Laravel 在通过 ssh 使用 migration:fresh 时显示 1215（无法添加外键约束）

Question

Laravel 5.6.38

MySQL 5.7.23

PHP v7.2.10

在 localhost PHP 7.2.4 中，它在 localhost 中工作正常，但在生产中它显示以下错误。

php artisan migrate:fresh
Dropped all tables successfully.
Migration table created successfully.

   Illuminate\Database\QueryException  : SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint (SQL: alter table `videos` add constraint `videos_video_status_id_foreign` foreign key (`video_status_id`) references `statuses` (`status_id`))

  at /var/www/html/myapp/vendor/laravel/framework/src/Illuminate/Database/Connection.php:664
    660|         // If an exception occurs when attempting to run a query, we'll format the error
    661|         // message to include the bindings with SQL, which will make this exception a
    662|         // lot more helpful to the developer instead of just the database's errors.
    663|         catch (Exception $e) {
  > 664|             throw new QueryException(
    665|                 $query, $this->prepareBindings($bindings), $e
    666|             );
    667|         }
    668|

  Exception trace:

  1   PDOException::("SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint")
      /var/www/html/myapp/vendor/laravel/framework/src/Illuminate/Database/Connection.php:458

  2   PDOStatement::execute()
      /var/www/html/myapp/vendor/laravel/framework/src/Illuminate/Database/Connection.php:458

  Please use the argument -v to see more details.

本地主机运行是这样的

D:\work\www\myapp>php artisan migrate:fresh
Dropped all tables successfully.
Migration table created successfully.
Migrating: 2014_10_12_000000_create_users_table
Migrated:  2014_10_12_000000_create_users_table
Migrating: 2014_10_12_100000_create_password_resets_table
Migrated:  2014_10_12_100000_create_password_resets_table
Migrating: 2018_08_29_112331_entrust_setup_tables
Migrated:  2018_08_29_112331_entrust_setup_tables
Migrating: 2018_08_31_103313_create_audits_table
Migrated:  2018_08_31_103313_create_audits_table
Migrating: 2018_09_06_125909_create_videos_table
Migrated:  2018_09_06_125909_create_videos_table
Migrating: 2018_09_12_064922_create_labels_table
Migrated:  2018_09_12_064922_create_labels_table
Migrating: 2018_09_14_073215_create_statuses_table
Migrated:  2018_09_14_073215_create_statuses_table
Migrating: 2018_09_14_114329_create_video_taggings_table
Migrated:  2018_09_14_114329_create_video_taggings_table
Migrating: 2018_09_15_105623_create_priorities_table
Migrated:  2018_09_15_105623_create_priorities_table
Migrating: 2018_09_17_044820_create_comments_table
Migrated:  2018_09_17_044820_create_comments_table
Migrating: 2018_09_24_130041_create_video_tagging_q_as_table
Migrated:  2018_09_24_130041_create_video_tagging_q_as_table

与@apokryfos讨论后更新

现在迁移文件是

2014_10_12_000000_create_users_table
2014_10_12_100000_create_password_resets_table
2018_08_29_112331_entrust_setup_tables
2018_08_31_103313_create_audits_table
2018_09_06_064922_create_labels_table
2018_09_06_073215_create_statuses_table
2018_09_06_105623_create_priorities_table
2018_09_06_125909_create_videos_table
2018_09_14_114329_create_video_taggings_table
2018_09_17_044820_create_comments_table
2018_09_24_130041_create_video_tagging_q_as_table

我收到错误消息

Dropped all tables successfully.
Migration table created successfully.

   Illuminate\Database\QueryException  : SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint (SQL: alter table `videos` add constraint `videos_video_identified_by_foreign` foreign key (`video_identified_by`) references `users` (`id`))

  at D:\work\www\myapp\vendor\laravel\framework\src\Illuminate\Database\Connection.php:664
    660|         // If an exception occurs when attempting to run a query, we'll format the error
    661|         // message to include the bindings with SQL, which will make this exception a
    662|         // lot more helpful to the developer instead of just the database's errors.
    663|         catch (Exception $e) {
  > 664|             throw new QueryException(
    665|                 $query, $this->prepareBindings($bindings), $e
    666|             );
    667|         }
    668|

  Exception trace:

  1   PDOException::("SQLSTATE[HY000]: General error: 1215 Cannot add foreign key constraint")
      D:\work\www\myapp\vendor\laravel\framework\src\Illuminate\Database\Connection.php:458

  2   PDOStatement::execute()
      D:\work\www\myapp\vendor\laravel\framework\src\Illuminate\Database\Connection.php:458

所以，问题不在于创建迁移文件的日期，它似乎有所不同。

请使用参数-v查看更多详情。

Answer 1

我解决了一些方法，但我想承认，每个人都应该非常严格地使用Laravel迁移。

哪里出错了？

我在 localhost 上工作，所以在开发过程中，你需要对你的 table 结构进行大量更改，并且在此过程中我还需要重新生成 tables 很多时间，所以我想法是，我不需要为每个修改创建另一个迁移文件，因为我现在正在重新生成所有内容，当应用程序完成并且我需要进行更改时，那时我将使用单独的迁移文件。

有什么问题吗？

Laravel 正在根据迁移文件创建日期创建 tables，它永远不会使用您的文件更新 :P，因此当一个 table 创建并需要外键时来自另一个尚未创建的 table，它会产生此错误。

因此，如果您的 FK 指向 PK，请确保源列存在。

如何解决？

调整迁移文件的生成顺序。按顺序生成新文件，复制内容，删除乱序的旧文件。

这绝不是一个好主意，所以请严格遵守规则。

Laravel 在通过 ssh 使用 migration:fresh 时显示 1215（无法添加外键约束）

Laravel showing 1215(Cannot add foreign key constraint) when using migration:fresh through ssh

php

laravel-migrations

laravel-5.6