mysql - "No result was found for query although at least one row was expected."查询应该在 Symfony 中显示记录

Question

我正在尝试使用 URL 中的两个项目来检索内容。这是应该执行此操作的 php/symfony 代码:

    $em = $this->getDoctrine()->getEntityManager();

    $repository = $this->getDoctrine()
        ->getRepository('ShoutMainBundle:Content');

    $query = $repository->createQueryBuilder('p')
        ->where('p.slug > :slug')
        ->andWhere('p.subtocontentid > :parent')
        ->setParameters(array(
                    'slug' => $slug,
                    'parent'  => $page
                ))
        ->getQuery();

    $content = $query->getSingleResult();

但是，当执行此代码时，它会返回以下错误:

No result was found for query although at least one row was expected.

我做了一些测试，$slug 和 $page 变量中保存的数据保存了正确的信息。我还测试了 MySQL 查询，查询显示了所需的结果，这让我更加困惑。

我错过了什么吗？

Answer 1

正如回答here

You are getting this error because you are using the getSingleResult() method. it generates an Exception if it can't find even a single result. you can use the getOneOrNullResult() instead to get a NULL if there isn't any result from the query.

Query#getSingleResult(): Retrieves a single object. If the result contains more than one object, an NonUniqueResultException is thrown. If the result contains no objects, an NoResultException is thrown. The pure/mixed distinction does not apply.