autocde2.0/app/Http/Resources/API/DepartmentResource.php

<?php
/**
 * Created by IntelliJ IDEA.
 * User: kelyliang
 * Date: 2024/2/29
 * Time: 上午 11:46
 */

namespace App\Http\Resources\API;

use Illuminate\Http\Request;
use Illuminate\Http\Resources\Json\JsonResource;

class DepartmentResource extends JsonResource
{
    public function toArray(Request $request): array
    {
        return[
          'id' => $this->id,
          'name' => $this->name,
          'parent_id'  => $this->parent_id,
          'children' => $this->parent_id == 0 ? DepartmentResource::collection($this->children) : [],
        ];
    }
}