MySQL 工作台 "errno 150 foreign key"

Question

SET @OLD_UNIQUE_CHECKS=@@UNIQUE_CHECKS, UNIQUE_CHECKS=0;
SET @OLD_FOREIGN_KEY_CHECKS=@@FOREIGN_KEY_CHECKS, FOREIGN_KEY_CHECKS=0;
SET @OLD_SQL_MODE=@@SQL_MODE, SQL_MODE='TRADITIONAL,ALLOW_INVALID_DATES';

CREATE SCHEMA IF NOT EXISTS `mydb` DEFAULT CHARACTER SET utf8 COLLATE 
utf8_general_ci ;
USE `mydb` ;

-- -----------------------------------------------------
-- Table `mydb`.`Diploma`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`Diploma` (
`diploma_id` VARCHAR(5) NOT NULL,
`diploma_name` VARCHAR(90) NULL,
PRIMARY KEY (`diploma_id`)
)  ENGINE=InnoDB;


-- -----------------------------------------------------
-- Table `mydb`.`School`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`School` (
`school_id` INT(1) NOT NULL,
`school_name` VARCHAR(45) NULL,
PRIMARY KEY (`school_id`)
)  ENGINE=InnoDB;


-- -----------------------------------------------------
-- Table `mydb`.`Student`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`Student` (
`student_number` INT(8) NOT NULL,
`student_id` INT(8) NULL,
`student_name` VARCHAR(45) NULL,
`student_password` VARCHAR(45) NULL,
`student_mobile` INT(8) NULL,
`student_email` VARCHAR(45) NULL,
`diploma_id` VARCHAR(5) NOT NULL,
`school_id` INT(1) NOT NULL,
PRIMARY KEY (`student_number`),
INDEX `fk_Student_Diploma1_idx` (`diploma_id` ASC),
INDEX `fk_Student_School1_idx` (`school_id` ASC),
CONSTRAINT `fk_Student_Diploma1` FOREIGN KEY (`diploma_id`)
    REFERENCES `mydb`.`Diploma` (`diploma_id`)
    ON DELETE NO ACTION ON UPDATE NO ACTION,
CONSTRAINT `fk_Student_School1` FOREIGN KEY (`school_id`)
    REFERENCES `mydb`.`School` (`school_id`)
    ON DELETE NO ACTION ON UPDATE NO ACTION
)  ENGINE=InnoDB;


-- -----------------------------------------------------
-- Table `mydb`.`OFN`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`OFN` (
`ofn_id` INT(8) NOT NULL,
`ofn_username` VARCHAR(45) NULL,
`ofn_password` VARCHAR(45) NULL,
`ofn_email` VARCHAR(45) NULL,
PRIMARY KEY (`ofn_id`)
)  ENGINE=InnoDB;


-- -----------------------------------------------------
-- Table `mydb`.`Appointment`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`Appointment` (
`appointment_id` INT(8) NOT NULL,
`appointment_date` DATE NULL,
`appointment_time` TIME NULL,
`ofn_id` INT(8) NOT NULL,
PRIMARY KEY (`appointment_id`),
INDEX `fk_Appointment_OFN1_idx` (`ofn_id` ASC),
CONSTRAINT `fk_Appointment_OFN1` FOREIGN KEY (`ofn_id`)
    REFERENCES `mydb`.`OFN` (`ofn_id`)
    ON DELETE NO ACTION ON UPDATE NO ACTION
)  ENGINE=InnoDB;


-- -----------------------------------------------------
-- Table `mydb`.`Booking`
-- -----------------------------------------------------
CREATE TABLE IF NOT EXISTS `mydb`.`Booking` (
`student_number` INT(8) NOT NULL,
`appointment_id` INT(8) NOT NULL,
`booking_date` DATE NULL,
`booking_time` TIME NULL,
PRIMARY KEY (`student_number` , `appointment_id`),
INDEX `fk_Student_has_Appointment_Appointment1_idx` (`appointment_id` ASC),
INDEX `fk_Student_has_Appointment_Student1_idx` (`student_number` ASC),
CONSTRAINT `fk_Student_has_Appointment_Student1` FOREIGN KEY 
 (`student_number`)
    REFERENCES `mydb`.`Student` (`student_number`)
    ON DELETE NO ACTION ON UPDATE NO ACTION,
CONSTRAINT `fk_Student_has_Appointment_Appointment1` FOREIGN KEY (`appointment_id`)
    REFERENCES `mydb`.`Appointment` (`appointment_id`)
    ON DELETE NO ACTION ON UPDATE NO ACTION
)  ENGINE=InnoDB;


SET SQL_MODE=@OLD_SQL_MODE;
SET FOREIGN_KEY_CHECKS=@OLD_FOREIGN_KEY_CHECKS;
SET UNIQUE_CHECKS=@OLD_UNIQUE_CHECKS;

这是我正在构建的代码，但它给出了一个错误 错误代码:1005:无法创建表“mydb”。“预订” 我尝试通过遇到相同问题的人浏览一些先前的问题，但我仍然停留在这一点上。 任何帮助将不胜感激，谢谢。

Answer 1

不知何故，它是外键 student_number。

我在考虑这些可能性:

1. 外键名称与已存在的键重复。检查外键的名称在数据库中是否唯一。只需在 key 名称的末尾添加一些随机字符即可对此进行测试。

2. 您的一个或两个表是 MyISAM 表。为了使用外键，表必须都是 InnoDB。 (实际上，如果两个表都是 MyISAM，那么您不会收到错误消息 - 它只是不会创建键。)在查询浏览器中，您可以指定表类型。

3. 您尝试引用的关键字段之一没有索引和/或不是主键。如果关系中的某个字段不是主键，则必须为该字段创建索引。

同时检查: SET FOREIGN_KEY_CHECKS=0;