exchange-2.0/app/Models/Document.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\SoftDeletes;

use Illuminate\Database\Eloquent\Relations\hasMany;

/**
 * Class Document
 * @package App\Models
 * @version August 4, 2020, 4:36 am
 *
 * @property int owner_id
 * @property int owner_type
 * @property int document_type
 * @property string reference
 * @property int status
 * @property \App\Models\User approved_by
 * @property timestamp issued_date
 * @property timestamp expired_date
 * @property timestamp approved_date
 */
class Document extends AbstractModel
{
    use SoftDeletes;

    protected $table = 'documents';

    protected $dates = ['deleted_at'];

    /**
     * @return hasMany
     */
    public function files(): hasMany 
    {
        return $this->hasMany(File::class, 'document_id');
    }

}