我想创建一个数据库,其中表药物和表项之间有n×m的关系,表目标和表项之间有n×m的关系。与mysql中的同一个表有两个n×m关系
我得到的错误:Cannot delete or update a parent row: a foreign key constraint fails
我必须在我的代码中更改什么?
DROP TABLE IF EXISTS `textmine`.`article`;
CREATE TABLE `textmine`.`article` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT COMMENT 'Pubmed ID',
`abstract` blob NOT NULL,
`authors` blob NOT NULL,
`journal` varchar(256) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
DROP TABLE IF EXISTS `textmine`.`drugs`;
CREATE TABLE `textmine`.`drugs` (
`id` int(10) unsigned NOT NULL COMMENT 'This ID is taken from the biosemantics dictionary',
`primaryName` varchar(256) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
DROP TABLE IF EXISTS `textmine`.`targets`;
CREATE TABLE `textmine`.`targets` (
`id` int(10) unsigned NOT NULL AUTO_INCREMENT,
`primaryName` varchar(256) CHARACTER SET utf8 COLLATE utf8_bin NOT NULL,
PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
DROP TABLE IF EXISTS `textmine`.`containstarget`;
CREATE TABLE `textmine`.`containstarget` (
`targetid` int(10) unsigned NOT NULL,
`articleid` int(10) unsigned NOT NULL,
KEY `target` (`targetid`),
KEY `article` (`articleid`),
CONSTRAINT `article` FOREIGN KEY (`articleid`) REFERENCES `article` (`id`),
CONSTRAINT `target` FOREIGN KEY (`targetid`) REFERENCES `targets` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
DROP TABLE IF EXISTS `textmine`.`contiansdrug`;
CREATE TABLE `textmine`.`contiansdrug` (
`drugid` int(10) unsigned NOT NULL,
`articleid` int(10) unsigned NOT NULL,
KEY `drug` (`drugid`),
KEY `article` (`articleid`),
CONSTRAINT `article` FOREIGN KEY (`articleid`) REFERENCES `article` (`id`),
CONSTRAINT `drug` FOREIGN KEY (`drugid`) REFERENCES `drugs` (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;
-1这绝对不是给定问题的解决方案。外键(参照完整性关系)是RDBMS的全部内容,并且绝对是一种不会强迫您更改设计的解决方案。 – Unreason 2010-04-03 10:43:20