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我得到一個錯誤,指出:Error Code: 1217. Cannot delete or update a parent row: a foreign key constraint fails
外鍵約束失敗(MySQL)
不知道爲什麼我得到這個錯誤。任何線索?下面
代碼:
-- DROP EXISTING TABLES --
DROP TABLE IF EXISTS `category`;
DROP TABLE IF EXISTS `format`;
DROP TABLE IF EXISTS `customer`;
DROP TABLE IF EXISTS `rentals`;
DROP TABLE IF EXISTS `videos`;
-- CREATE CATEGORY TABLE --
CREATE TABLE `category` (
`category_id` int(10) NOT NULL,
PRIMARY KEY (`category_id`)
) ENGINE = InnoDB DEFAULT CHARSET = utf8;
-- CREATE FORMAT TABLE --
CREATE TABLE `format` (
`format_id` int(10) NOT NULL,
PRIMARY KEY (`format_id`)
) ENGINE = InnoDB DEFAULT CHARSET = utf8;
-- CRTEATE VIDEOS TABLE --
CREATE TABLE `videos` (
`video_id` int(10) NOT NULL,
`title` varchar(50) NOT NULL,
`format_id` int(10) NOT NULL,
`cost` double NOT NULL,
`category_id` int(10) NOT NULL,
PRIMARY KEY (`video_id`),
CONSTRAINT `fk_video_format` FOREIGN KEY (`format_id`) REFERENCES `format` (`format_id`),
CONSTRAINT `fk_video_category` FOREIGN KEY (`category_id`) REFERENCES `category` (`category_id`)
) ENGINE = InnoDB DEFAULT CHARSET = utf8;
-- CREATE CUSTOMER TABLE --
CREATE TABLE `customer` (
`customer_id` int(10) NOT NULL,
`last_name` varchar(50) NOT NULL,
`first_name` varchar(50) NOT NULL,
`address` varchar(100) NOT NULL,
`city` varchar(50) NOT NULL,
`state` varchar(10) NOT NULL,
`zip` int(10) NOT NULL,
PRIMARY KEY (`customer_id`)
) ENGINE = InnoDB DEFAULT CHARSET = utf8;
-- CREATE RENTALS TABLE --
CREATE TABLE `rentals` (
`rental_id` int(10) NOT NULL,
`date_out` datetime NOT NULL,
`date_due` datetime NOT NULL,
`date_in` datetime NOT NULL,
`delivery_status` varchar(50),
`cost` double NOT NULL,
`late_fee` double NOT NULL,
`customer_id` int(10) NOT NULL,
`video_id` int(10) NOT NULL,
PRIMARY KEY (`rental_id`),
CONSTRAINT `fk_video_customer` FOREIGN KEY (`customer_id`) REFERENCES `customer` (`customer_id`),
CONSTRAINT `fk_video_cost` FOREIGN KEY (`cost`) REFERENCES `videos` (`cost`),
CONSTRAINT `fk_video_id` FOREIGN KEY (`video_id`) REFERENCES `videos` (`video_id`)
) ENGINE = InnoDB DEFAULT CHARSET = utf8;
我相信一切鍵和外鍵明智相匹配。格式也看起來正確。除非我在這裏做了完全錯誤的事情。
'fk_video_cost參考視頻(成本)' - 你真的打算成本是一個關鍵? – jdigital
@jdigital哦!謝謝!我剛剛開始學習MySQL,並試圖完善我的學習。非常感謝! :) – Donson
您可能會發現一次執行一條sql語句有助於縮小問題的範圍。 – jdigital