php - Doctrine 和 Symfony2 : How to execute raw queries (General error: 2014 Cannot execute queries while > other unbuffered queries are active)

Question

我正在尝试使用 Doctrine 在 Symfony 框架中执行原始查询。

这是代码:

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);
    }

我已将 MessagesHandler 类设置为服务:

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

现在，当我执行代码时，我收到以下错误:

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.")...

如何使用 PDOStatement::fetchAll()？

Answer 1

使用createNativeQuery方法:

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

$count = $query->getResult();

此处提供文档:http://doctrine-orm.readthedocs.org/en/latest/reference/native-sql.html