Mysql 即使所有行都是InnoDB且存在外键，也无法添加或更新子行

在尝试插入记录时，我得到：

错误1452（23000）：无法添加或更新子行：外键约束失败

涉及的两个表都是InnoDB。有问题的外键在另一个表中。字符集匹配。没有明显的原因

CREATE TABLE `Client` (
  `id` varchar(40) NOT NULL,
  `createdDate` datetime NOT NULL,
  `modifiedDate` datetime NOT NULL,
  `name` varchar(255) NOT NULL,
  `disabled` tinyint(1) NOT NULL DEFAULT '1',
  `deleted` tinyint(1) NOT NULL DEFAULT '0',
  PRIMARY KEY (`id`)
  ) ENGINE=InnoDB DEFAULT CHARSET=latin1

CREATE TABLE `User` (
  `id` varchar(40) NOT NULL,
  `userName` varchar(255) DEFAULT NULL,
  `clientId` varchar(40) NOT NULL,
  PRIMARY KEY (`id`),
  KEY `clientId` (`clientId`),
  CONSTRAINT `user_ibfk_1` FOREIGN KEY (`clientId`) REFERENCES `client` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1

select * from Client;
+--------------------------------------+---------------------+---------------------+------+----------+---------+
| id                                   | createdDate         | modifiedDate        | name | disabled | deleted |
+--------------------------------------+---------------------+---------------------+------+----------+---------+
| 24d2e2da-933c-11e3-8665-e1550725a2bd | 2014-02-19 16:21:45 | 2014-02-19 16:21:45 | MWS  |        0 |       0 |
+--------------------------------------+---------------------+---------------------+------+----------+---------+
1 row in set (0.00 sec)

INSERT INTO User (id,userName,clientId) VALUES ('eb124fde-8c85-11e3-894d-a29c2afd7657','ausername','24d2e2da-933c-11e3-8665-e1550725a2bd');
ERROR 1452 (23000): Cannot add or update a child row: a foreign key constraint fails (`minerva_portal`.`User`, CONSTRAINT `user_ibfk_1` FOREIGN KEY (`clientId`) REFERENCES `client` (`id`))

---

我完全不知所措。发生了什么？

显然，在这种情况下，错误是其他问题的幻影。我很沮丧，放弃了数据库，并从以前的sql转储读取了它。这个问题逐渐消失了