Two n x m relationships with the same table in mysql
- by Christian
I want to create a database in which there's an n x m relationship between the table drug and the table article and an n x m relationship between the table target and the table article.
I get the error: Cannot delete or update a parent row: a foreign key constraint fails
What do I have to change in my code?
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;
