Question

我想在种子之前截断我的用户表。我这样做：

DatabaseSeeder.php：

 <?php

 use Illuminate\Database\Seeder;
 use Illuminate\Support\Facades\DB;

 class DatabaseSeeder extends Seeder
 {
     public function run()
     {
         App\User::truncate();

         factory(App\User::class,1)->create();
     }
 }

然后运行 php artisan db:seed 并出现错误：

In Connection.php line 664:

  SQLSTATE[42000]: Syntax error or access violation: 1701 Cannot truncate a table referenced in a foreign key constra
  int (`mr_musicer`.`dislikes`, CONSTRAINT `dislikes_user_id_foreign` FOREIGN KEY (`user_id`) REFERENCES `mr_musicer`
  .`users` (`id`)) (SQL: truncate `users`)


In Connection.php line 458:

  SQLSTATE[42000]: Syntax error or access violation: 1701 Cannot truncate a table referenced in a foreign key constra
  int (`mr_musicer`.`dislikes`, CONSTRAINT `dislikes_user_id_foreign` FOREIGN KEY (`user_id`) REFERENCES `mr_musicer`
  .`users` (`id`))

我现在想为什么我不能截断用户表！

Answer 1

存在外键问题，表格正试图提醒您。如果仍然要截断表。

    Schema::disableForeignKeyConstraints();

    // ... Some Truncate Query

    Schema::enableForeignKeyConstraints();

别忘了使用： use Illuminate\Support\Facades\Schema;

Answer 2

您在其他一些表上都引用了您的用户。您应该将->onDelete('cascade')添加到引用用户ID的“不喜欢”表列中，或者首先手动删除所有不喜欢的人。

$table->foreign('user_id')->references('id')->on('users')->onDelete('cascade');

Answer 3

播种前截断数据的最简单方法

只需在 run 方法的开头添加这一行即可。

DB::table('users')->truncate();

run 方法的完整语法

namespace Database\Seeders;

use Illuminate\Database\Seeder;
use Illuminate\Support\Facades\DB;
use Illuminate\Support\Facades\Hash;

class AdminSeeder extends Seeder
{
    /**
     * Run the database seeds.
     *
     * @return void
     */
    public function run()
    {
        DB::table('users')->truncate();
        DB::table('users')->insert([
            'name' => 'Admin',
            'email' => 'admin@example.com',
            'is_admin' => 1,
            'password' => Hash::make('password'),
        ]);
    }
}

无法在播种前截断表

3 个答案: