11 DEFAULT CHARSET=utf8;

Answer 1

Seem to me that you got your constraints mixed up.
I created the tables using your sql and reverse engineered with MySQLWorkbench to get an EER containing your tables.
On first sight you can see that organization_id in table organization is linked with user_id in members table.
If you change your constraints to the following, it will work:
CONSTRAINT `member_ibfk_1` FOREIGN KEY (`organization_id`) REFERENCES `organization` (`organization_id`) ON DELETE CASCADE ON UPDATE CASCADE,
CONSTRAINT `member_ibfk_2` FOREIGN KEY (`user_id`) REFERENCES `user` (`user_id`) ON DELETE CASCADE ON UPDATE CASCADE

Answer 2

Try to change the CONSTRAINT member_ibfk_1 to this:
CONSTRAINT `member_ibfk_1` FOREIGN KEY (`organization_id`) REFERENCES user(`user_id`) ON DELETE CASCADE ON UPDATE CASCADE,