CREATE TABLE `assessmentbookdb`.`MCQs` (
`id` INT NOT NULL AUTO_INCREMENT ,
`MCQAnswer` VARCHAR(200) NOT NULL ,
`QuestionID` INT NOT NULL ,
PRIMARY KEY (`id`) ,
INDEX `QuestionID` (`QuestionID` ASC) ,
CONSTRAINT `QuestionID`
FOREIGN KEY (`QuestionID`)
REFERENCES `assessmentbookdb`.`Question` (`QuestionID`)
ON DELETE CASCADE
ON UPDATE CASCADE)
ENGINE = InnoDB;
消息日志表:MySQL不能创建外键
错误1005:无法创建表 'assessmentbookdb.mcqs'(错误:121) SQL语句:
CREATE TABLE `assessmentbookdb`.`MCQs` (
`id` INT NOT NULL AUTO_INCREMENT ,
`MCQAnswer` VARCHAR(200) NOT NULL ,
`QuestionID` INT NOT NULL ,
PRIMARY KEY (`id`) ,
INDEX `QuestionID` (`QuestionID` ASC) ,
CONSTRAINT `QuestionID`
FOREIGN KEY (`QuestionID`)
REFERENCES `assessmentbookdb`.`Question` (`QuestionID`)
ON DELETE CASCADE
ON UPDATE CASCADE)
ENGINE = InnoDB
问题表已存在,QuestionID是问题表的主键。我找不到有什么问题 – 2012-08-02 10:37:31