Create Slugs in large MYSQL tables

create-slugs.php

<?php
// This script must be run on a command line

error_reporting(E_ALL);
set_time_limit(1200);
date_default_timezone_set("Europe/Amsterdam");

$mysqli = new mysqli('localhost', 'username', 'password', 'table');

if ($mysqli->connect_error) {
    die('Error : ('. $mysqli->connect_errno .') '. $mysqli->connect_error);
}

print_r('Progressing...');

$res = $mysqli->query('SELECT id, name FROM companies WHERE slug is NULL');

print_r($res);

while($obj = $res->fetch_object()){
        $slug = iconv('utf-8', 'us-ascii//TRANSLIT', $obj->name);
        $slug = strtolower(preg_replace('/[^A-Za-z0-9-]+/', '-', $slug));
        $slug = trim($slug, '-'); // Remove the last - if applicable
        $mysqli->query('UPDATE companies SET slug="'.$slug.'" WHERE id = '.$obj->id.'');
}

$res->free(); // Free the memory

$mysqli->close(); // Close the connection

?>