【EC-CUBE3】指定した商品の過去一ヶ月の注文数を集計する方法

SampleController.php

<?php
namespace Plugin\Sample\Controller;

use Eccube\Application;
use Eccube\Common\Constant;
use Symfony\Component\HttpFoundation\Request;

class SampleController
{
	public function index(Application $app, Request $request)
	{
		$qb = $app['orm.em']->getRepository('Eccube\Entity\OrderDetail')
			->createQueryBuilder('od')
			->innerJoin('od.Product', 'p')
			->innerJoin('Eccube\Entity\Order', 'o', 'WITH', 'o.id = od.Order')
			->select('COUNT(p.id) AS orders')
			->groupBy('p.id')
			->where('o.order_date >= :now')
			->andWhere('p.id = :product_id')
			->setParameter('product_id', $app['request']->get('id'))
			->setParameter('now', new \DateTime('-1 month'));

		$result = $qb
 			->getQuery()
  			->getSingleResult();
  			
  		dump($result);
	}
}