public function activatePlugin()
 {
     $builder = new DbBuilder();
     $builder->dbInitialisation();
 }
<?php

// If uninstall is not called from WordPress, exit
if (!defined('WP_UNINSTALL_PLUGIN')) {
    exit;
}
require_once plugin_dir_path(__FILE__) . 'includes/DbBuilder.php';
$dbBuilder = new DbBuilder();
$dbBuilder->destroyAll();