引用我有两个表:MySQL的REPLACE行为不同于更新,如果主键是由外键
CREATE TABLE `category` (
`category_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`user_id` mediumint(8) unsigned NOT NULL,
`name` varchar(20) CHARACTER SET ascii NOT NULL,
`description` varchar(100) DEFAULT NULL,
`repeat_interval` tinyint(3) unsigned NOT NULL DEFAULT '0',
`color` mediumint(8) unsigned NOT NULL,
PRIMARY KEY (`category_id`),
KEY `id` (`user_id`),
CONSTRAINT `category_ibfk_1` FOREIGN KEY (`user_id`) REFERENCES `user` (`id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
CREATE TABLE `event` (
`event_id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`category_id` int(10) unsigned NOT NULL,
`name` varchar(20) CHARACTER SET ascii NOT NULL,
`description` varchar(100) DEFAULT NULL,
`repeat_interval` tinyint(3) unsigned NOT NULL DEFAULT '0',
`color` mediumint(8) unsigned NOT NULL,
`priority` tinyint(3) unsigned NOT NULL DEFAULT '0',
`start` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
`end` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
`done` tinyint(1) NOT NULL DEFAULT '0',
PRIMARY KEY (`event_id`),
KEY `category_id` (`category_id`),
CONSTRAINT `event_ibfk_1` FOREIGN KEY (`category_id`) REFERENCES `category` (`category_id`) ON DELETE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
如果我的类别表(1行)进行REPLACE
那么所有的条目在事件表中引用类别表中的修改行将被丢弃。
但是,如果我在类别表UPDATE
一排,然后在事件表中的条目保持不变。
为什么这种行为,为什么当我REPLACE
什么东西所有引用该列的条目都被丢弃?
我试着用ON UPDATE CASCADE
和默认的相同的行为。
Google无法帮助我。