How to Find and Count Orphaned WooCommerce Product Variations

<?php

// This snippet should only run in "Manual" mode.

global $wpdb;

$orphaned_variations_results = $wpdb->get_results("SELECT * FROM {$wpdb->posts} o LEFT OUTER JOIN {$wpdb->posts} r ON o.post_parent = r.ID WHERE r.id IS null AND o.post_type = 'product_variation'");

$ov_count = count($orphaned_variations_results);

echo "There are $ov_count variations on your site.";