MySQL-為什么我不能在這里添加外鍵？

Question

我不確定為什么我不能在這里添加特定的外鍵。 這些表是通過MySQL Workbench生成的，並且基於MySQL文檔以及在搜索其他類似問題/解決方案時，我認為一切都井井有條...但是我不能特別添加一個外鍵：

inspection_statuses 。 inspection_id需要引用inspection_responses 。 tpa_result

我想念/忽視什么？

這是我要用來添加新外鍵的語句：

ALTER TABLE `vipsouth_app`.`inspection_statuses` 
ADD CONSTRAINT `inspection_statuses_ibfk_3`
  FOREIGN KEY (`inspection_id`)
  REFERENCES `vipsouth_app`.`inspection_responses` (`tpa_result`)
  ON DELETE NO ACTION
  ON UPDATE NO ACTION;

並產生此錯誤：

操作失敗：將SQL腳本應用於數據庫時出錯。 錯誤1005：無法創建表vipsouth_app 。 #sql-1f48_7 （錯誤號：150“外鍵約束#sql-1f48_7不正確”）

CREATE TABLE `inspection_responses` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `inspection_request_id` int(10) unsigned NOT NULL,
  `tpa_result` varchar(10) CHARACTER SET utf8 NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `created_by` int(10) unsigned NOT NULL DEFAULT '0',
  `updated_at` timestamp NULL DEFAULT NULL,
  `updated_by` int(10) unsigned DEFAULT NULL,
  `deleted_at` timestamp NULL DEFAULT NULL,
  `deleted_by` int(10) unsigned DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `id_UNIQUE` (`id`),
  UNIQUE KEY `tpa_result_UNIQUE` (`tpa_result`),
  KEY `inspection_responses_ibfk_1_idx` (`inspection_request_id`),
  CONSTRAINT `inspection_responses_ibfk_1` FOREIGN KEY (`inspection_request_id`) REFERENCES `inspection_requests` (`id`) ON DELETE     CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci

CREATE TABLE `inspection_statuses` (
  `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
  `inspection_request_id` int(10) unsigned NOT NULL,
  `inspection_response_id` int(10) unsigned NOT NULL,
  `tpa_code` varchar(4) COLLATE utf8_unicode_ci NOT NULL,
  `user_id` varchar(30) COLLATE utf8_unicode_ci NOT NULL,
  `password` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
  `inspection_id` varchar(10) COLLATE utf8_unicode_ci NOT NULL,
  `status` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL,
  `note` varchar(1000) COLLATE utf8_unicode_ci DEFAULT NULL,
  `url` varchar(1024) COLLATE utf8_unicode_ci DEFAULT NULL,
  `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
  `created_by` int(10) unsigned NOT NULL,
  `updated_at` timestamp NULL DEFAULT NULL,
  `updated_by` int(10) unsigned DEFAULT NULL,
  `deleted_at` timestamp NULL DEFAULT NULL,
  `deleted_by` int(10) unsigned DEFAULT NULL,
  PRIMARY KEY (`id`),
  UNIQUE KEY `id_UNIQUE` (`id`),
  KEY `inspection_statuses_ibfk_1_idx` (`inspection_request_id`),
  KEY `inspection_statuses_ibfk_2_idx` (`inspection_response_id`),
  CONSTRAINT `inspection_statuses_ibfk_1` FOREIGN KEY (`inspection_request_id`) REFERENCES `inspection_requests` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
  CONSTRAINT `inspection_statuses_ibfk_2` FOREIGN KEY (`inspection_response_id`) REFERENCES `inspection_responses` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci

Answer 1

在兩列上定義的數據類型和約束應完全相同。 除了外鍵可以為NULLable。

這應該為您做。 我沒有任何錯誤。

SET foreign_key_checks = 0;

    CREATE TABLE `inspection_responses` (
      `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
      `inspection_request_id` int(10) unsigned NOT NULL,
      `tpa_result` varchar(10) CHARACTER SET utf8 NOT NULL,
      `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
      `created_by` int(10) unsigned NOT NULL DEFAULT '0',
      `updated_at` timestamp NULL DEFAULT NULL,
      `updated_by` int(10) unsigned DEFAULT NULL,
      `deleted_at` timestamp NULL DEFAULT NULL,
      `deleted_by` int(10) unsigned DEFAULT NULL,
      PRIMARY KEY (`id`),
      UNIQUE KEY `id_UNIQUE` (`id`),
      UNIQUE KEY `tpa_result_UNIQUE` (`tpa_result`),
      KEY `inspection_responses_ibfk_1_idx` (`inspection_request_id`),
      CONSTRAINT `inspection_responses_ibfk_1` FOREIGN KEY (`inspection_request_id`) REFERENCES `inspection_requests` (`id`) ON DELETE     CASCADE ON UPDATE CASCADE
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

    CREATE TABLE `inspection_statuses` (
      `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
      `inspection_request_id` int(10) unsigned NOT NULL,
      `inspection_response_id` int(10) unsigned NOT NULL,
      `tpa_code` varchar(4) COLLATE utf8_unicode_ci NOT NULL,
      `user_id` varchar(30) COLLATE utf8_unicode_ci NOT NULL,
      `password` varchar(100) COLLATE utf8_unicode_ci NOT NULL,
      `inspection_id` varchar(10) COLLATE utf8_unicode_ci NOT NULL,
      `status` varchar(50) COLLATE utf8_unicode_ci DEFAULT NULL,
      `note` varchar(1000) COLLATE utf8_unicode_ci DEFAULT NULL,
      `url` varchar(1024) COLLATE utf8_unicode_ci DEFAULT NULL,
      `created_at` timestamp NOT NULL DEFAULT '0000-00-00 00:00:00',
      `created_by` int(10) unsigned NOT NULL,
      `updated_at` timestamp NULL DEFAULT NULL,
      `updated_by` int(10) unsigned DEFAULT NULL,
      `deleted_at` timestamp NULL DEFAULT NULL,
      `deleted_by` int(10) unsigned DEFAULT NULL,
      PRIMARY KEY (`id`),
      UNIQUE KEY `id_UNIQUE` (`id`),
      KEY `inspection_statuses_ibfk_1_idx` (`inspection_request_id`),
      KEY `inspection_statuses_ibfk_2_idx` (`inspection_response_id`),
      CONSTRAINT `inspection_statuses_ibfk_1` FOREIGN KEY (`inspection_request_id`) REFERENCES `inspection_requests` (`id`) ON DELETE CASCADE ON UPDATE CASCADE,
      CONSTRAINT `inspection_statuses_ibfk_2` FOREIGN KEY (`inspection_response_id`) REFERENCES `inspection_responses` (`id`) ON DELETE CASCADE ON UPDATE CASCADE
    ) ENGINE=InnoDB DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci;

SET foreign_key_checks = 1;