doctrine - 用 Twig 展示 Doctrine 集？ (Symfony2)

Question

我有一个非常简单的代表新闻的 Doctrine 实体；这个新闻可以与很多图片联系起来，所以我决定使用 Doctrine 集。问题是，我想检索这些图片并将它们显示在我的模板中......但它似乎不起作用。你知道我该怎么做吗？

这是我尝试过的:

{% for annonce in annonces %}
    <div class="annonce_item">
    {% for photo in annonce.photo  %}
        <img src="{{ photo.path }}" alt="" />
    {% endfor %}
</div>
<!-- End .annonce_item -->
{% endfor %}

annonce 是新闻类，photo 是集合:

/**
 * @ORM\OneToMany(targetEntity="Photo", mappedBy="id",cascade={"persist"})
 */

private $photo;

当我尝试在浏览器中显示此页面时，出现以下异常:

An exception has been thrown during the rendering of a template ("Notice: Undefined index: >id in >/Applications/MAMP/htdocs/ApacheImmobilier/vendor/doctrine/lib/Doctrine/ORM/Persisters/Basi>cEntityPersister.php line 1274") in "APPagesBundle:Index:index.html.twig" at line 45.

谢谢!

Answer 1

阅读this article of the doc 。它说:

The mappedBy attribute designates the field in the entity that is the owner of the relationship.

在您的情况下，它必须是您的照片实体的 news 字段。