Question

我正在尝试运行php artisan migrate以使用laravel创建我的mysql表。

我收到此错误：外键约束格式错误

用户表：

Schema::create('users', function (Blueprint $table) {
      $table->increments('id');
      $table->string('name');
      $table->string('email', 150)->unique();
      $table->timestamp('email_verified_at')->nullable();
      $table->string('password');
      $table->rememberToken();
      $table->timestamps();
 });

相册表：

Schema::create('albums', function (Blueprint $table) {
       $table->increments('id');
       $table->integer('user_id')->unsigned();
       $table->string('title');
       $table->text('description');
       $table->boolean('public');
       $table->foreign('user_id')->references('id')->on('users')-> 
       onDelete('SET NULL');
       $table->timestamps();
   });

图片表格：

Schema::create('images', function (Blueprint $table) {
       $table->increments('image_id');
       $table->integer('user_id')->unsigned();;
       $table->string('image');
       $table->integer('album_id')->unsigned();;
       $table->string('title');
       $table->string('description');
       $table->foreign('user_id')->references('id')->on('users')- >onDelete('SET NULL');
       $table->foreign('album_id')->references('id')->on('albums')->onDelete('SET NULL');
       $table->timestamps();
   });

但是有错误：

SQLSTATE[HY000]: General error: 1005 Can't create table `photo_storage`.`#sql-2d70_10a` (errno: 150 "Foreign key constraint is incorrectly formed") (SQL: alter table `albums` add constraint `albums_user_id_foreign` foreign key (`user_id`) references `users` (`id`) on delete SET NULL)`

Answer 1

因为您有->onDelete('SET NULL')，所以它期望字段user_id / album_id可为空。像这样将图像和相册表中的user_id和album_id设为可空 $this->integer('field')->nullable() 然后重试

'php artisan migration'如何解决错误“外键约束格式错误”？

1 个答案: