[英]mysql - foreign key cascade update
我有一个关于如何使用第二个字段作为约束的级联更新字段的问题。
结构是这样的(我删除了不必要的列):
具有idNode
和idDimension
列的表nodes
(它们一起构成主键)。
表forces
使用idForce
(PK), idNode
( nodes
外键idNode
)和idDimension
。
级联更新和删除所有内容。
这种结构中似乎出现的问题是:
如果在nodes
我有一个条目(1,1)和一个类似(1,2)且在forces
(1,1,1)和(1,1,2)中并且我从nodes
更新或删除了第一个条目在forces
将受到影响。
我只需要影响也具有相应idDimension的那个。 我该如何修改当前结构?
编辑:表格-节点:
CREATE TABLE IF NOT EXISTS `nodes` (
`idNode` varchar(11) NOT NULL,
`idDimension` int(10) unsigned NOT NULL,
`idNetwork` int(10) unsigned NOT NULL DEFAULT '0',
`level` int(11) unsigned NOT NULL DEFAULT '0',
`energy` bigint(20) DEFAULT NULL,
`resources` bigint(20) unsigned NOT NULL DEFAULT '0',
`x` int(11) NOT NULL,
`y` int(11) NOT NULL,
`name` varchar(20) DEFAULT NULL,
`order` tinyint(3) DEFAULT '0' COMMENT 'energy 0\nassemble 1\nupgrade 2',
`core` tinyint(1) unsigned NOT NULL DEFAULT '0',
PRIMARY KEY (`idNode`,`idDimension`),
KEY `network_dimension` (`idDimension`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 COMMENT='Node table';
军队:
CREATE TABLE IF NOT EXISTS `forces` (
`idForce` bigint(10) unsigned NOT NULL AUTO_INCREMENT,
`idNode` varchar(11) NOT NULL,
`idDimension` int(10) unsigned NOT NULL,
`drones` bigint(20) DEFAULT NULL,
`stance` tinyint(3) DEFAULT NULL COMMENT '0 - defense\n1 - neutral\n2 - attack \n\nIf planet is parano and you are not allied to owner you can only be in attack.\n\nIf owner is allied you can only be in defense or neutral.\n\nIf you are owner you can only be in defense.',
`order` tinyint(3) DEFAULT '0' COMMENT 'extract energy 1\nbuild node 2\nreplicate 3\nmove 4',
`value` text,
PRIMARY KEY (`idForce`),
KEY `idNode` (`idNode`,`idDimension`),
KEY `idDimension` (`idDimension`)
) ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=4 ;
-
forces
ALTER TABLE `forces`
ADD CONSTRAINT `forces_ibfk_2` FOREIGN KEY (`idDimension`) REFERENCES `nodes` (`idDimension`) ON DELETE CASCADE ON UPDATE CASCADE,
ADD CONSTRAINT `fk_forces_nodes1` FOREIGN KEY (`idNode`, `idDimension`) REFERENCES `nodes` (`idNode`, `idDimension`) ON DELETE NO ACTION ON UPDATE NO ACTION,
ADD CONSTRAINT `forces_ibfk_1` FOREIGN KEY (`idNode`) REFERENCES `nodes` (`idNode`) ON DELETE CASCADE ON UPDATE CASCADE;
我的约束无法正常运行,请随时忽略它们:)。
有两个奇怪的外键( forces_ibfk_1
和forces_ibfk_2
),它们引用非唯一字段。 删除它们-
ALTER TABLE forces DROP FOREIGN KEY forces_ibfk_1;
ALTER TABLE forces DROP FOREIGN KEY forces_ibfk_2;
然后使用CASCADE操作选项重新创建引用唯一字段对的fk_forces_nodes1
ALTER TABLE forces
DROP FOREIGN KEY fk_forces_nodes1;
ALTER TABLE orces
ADD CONSTRAINT fk_forces_nodes1 FOREIGN KEY (idNode, idDimension)
REFERENCES nodes(idNode, idDimension) ON DELETE CASCADE ON UPDATE CASCADE;
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.