为什么在区域表定义中未创建 state_id 字段？

Question

我尝试将旧数据库从 laravel 5.x 重构为 laravel 8 并拥有 2 个相关表： 数据库/迁移/2019_05_21_144910_create_states_table.php：

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;

class CreateStatesTable extends Migration {

   /**
    * Run the migrations.
    *
    * @return void
    */
   public function up()
   {
      Schema::create('states', function(Blueprint $table)
      {
            $table->smallIncrements('id')->unsigned();
            $table->string('code', 3)->unique();
         $table->string('name', 50)->unique();
         $table->string('slug', 55)->unique();
            $table->enum('active', ['A', 'I'])->default('I')->comment(' A=>Active, I=>Inactive');
         $table->index(['active','code'], 'fk_states_active_code_ixd');
         $table->index(['active','slug'], 'fk_states_active_slug_ixd');
      });
   }


   /**
    * Reverse the migrations.
    *
    * @return void
    */
   public function down()
   {
      Schema::drop('states');
   }

}

和数据库/迁移/2019_05_21_145001_create_regions_table.php：

<?php

use Illuminate\Database\Migrations\Migration;
use Illuminate\Database\Schema\Blueprint;

class CreateRegionsTable extends Migration
{

    /**
     * Run the migrations.
     *
     * @return void
     */
    public function up()
    {
        Schema::create('regions', function (Blueprint $table) {

            $table->smallIncrements('id')->unsigned();

            $table->foreign('state_id')->references('id')->on('states')->onUpdate('RESTRICT')->onDelete('RESTRICT');


            $table->string('name', 50);
            $table->string('slug', 55)->unique();

            $table->enum('active', ['A', 'I'])->default('I')->comment(' A=>Active, I=>Inactive');

            $table->unique(['state_id', 'name']);

            $table->index(['state_id', 'active'], 'fk_regions_state_id_active_ixd');
        });
    }


    /**
     * Reverse the migrations.
     *
     * @return void
     */
    public function down()
    {
        Schema::drop('regions');
    }

}

运行迁移命令时出错：

php artisan migrate:fresh --seed
...
Migrating: 2019_05_21_144910_create_states_table
Migrated:  2019_05_21_144910_create_states_table (626.91ms)
Migrating: 2019_05_21_145001_create_regions_table

   Illuminate\Database\QueryException 

  SQLSTATE[42000]: Syntax error or access violation: 1072 Key column 'state_id' doesn't exist in table (SQL: alter table `regions` add constraint `regions_state_id_foreign` foreign key (`state_id`) references `states` (`id`) on delete RESTRICT on update RESTRICT)

  at vendor/laravel/framework/src/Illuminate/Database/Connection.php:703
    699▕         // If an exception occurs when attempting to run a query, we'll format the error
    700▕         // message to include the bindings with SQL, which will make this exception a
    701▕         // lot more helpful to the developer instead of just the database's errors.
    702▕         catch (Exception $e) {
  ➜ 703▕             throw new QueryException(
    704▕                 $query, $this->prepareBindings($bindings), $e
    705▕             );
    706▕         }
    707▕     }

      +9 vendor frames 
  10  database/migrations/2019_05_21_145001_create_regions_table.php:31
      Illuminate\Support\Facades\Facade::__callStatic()

      +32 vendor frames 
  43  artisan:37
      Illuminate\Foundation\Console\Kernel::handle()

在区域表中，我有区域表，但没有 state_id 字段。看起来像线

$table->foreign('state_id')->references('id')->on('states')->onUpdate('RESTRICT')->onDelete('RESTRICT');

被忽略了，我无法理解为什么？试了好几次...

更新 2： 我将 CreateRegionsTable 修改为：

Schema::create('regions', function (Blueprint $table) {

    $table->smallIncrements('id')->unsigned();
   $table->foreignId('state_id')->constrained('states')->onUpdate('RESTRICT')->onDelete('RESTRICT');

但我遇到了其他错误：

  SQLSTATE[HY000]: General error: 3780 Referencing column 'state_id' and referenced column 'id' in foreign key constraint 'regions_state_id_foreign' are incompatible. (SQL: alter table `regions` add constraint `regions_state_id_foreign` foreign key (`state_id`) references `states` (`id`) on delete RESTRICT on update RESTRICT)

在 database/migrations/2019_05_21_144910_create_states_table.php 我有：

Schema::create('states', function(Blueprint $table)
{
    $table->smallIncrements('id')->unsigned();

我认为 foreignId 与 smallIncrements 不兼容...但哪种方法有效？

提前致谢！

Answer 1

$table->foreign() 方法仅将外键约束添加到现有列。你要找的方法是$table->foreignId()

所以而不是

$table->foreign('state_id')->references('id')->on('states')->onUpdate('RESTRICT')->onDelete('RESTRICT');

在您的区域表迁移中，您应该这样做

$table->foreignId('state_id')->constrained('states')->onUpdate('RESTRICT')->onDelete('RESTRICT');

documentation