Doctrine和Symfony2：如何执行原始查询（常规错误：2014在其他未缓冲的查询处于活动状态时无法执行查询）

Question

I'm trying to execute a raw query using Doctrine into the Symfony framework.

Here there is the code:

class MessagesHandler
{
    /** @var \Doctrine\Common\Persistence\ObjectManager The entity manager used to access entities */
    protected $em = null;

    public function __construct($em)
    {
        $this->em = $em;
    }

    public function getMessagesToPost($user)
    {
        $query = 'SELECT COUNT(*) FROM `messages` WHERE `posted_by` = ' . $user->getId() . ' AND `message_posted` = 0';

        return $this->em->getConnection()->exec($query);
    }

I have set the class MessagesHandler as a service:

services:
    shq.handler.Messages:
                class: AppBundle\Handler\MessagesHandler
                arguments: ["@doctrine.orm.entity_manager"]

Now, when I execute the code, I receive the following error:

SQLSTATE[HY000]: General error: 2014 Cannot execute queries while other unbuffered queries are active. Consider using PDOStatement::fetchAll(). Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.")...

How can I use PDOStatement::fetchAll()?

Answer 1

Use the createNativeQuery method:

$query = $entityManager->createNativeQuery('SELECT COUNT(*) FROM `messages` WHERE `posted_by` = ? AND `message_posted` = 0', $rsm);
$query->setParameter(1, $user->getId());

$count = $query->getResult();

Documentation available here: http://doctrine-orm.readthedocs.org/en/latest/reference/native-sql.html