inanzzz | Handling batch data processing with doctrine iterate() function

If you're doing a batch-processing job such as batch-update, batch-delete, list then make sure you're using Query#iterate() in your QueryBuilder to avoid loading the whole result into memory at once. For more info, click here. Example below does batch-update.

Repository

use Doctrine\ORM\Internal\Hydration\IterableResult;

class UserProductRepository extends EntityRepository
{
    /**
     * @return IterableResult
     **/
    public function findProductsByUserIdAndProductNames($userId, array $productNames = [])
    {
        $dql = "SELECT up
                FROM Application\ProductBundle\Entity\UserProduct up
                WHERE up.user = :userId AND up.productName IN (:productNames)";
                
        return $this->getEntityManager()
            ->createQuery($dql)
            ->setParameters(['userId' => $userId, 'productNames' => $productNames])
            ->iterate();
    }
}

Service

use Doctrine\ORM\Internal\Hydration\IterableResult;

class UserProductService
{
    ...
    ...
    
    public function getUserProducts()
    {
        $userId = 123;
        $productNames = ['sony', 'samsung', 'htc'];
        
        $userProducts = $this->userProductRepository->findProductsByUserIdAndProductNames(
            $userId,
            productNames
        );
        
        if (count($userProducts)) {
            $batchSize = 20;
            foreach ($userProducts as $userProduct) {
                $userProduct[0]->setSell(new DateTime());
                
                --$batchSize;
                if ($batchSize === 0) {
                    $this->em->flush();
                    $this->em->clear();
                    $batchSize = 20;
                }
            }
            
            $this->em->flush();
            $this->em->clear();
        }
    }
}