mysql add constraint - #1005 - Can't create table ... errno: 121 Duplicate key on write or update

Question

我一直在拉我的头发，我确信这是我看不到的小东西......

这是我的 2 个表公司和具有多对多关系的人员以及我的数据透视表 company_people：

CREATE TABLE `companies` (
  `id` bigint UNSIGNED NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `is_active` int NOT NULL DEFAULT '1',
  `company` varchar(120) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

CREATE TABLE `peoples` (
  `id` bigint UNSIGNED NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `is_active` int NOT NULL DEFAULT '1',
  `firstname` varchar(120) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci NOT NULL DEFAULT '',
  `lastname` varchar(120) CHARACTER SET utf8mb4 COLLATE utf8mb4_unicode_ci DEFAULT '',
  `company_id` bigint UNSIGNED DEFAULT '0'
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci PACK_KEYS=0;

CREATE TABLE `company_people` (
  `id` bigint NOT NULL,
  `created_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `updated_at` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  `company_id` bigint UNSIGNED NOT NULL,
  `people_id` bigint UNSIGNED NOT NULL
) ENGINE=InnoDB DEFAULT CHARSET=utf8mb4 COLLATE=utf8mb4_unicode_ci;

ALTER TABLE `companies`
  ADD PRIMARY KEY (`id`);

ALTER TABLE `peoples`
  ADD PRIMARY KEY (`id`),
  ADD KEY `company_id` (`company_id`);

ALTER TABLE `company_people`
  ADD PRIMARY KEY (`id`),
  ADD KEY `company_id` (`company_id`),
  ADD KEY `people_id` (`people_id`);

ALTER TABLE `companies`
  MODIFY `id` bigint UNSIGNED NOT NULL AUTO_INCREMENT;

ALTER TABLE `peoples`
  MODIFY `id` bigint UNSIGNED NOT NULL AUTO_INCREMENT;

ALTER TABLE `company_people`
  MODIFY `id` bigint NOT NULL AUTO_INCREMENT;

ALTER TABLE `peoples`
  ADD CONSTRAINT `peoples-company` FOREIGN KEY (`company_id`) REFERENCES `companies` (`id`) ON DELETE CASCADE ON UPDATE CASCADE;

ALTER TABLE `company_people`
  ADD CONSTRAINT `companies-peoples` FOREIGN KEY (`company_id`) REFERENCES `companies` (`id`) ON DELETE CASCADE ON UPDATE CASCADE;
ALTER TABLE `company_people`
  ADD CONSTRAINT `peoples-companies` FOREIGN KEY (`people_id`) REFERENCES `peoples` (`id`) ON DELETE CASCADE ON UPDATE CASCADE;

除了最后一个给出以下错误的 mysql 语句外，一切正常：#1005 - 无法创建表 FairTrade.company_people (errno: 121 "Duplicate key on write or update")

故障在哪里？

Answer 1

你有一个错误

ALTER TABLE `companies`
  ADD PRIMARY KEY (`id`),
  ADD KEY `company_id` (`company_id`);

明白了

错误代码：1072。表中不存在键列“company_id”

所以删除像这样的键

ALTER TABLE `companies`
  ADD PRIMARY KEY (`id`)
  ;

或选择另一列