エラー：エラー＃1215：外部キー制約を追加できません

Question

これは、スキーマをデータベースに転送する際に発生するエラーです。

ERROR: Error 1215: Cannot add foreign key constraint.

私はこのチェックリストを作成しましたが、私はこれらのどれも信じていません。

Db InnoDBはありますか？はい

すべてのテーブルがInnoDBですか？はい

参照テーブルにユニークなインデックスがありますか？はい

参照されて参照する列は、まったく同じ型ですか？

はい、私も試してみました：

ENGINE=InnoDB DEFAULT CHARSET=latin1 AUTO_INCREMENT=1; 

保証テーブルの最後に。まだ動作しません。

私はそれが保証のテーブルのどこかにあると思うので、ここでは完全なスクリプトですが、私が試したものはすべて動作しません。

--------------------------------------------------------------------------- 

-- MySQL Workbench Forward Engineering 

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'; 

-- ----------------------------------------------------- 
-- Schema mydb 
-- ----------------------------------------------------- 

-- ----------------------------------------------------- 
-- Schema mydb 
-- ----------------------------------------------------- 
CREATE SCHEMA IF NOT EXISTS `mydb` DEFAULT CHARACTER SET utf8 ; 
USE `mydb` ; 

-- ----------------------------------------------------- 
-- Table `mydb`.`warranty` 
-- ----------------------------------------------------- 
DROP TABLE IF EXISTS `mydb`.`warranty` ; 

CREATE TABLE IF NOT EXISTS `mydb`.`warranty` (
    `warranty_id` VARCHAR(255) NOT NULL, 
    `warranty_number` VARCHAR(25) NOT NULL COMMENT 'Warranty Number', 
    `warranty_effective_date` DATETIME NOT NULL COMMENT 'Warranty Effective Date', 
    `payment_option` VARCHAR(100) NOT NULL COMMENT 'Pay monthly or annunally, or all at once', 
    `total_amount` DOUBLE NOT NULL COMMENT 'Total Warranty Amount\n', 
    `active` TINYINT(1) NOT NULL, 
    `date_created` DATETIME NOT NULL, 
    `additional_information` LONGTEXT NULL COMMENT 'Additional information for finance, and car dealership.\nWill not be seen by customer', 
    PRIMARY KEY (`warranty_id`)) 
ENGINE = InnoDB; 

-- ----------------------------------------------------- 
-- Table `mydb`.`warranty_edit` 
-- ----------------------------------------------------- 
DROP TABLE IF EXISTS `mydb`.`warranty_edit` ; 

CREATE TABLE IF NOT EXISTS `mydb`.`warranty_edit` (
    `warranty_edit_id` VARCHAR(255) NOT NULL, 
    `fk_warranty_id_3` VARCHAR(255) NOT NULL COMMENT 'Foreign Key to warranty table', 
    `edited_table_name` VARCHAR(45) NOT NULL COMMENT 'Name of the table that was updated', 
    `edited_date` DATETIME NOT NULL COMMENT 'When record is inserted into DB', 
    `edited_by` VARCHAR(45) NOT NULL COMMENT 'Who updated the records', 
    `additional_information` LONGTEXT NULL COMMENT 'Extra information if needed', 
    PRIMARY KEY (`warranty_edit_id`), 
    INDEX `policy_id_idx` (`fk_warranty_id_3` ASC), 
    CONSTRAINT `warranty_id` 
    FOREIGN KEY (`fk_warranty_id_3`) 
    REFERENCES `mydb`.`warranty` (`warranty_id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION) 
ENGINE = InnoDB; 


-- ----------------------------------------------------- 
-- Table `mydb`.`bill` 
-- ----------------------------------------------------- 
DROP TABLE IF EXISTS `mydb`.`bill` ; 

CREATE TABLE IF NOT EXISTS `mydb`.`bill` (
    `bill_id` VARCHAR(255) NOT NULL, 
    `fk_warranty_id_1` VARCHAR(255) NOT NULL COMMENT 'Foreign Key of bill table', 
    `due_date` DATETIME NOT NULL COMMENT 'Payment due date', 
    `minimum_payment` DOUBLE NOT NULL COMMENT 'Minimum payment or per bill payment', 
    `created_date` DATETIME NOT NULL COMMENT 'Bill generated date', 
    `balance` DOUBLE NOT NULL COMMENT 'Customer makes partial payment, this has remaining balance', 
    `status` VARCHAR(45) NOT NULL COMMENT 'Paid, or Unpaid', 
    PRIMARY KEY (`bill_id`), 
    INDEX `warranty_id_idx` (`fk_warranty_id_1` ASC), 
    CONSTRAINT `warranty_id` 
    FOREIGN KEY (`fk_warranty_id_1`) 
    REFERENCES `mydb`.`warranty` (`warranty_id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION) 
ENGINE = InnoDB; 


-- ----------------------------------------------------- 
-- Table `mydb`.`vehicle` 
-- ----------------------------------------------------- 
DROP TABLE IF EXISTS `mydb`.`vehicle` ; 

