Laravelのphp artisan migrate:refreshを行ったときのエラー

前提・実現したいこと

Laravelでアプリケーションを開発中、php artisan migrate:refreshにおいてエラーが発生しました

発生している問題・エラーメッセージ

エラーメッセージ
Rolling back: 2014_10_12_000000_create_users_table

   Illuminate\Database\QueryException 

  SQLSTATE[23000]: Integrity constraint violation: 1217 Cannot delete or update a parent row: a foreign key constraint fails (SQL: drop table if exists `users`)

  at vendor/laravel/framework/src/Illuminate/Database/Connection.php:671
    667|         // If an exception occurs when attempting to run a query, we'll format the error
    668|         // message to include the bindings with SQL, which will make this exception a
    669|         // lot more helpful to the developer instead of just the database's errors.
    670|         catch (Exception $e) {
  > 671|             throw new QueryException(
    672|                 $query, $this->prepareBindings($bindings), $e
    673|             );
    674|         }
    675| 

      +9 vendor frames 
  10  database/migrations/2014_10_12_000000_create_users_table.php:34
      Illuminate\Support\Facades\Facade::__callStatic("dropIfExists")

      +34 vendor frames 
  45  artisan:37
      Illuminate\Foundation\Console\Kernel::handle(Object(Symfony\Component\Console\Input\ArgvInput), Object(Symfony\Component\Console\Output\ConsoleOutput))

該当のソースコード

Laravel
1ソースコード
2<?php
3
4use Illuminate\Database\Migrations\Migration;
5use Illuminate\Database\Schema\Blueprint;
6use Illuminate\Support\Facades\Schema;
7
8class CreateAppTables extends Migration
9{
10    /**
11     * Run the migrations.
12     *
13     * @return void
14     */
15    public function up()
16    {
17        Schema::create('item_conditions', function (Blueprint $table) {
18            $table->id();
19
20            $table->timestamps();
21        });
22
23        Schema::create('primary_categories', function (Blueprint $table) {
24            $table->id();
25
26            $table->timestamps();
27        });
28
29        Schema::create('secondary_categories', function (Blueprint $table) {
30            $table->id();
31            $table->unsignedBigInteger('primary_id');
32
33            $table->timestamps();
34
35            $table->foreign('primary_category_id')->references('id')->on('primary_categories');
36        });
37
38        //itemsテーブル
39        Schema::create('items', function (Blueprint $table) {
40            $table->id();
41            $table->unsignedBigInteger('seller_id');
42            $table->unsignedBigInteger('buyer_id');
43            $table->unsignedBigInteger('item_condition_id');
44            $table->unsignedBigInteger('secondary_category_id');
45
46            $table->timestamps();
47
48            $table->foreign('seller_id')->references('id')->on('users');
49            $table->foreign('buyer_id')->references('id')->on('users');
50            $table->foreign('item_condition_id')->references('id')->on('item_conditions');
51            $table->foreign('secondary_category_id')->references('id')->on('secondary_categorieså');
52        });
53        
54    }
55
56    /**
57     * Reverse the migrations.
58     *
59     * @return void
60     */
61    public function down()
62    {
63        Schema::dropIfExists('items');
64        Schema::dropIfExists('item_conditions');
65        Schema::dropIfExists('secondary_categories');
66        Schema::dropIfExists('primary_categories');
67    }
68}