建表的时候，报1005错误

Question

建表语句如下：
CREATE TABLE `my_notes`.`notes` (
  `id` INTEGER UNSIGNED NOT NULL AUTO_INCREMENT,
  `username` VARCHAR(16) NOT NULL,
  `post_time` DATETIME NOT NULL,
  `title` VARCHAR(32) NOT NULL,
  `content` TINYTEXT NOT NULL,
  PRIMARY KEY (`id`),
  CONSTRAINT `FK_notes_1` FOREIGN KEY `FK_notes_1` (`username`)
    REFERENCES `users` (`username`)
    ON DELETE CASCADE
    ON UPDATE CASCADE
)
ENGINE = InnoDB;

Answer 1

带FOREIGN KEY的表很麻烦，把users表结构贴上来

Answer 2

http://blog.csdn.net/yuandafeng/archive/2006/02/12/597535.aspx

Answer 3

mysql> desc users;
+----------+------------------+------+-----+---------+----------------+
| Field    | Type             | Null | Key | Default | Extra          |
+----------+------------------+------+-----+---------+----------------+
| id       | int(10) unsigned | NO   | PRI | NULL    | auto_increment |
| username | varchar(16)      | NO   |     |         |                |
| password | varchar(16)      | NO   |     |         |                |
+----------+------------------+------+-----+---------+----------------+
3 rows in set (0.19 sec)