eCert-MBIP/app/Models/ProgramQuestionnaire.php

<?php

namespace App\Models;

use Illuminate\Database\Eloquent\Model;

class ProgramQuestionnaire extends Model
{
    protected $fillable = [
        'program_id', 'questionnaire_set_id', 'is_confirmed', 'confirmed_at', 'confirmed_by',
    ];

    protected function casts(): array
    {
        return [
            'is_confirmed' => 'boolean',
            'confirmed_at' => 'datetime',
        ];
    }

    public function program()
    {
        return $this->belongsTo(Program::class);
    }

    public function questionnaireSet()
    {
        return $this->belongsTo(QuestionnaireSet::class);
    }

    public function confirmedBy()
    {
        return $this->belongsTo(User::class, 'confirmed_by');
    }
}