Laravel 创建索引时，不相关字段上的datetime错误

我有一个带有locations表的数据库，该表包含表示给定位置地址的字符串字段-第一行、邮政编码、城市（该表使用

时间戳

和

软删除

）。我现在正在创建一个cities表，其中give location将通过外键连接到city

此迁移的架构表示为：

Schema::create('cities', function (Blueprint $table) {
    $table->increments('id');
    $table->string('title');
    $table->timestamps();
    $table->softDeletes();
});

Schema::table('locations', function ($table) {
    $table->integer('city_id')->unsigned()->nullable();
    $table->foreign('city_id')->references('id')->on('cities');
});

不幸的是，这给了我以下错误：

Invalid datetime format: 1292 Incorrect datetime value: '0000-00-00 00:00:00' for column 'deleted_
  at' at row 154 (SQL: alter table `locations` add constraint `locations_city_id_foreign` foreign key (`city_id`) ref
  erences `cities` (`id`))

现在，有一种简单的方法可以解决这个问题，在创建城市表和创建索引之间运行以下命令：

DB::table('locations')->where('deleted_at', "0000-00-00 00:00:00")->update([
    'deleted_at' => Carbon::now()
]);

问题是-为什么在不相关列上创建索引时会检查已删除列上的值

---

根据注释此处的当前输出

显示创建表位置
：

CREATE TABLE `locations` (
 `id` int(10) unsigned NOT NULL AUTO_INCREMENT,
 `token` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `external_id` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `is_pickup_choice` tinyint(1) DEFAULT '0',
 `title` varchar(255) COLLATE utf8_unicode_ci NOT NULL,
 `address_line_1` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `address_line_2` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `town` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `county` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `postcode` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `country` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `longitude` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `latitude` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `type_of_address` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `is_pickup` tinyint(1) DEFAULT '0',
 `is_dropoff` tinyint(1) DEFAULT '0',
 `is_live` tinyint(1) DEFAULT '0',
 `is_actual_point` tinyint(1) DEFAULT '0',
 `created_at` timestamp NULL DEFAULT NULL,
 `updated_at` timestamp NULL DEFAULT NULL,
 `deleted_at` timestamp NULL DEFAULT NULL,
 `is_near_public_transport` tinyint(1) DEFAULT '0',
 `public_transport_notes` longtext COLLATE utf8_unicode_ci,
 `notes` longtext COLLATE utf8_unicode_ci,
 `url` varchar(255) COLLATE utf8_unicode_ci DEFAULT NULL,
 `is_fictional` tinyint(1) DEFAULT '0',
 `city_id` int(10) unsigned DEFAULT NULL,
 PRIMARY KEY (`id`),
 KEY `locations_latitude_index` (`latitude`),
 KEY `locations_longitude_index` (`longitude`),
 KEY `locations_deleted_at_index` (`deleted_at`),
 KEY `locations_city_id_foreign` (`city_id`),
 CONSTRAINT `locations_city_id_foreign` FOREIGN KEY (`city_id`) REFERENCES `cities` (`id`)
) ENGINE=InnoDB AUTO_INCREMENT=8440 DEFAULT CHARSET=utf8 COLLATE=utf8_unicode_ci

这些都是在一个迁移文件中完成的吗？是的………位置表的迁移是什么样子的？添加了
SHOW CREATE table