Answers for "laravel 9 migration nullable foregn key"

foreign key nullable in laravel

$table
      ->foreignId('other_table_id')
      ->nullable() // here
      ->references('id')
      ->on('other_table');

laravel 8 foreign key migration

use Illuminate\Database\Schema\Blueprint;
use Illuminate\Support\Facades\Schema;

Schema::table('posts', function (Blueprint $table) {
    $table->unsignedBigInteger('user_id');

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