尽管预计至少有一行，但未找到查询结果

我有以下代码:

/**
     * Search similar category given a string
     * 
     * @param $searchTerm search similar category
     */
    public function findOneSimilarCategory($searchTerm)
    {
        $query = $this->createQueryBuilder('secondLevelCategory')
                ->select('secondLevelCategory')
                ->where('secondLevelCategory.categoryTitle LIKE :searchTerm')
                ->setParameter('searchTerm', $searchTerm)
                ->getQuery();

        $query->useResultCache(true, self::CACHE_RESULT_LIFETIME, md5(__METHOD__ . serialize('category-search-' . $query->getParameters())));
        $query->useQueryCache(true);
        return $query->getSingleResult();
    }

但是这给了我一个错误:

however this gives me an error:

"PHP 消息:PHP 致命错误:未捕获的异常 'DoctrineORMNoResultException'，消息为 '未找到查询结果，尽管预期至少有一行.'在/var/www/Shopious/vendor/doctrine/orm/lib/Doctrine/ORM/AbstractQuery.php:649

推荐答案

您收到此错误是因为您正在使用 getSingleResult() 方法.如果它甚至找不到单个结果，它就会生成一个异常.如果查询没有任何结果，您可以使用 getOneOrNullResult() 来代替获取 NULL.

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():检索单个对象.如果结果包含多个对象，则抛出 NonUniqueResultException.如果结果不包含对象，则抛出 NoResultException.纯/混合的区别不适用.

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.