我想創建一個數據庫,其中表藥物和表項之間有n×m的關係,表目標和表項之間有n×m的關係。與mysql中的同一個表有兩個n×m關係
我得到的錯誤:Cannot delete or update a parent row: a foreign key constraint fails
我必須在我的代碼中更改什麼?
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這絕對不是給定問題的解決方案。外鍵(參照完整性關係)是RDBMS的全部內容,並且絕對是一種不會強迫您更改設計的解決方案。 – Unreason 2010-04-03 10:43:20