<?php use MapGuesser\PersistentData\Model\User; use MapGuesser\Repository\UserRepository; use MapGuesser\Util\UsernameGenerator; use SokoWeb\Database\Query\Select; $select = new Select(Container::$dbConnection); $users = Container::$persistentDataManager->selectMultipleFromDb($select, User::class); $userRepository = new UserRepository(); $usernameGenerator = new UsernameGenerator(); foreach ($users as $user) { do { $username = $usernameGenerator->generate(); } while ($userRepository->getByUsername($username)); $user->setUsername($username); Container::$persistentDataManager->saveToDb($user); }