spa-api/app/Models/CategoryModel.php

<?php

namespace App\Models;

use App\BaseApp\BaseModel;
use Illuminate\Database\Eloquent\Relations\HasMany;

/**
 * 分类表
 */
class CategoryModel extends BaseModel
{
    //
    protected $table = 'categories';

    protected $guarded  = [];

    /**
     * 项目
     * @return HasMany
     */
    public function projects(): HasMany
    {
        return $this->hasMany(ProjectModel::class, 'category_id', 'id');
    }
}