使用PHP更新多个字段（MySQL）

我需要将数据库（电话号码）中的字段更新为新格式。我可以使用mysqli来做到这一点，但是看到它贬值了，我想知道是否有人对使用mysqli更新多个字段有任何建议？数字格式化程序的数字代码为：

function formatPhoneNumber($phoneNumber) {
    $phoneNumber = preg_replace('/[^0-9]/','',$phoneNumber);

    if(strlen($phoneNumber) > 10) {
        $countryCode = substr($phoneNumber, 0, strlen($phoneNumber)-10);
        $areaCode = substr($phoneNumber, -10, 3);
        $nextThree = substr($phoneNumber, -7, 3);
        $lastFour = substr($phoneNumber, -4, 4);

        $phoneNumber = '+'.$countryCode.' ('.$areaCode.') '.$nextThree.'-'.$lastFour;
    }
    else if(strlen($phoneNumber) == 10) {
        $areaCode = substr($phoneNumber, 0, 3);
        $nextThree = substr($phoneNumber, 3, 3);
        $lastFour = substr($phoneNumber, 6, 4);

        $phoneNumber = '('.$areaCode.') '.$nextThree.'-'.$lastFour;
    }
    else if(strlen($phoneNumber) == 7) {
        $nextThree = substr($phoneNumber, 0, 3);
        $lastFour = substr($phoneNumber, 3, 4);

        $phoneNumber = $nextThree.'-'.$lastFour;
    }

    return $phoneNumber;
}

而查询将是SELECT customers_id, customers_telephone FROM customers WHERE customers_telephone NOT IN (' ')，将影响近20,000行，最有效的方法是什么？

for循环看起来像这样，但是它只是在做数组中的第一个客户：

foreach($customers as $row)
{
    $customer_id = $row['customers_id'];
    $numbers_array = $row['customers_telephone'];
    function formatPhoneNumber($phoneNumber) {
    $phoneNumber = preg_replace('/[^0-9]/','',$phoneNumber);

    if(strlen($phoneNumber) > 10) {
        $countryCode = substr($phoneNumber, 0, strlen($phoneNumber)-10);
        $areaCode = substr($phoneNumber, -10, 3);
        $nextThree = substr($phoneNumber, -7, 3);
        $lastFour = substr($phoneNumber, -4, 4);

        $phoneNumber = '+'.$countryCode.'-'.$areaCode.'- '.$nextThree.'-'.$lastFour;
    }
    else if(strlen($phoneNumber) == 10) {
        $areaCode = substr($phoneNumber, 0, 3);
        $nextThree = substr($phoneNumber, 3, 3);
        $lastFour = substr($phoneNumber, 6, 4);

        $phoneNumber = $areaCode.'- '.$nextThree.'-'.$lastFour;
    }
    else if(strlen($phoneNumber) == 7) {
        $nextThree = substr($phoneNumber, 0, 3);
        $lastFour = substr($phoneNumber, 3, 4);

        $phoneNumber = $nextThree.'-'.$lastFour;
    }

    return $phoneNumber;
}
    formatPhoneNumber($numbers_array);
    echo $numbers_array."  -  ".$customer_id;

}