错误 1215 MYSQL 无法添加外键约束, [英] error 1215 MYSQL Cannot add foreign key constraint,
本文介绍了错误 1215 MYSQL 无法添加外键约束,的处理方法,对大家解决问题具有一定的参考价值,需要的朋友们下面随着小编来一起学习吧!
问题描述
我有这个代码:
CREATE TABLE IF NOT EXISTS `biblioteca`.`ejemplar` (
`idejemplar` INT(11) NOT NULL AUTO_INCREMENT ,
`estado` VARCHAR(45) NOT NULL ,
`comentario` VARCHAR(45) NULL ,
`isbn` VARCHAR(45) NOT NULL ,
PRIMARY KEY (`idejemplar`) ,
INDEX `fk_ejemplar_libro1_idx` (`isbn` ASC) ,
CONSTRAINT `fk_ejemplar_libro1`
FOREIGN KEY (`isbn` )
REFERENCES `biblioteca`.`libro` (`isbn` )
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8
参考的表格是:
CREATE TABLE IF NOT EXISTS `biblioteca`.`libro` (
`isbn` VARCHAR(25) NOT NULL ,
`idcategoria` INT(11) NOT NULL ,
`ideditorial` INT(11) NOT NULL ,
`titulo` VARCHAR(45) NOT NULL ,
`autor` VARCHAR(45) NOT NULL ,
`reseña` VARCHAR(45) NULL ,
PRIMARY KEY (`isbn`) ,
INDEX `fk_libro2_idx` (`idcategoria` ASC) ,
INDEX `fk_libro3_idx` (`ideditorial` ASC) ,
CONSTRAINT `fk_libro2`
FOREIGN KEY (`idcategoria` )
REFERENCES `biblioteca`.`categoria` (`idcategoria` )
ON DELETE NO ACTION
ON UPDATE NO ACTION,
CONSTRAINT `fk_libro3`
FOREIGN KEY (`ideditorial` )
REFERENCES `biblioteca`.`editorial` (`ideditorial` )
ON DELETE CASCADE
ON UPDATE CASCADE)
ENGINE = InnoDB
DEFAULT CHARACTER SET = utf8;
我认为外键很好.
推荐答案
如果这些是没有值的新表,列似乎有错误
If these are fresh tables with no values, It seems like an error with the columns
一个有一个 varchar(25) 另一个有一个 var_char(45) 使它们相同
one has a varchar(25) the other a var_char(45) make them the same
CREATE TABLE IF NOT EXISTS `biblioteca`.`libro` (
`isbn` VARCHAR(45) NOT NULL ,
`idcategoria` INT(11) NOT NULL ,
`ideditorial` INT(11) NOT NULL ,
`titulo` VARCHAR(45) NOT NULL ,
`autor` VARCHAR(45) NOT NULL ,
`reseña` VARCHAR(45) NULL ,
PRIMARY KEY (`isbn`) ,
INDEX `fk_libro2_idx` (`idcategoria` ASC) ,
INDEX `fk_libro3_idx` (`ideditorial` ASC) )
ENGINE = INNODB
DEFAULT CHARACTER SET = utf8;
CREATE TABLE IF NOT EXISTS `biblioteca`.`ejemplar` (
`idejemplar` INT(11) NOT NULL AUTO_INCREMENT ,
`estado` VARCHAR(45) NOT NULL ,
`comentario` VARCHAR(45) NULL ,
`isbn` VARCHAR(45) NOT NULL ,
PRIMARY KEY (`idejemplar`) ,
INDEX `fk_ejemplar_libro1_idx` (`isbn` ASC) ,
CONSTRAINT `fk_ejemplar_libro1`
FOREIGN KEY (`isbn` )
REFERENCES `biblioteca`.`libro` (`isbn` )
ON DELETE NO ACTION
ON UPDATE NO ACTION)
ENGINE = INNODB
DEFAULT CHARACTER SET = utf8;
对我来说没问题.我已经拿走了我没有架构的其他 2 个键
works no problem for me. Ive taken away the other 2 keys which i dont have schemas for though
这篇关于错误 1215 MYSQL 无法添加外键约束,的文章就介绍到这了,希望我们推荐的答案对大家有所帮助,也希望大家多多支持IT屋!
查看全文