sam-api/app/Models/Products/PriceRevision.php

<?php

namespace App\Models\Products;

use App\Models\User;
use App\Traits\Auditable;
use App\Traits\BelongsToTenant;
use Illuminate\Database\Eloquent\Model;
use Illuminate\Database\Eloquent\Relations\BelongsTo;

class PriceRevision extends Model
{
    use Auditable, BelongsToTenant;

    protected $table = 'price_revisions';

    /**
     * created_at만 사용 (updated_at 없음)
     */
    public const UPDATED_AT = null;

    protected $fillable = [
        'tenant_id',
        'price_id',
        'revision_number',
        'changed_at',
        'changed_by',
        'change_reason',
        'before_snapshot',
        'after_snapshot',
    ];

    protected $casts = [
        'price_id' => 'integer',
        'revision_number' => 'integer',
        'changed_at' => 'datetime',
        'changed_by' => 'integer',
        'before_snapshot' => 'array',
        'after_snapshot' => 'array',
    ];

    // ─────────────────────────────────────────────────────────────
    // Relations
    // ─────────────────────────────────────────────────────────────

    /**
     * 단가 관계
     */
    public function price(): BelongsTo
    {
        return $this->belongsTo(Price::class, 'price_id');
    }

    /**
     * 변경자 관계
     */
    public function changedByUser(): BelongsTo
    {
        return $this->belongsTo(User::class, 'changed_by');
    }
}