```php
<?php

require_once '../../core/api_bootstrap.php';
require_once '../../services/crud_service.php';

$data=Request::post();

Validator::required($data,['id','city_id','pincode']);

$db=new Database();
$conn=$db->connect();

$crud=new CrudService($conn);

$crud->update('pincodes',[
'city_id'=>$data['city_id'],
'pincode'=>$data['pincode'],
'area_name'=>$data['area_name'] ?? null,
'status'=>$data['status'] ?? 1
],$data['id']);

Response::success([],"Pincode updated");