SiteTable::checkUniqueInDomain

static function checkUniqueInDomain($code, $currentId, $domainId)
{
	$res = self::getList(array(
		'select' => array(
			'ID'
		),
		'filter' => array(
			'!ID' => $currentId,
			'DOMAIN_ID' => $domainId,
			'=CODE' => $code,
			'=DELETED' => ['Y', 'N'],
			'CHECK_PERMISSIONS' => 'N'
		)
	));
	return $res->fetch() ? false : true;
}