CREATE TABLE IF NOT EXISTS `mydb`.`vehicle` (
    `vehicle_id` VARCHAR(255) NOT NULL COMMENT 'Foreign Key to Warranty Table', 
    `fk_warranty_id_2` VARCHAR(255) NOT NULL, 
    `year` CHAR(4) NOT NULL COMMENT 'Year of Car', 
    `make` VARCHAR(45) NOT NULL, 
    `model` VARCHAR(45) NOT NULL COMMENT 'Model', 
    `color` VARCHAR(45) NULL COMMENT 'Color', 
    `trim` VARCHAR(45) NULL COMMENT 'Trim', 
    `milage` INT NOT NULL COMMENT 'Mileage', 
    `vin_number` VARCHAR(20) NOT NULL COMMENT 'VIN Number', 
    `vehicle_plate_number` VARCHAR(20) NOT NULL COMMENT 'Registered Plate', 
    `vehicle_registered_state` VARCHAR(45) NOT NULL COMMENT 'Registered State', 
    `aftermarket_parts` VARCHAR(45) NULL COMMENT 'After Market Parts Not Included (Information)', 
    `created_date` DATETIME NOT NULL COMMENT 'Created Date', 
    PRIMARY KEY (`vehicle_id`), 
    INDEX `warranty_id_idx` (`fk_warranty_id_2` ASC), 
    CONSTRAINT `warranty_id` 
    FOREIGN KEY (`fk_warranty_id_2`) 
    REFERENCES `mydb`.`warranty` (`warranty_id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION) 
ENGINE = InnoDB; 


-- ----------------------------------------------------- 
-- Table `mydb`.`coverage` 
-- ----------------------------------------------------- 
DROP TABLE IF EXISTS `mydb`.`coverage` ; 

CREATE TABLE IF NOT EXISTS `mydb`.`coverage` (
    `coverage_id` VARCHAR(255) NOT NULL, 
    `coverage_package` VARCHAR(45) NOT NULL COMMENT 'Name of the package selected', 
    `fk_vehicle_id` VARCHAR(255) NOT NULL, 
    `detuctible` FLOAT NOT NULL, 
    `terms` VARCHAR(45) NOT NULL, 
    PRIMARY KEY (`coverage_id`), 
    INDEX `vehicle_id_idx` (`fk_vehicle_id` ASC), 
    CONSTRAINT `vehicle_id` 
    FOREIGN KEY (`fk_vehicle_id`) 
    REFERENCES `mydb`.`vehicle` (`vehicle_id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION) 
ENGINE = InnoDB; 


-- ----------------------------------------------------- 
-- Table `mydb`.`warranty_coverage` 
-- ----------------------------------------------------- 
DROP TABLE IF EXISTS `mydb`.`warranty_coverage` ; 

CREATE TABLE IF NOT EXISTS `mydb`.`warranty_coverage` (
    `warranty_coverage_id` VARCHAR(255) NOT NULL, 
    `fk_warranty_id_4` VARCHAR(255) NOT NULL, 
    `fk_coverage_id` VARCHAR(255) NOT NULL, 
    `active` TINYINT(1) NOT NULL, 
    PRIMARY KEY (`warranty_coverage_id`), 
    INDEX `warranty_id_idx` (`fk_warranty_id_4` ASC), 
    INDEX `coverage_id_idx` (`fk_coverage_id` ASC), 
    CONSTRAINT `warranty_id` 
    FOREIGN KEY (`fk_warranty_id_4`) 
    REFERENCES `mydb`.`warranty` (`warranty_id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION, 
    CONSTRAINT `coverage_id` 
    FOREIGN KEY (`fk_coverage_id`) 
    REFERENCES `mydb`.`coverage` (`coverage_id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION) 
ENGINE = InnoDB; 


-- ----------------------------------------------------- 
-- Table `mydb`.`payment` 
-- ----------------------------------------------------- 
DROP TABLE IF EXISTS `mydb`.`payment` ; 

CREATE TABLE IF NOT EXISTS `mydb`.`payment` (
    `payment_id` VARCHAR(255) NOT NULL, 
    `fk_bill_id` VARCHAR(255) NOT NULL COMMENT 'Foreign Key to bill table', 
    `paid_date` DATETIME NOT NULL COMMENT 'Payment made date', 
    `amount` DOUBLE NOT NULL COMMENT 'How much is paid', 
    `payment_method` VARCHAR(100) NOT NULL COMMENT 'Credit/Debit/Check/E-Withdrawl', 
    `payer_first_name` VARCHAR(45) NULL, 
    `payer_last_name` VARCHAR(45) NULL COMMENT 'Payer Last Name', 
    `card_number` VARCHAR(45) NULL COMMENT 'Credit or Debit Card Number', 
    `zip_code` VARCHAR(10) NULL, 
    `card_expiration_date` VARCHAR(10) NULL COMMENT 'Expiration Date of Credit Card', 
    `card_type` VARCHAR(25) NULL COMMENT 'Visa, Mastercard, American Express, Discover, other', 
    `debit_or_credit` VARCHAR(45) NULL COMMENT 'Is the card debit or credit', 
    `bank_name` VARCHAR(100) NULL COMMENT 'Bank Name for E-Withdrawal', 
    `account_number` VARCHAR(20) NULL COMMENT 'Account Number of Payer', 
    `routing_number` VARCHAR(20) NULL COMMENT 'Bank Routing Number', 
    `check_number` VARCHAR(20) NULL, 
    `addition_information` LONGTEXT NULL, 
    `created_date` DATETIME NOT NULL COMMENT 'When the payment is created', 
    PRIMARY KEY (`payment_id`), 
    INDEX `bill_id_idx` (`fk_bill_id` ASC), 
    CONSTRAINT `bill_id` 
    FOREIGN KEY (`fk_bill_id`) 
    REFERENCES `mydb`.`bill` (`bill_id`) 
    ON DELETE NO ACTION 
    ON UPDATE NO ACTION) 
ENGINE = InnoDB 
COMMENT = ' '; 


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

Answer 1

あなたはMySQLのCLIで次のコマンドを実行し、LATEST FOREIGN KEY ERRORセクションまでスクロールして特定のエラーを見つけることができます：

SHOW ENGINE INNODB STATUS\G 

各外部キー制約は、ユニークな名前を持っている必要があります。あなたのケースでは、全く同じ名前（warranty_id）の4つの外部キー制約があるため、CREATE TABLEステートメントは最初のステートメントを除くすべてのステートメントに失敗します。