deleteDataFromOxidShop.php

<?php
//WARNING: this file deletes content from DB! be careful!
// Use this in a oxid e-sales shop 4.7.0 or higher
//if you are aware of the risks, remove or comment the next line:
die('Please read the comments!');
include('bootstrap.php');
$aDeletes = array(
    'oxcategory',
    'oxvendor',
    'oxmanufacturer',
    'oxattribute',
    'oxarticle',
    'oxselectlist',
);
foreach ($aDeletes AS $class) {
    /** @var oxBase $oEntity */
    $oEntity = oxNew($class);
    $aOxIds  = oxDB::getDb(oxDb::FETCH_MODE_ASSOC)->getAll("SELECT oxid FROM {$oEntity->getCoreTableName()}");
    foreach ($aOxIds as $sId) {
        $oEntity->delete($sId['oxid']);
    }
    echo $oEntity->getClassName() . ': ' . count($aOxIds) . PHP_EOL;
}

So, pull requests are not available for gist...
I would like you to review and merge the changes i have made in my fork of this gist.

Thankyou @KatoPue for your suggestion, I take over your changes.