<?php

use RVR\PersistentData\Model\Community;
use SokoWeb\Database\Query\Select;

$select = new Select(Container::$dbConnection);
$communities = Container::$persistentDataManager->selectMultipleFromDb($select, Community::class);

foreach ($communities as $community) {
    $community->generateSlug();
    Container::$persistentDataManager->saveToDb($community);
}