如何阻止 Doctrine 2 在 Symfony 2 中缓存结果? [英] How to stop Doctrine 2 from caching a result in Symfony 2?

问题描述

我希望能够检索实体的现有版本，以便将其与最新版本进行比较.例如.编辑一个文件，我想知道自从在数据库中后该值是否发生了变化.

I want to be able to retrieve the existing version of an entity so I can compare it with the latest version. E.g. Editing a file, I want to know if the value has changed since being in the DB.

    $entityManager = $this->get('doctrine')->getEntityManager();
    $postManager = $this->get('synth_knowledge_share.manager');

    $repository = $entityManager->getRepository('KnowledgeShareBundle:Post');
    $post = $repository->findOneById(1); 

    var_dump($post->getTitle()); // This would output "My Title"
    $post->setTitle("Unpersisted new title");

    $existingPost = $repository->findOneById(1); // Retrieve the old entity

    var_dump($existingPost->getTitle()); // This would output "Unpersisted new title" instead of the expected "My Title"

有谁知道我如何解决这个缓存问题?

Does anyone know how I can get around this caching?

推荐答案

这是正常现象.

Doctrine 将检索到的实体的引用存储在 EntityManager 中，因此它可以通过其 id 返回实体，而无需执行其他查询.

Doctrine stores a reference of the retrieved entities in the EntityManager so it can return an entity by it's id without performing another query.

你可以这样做:

$entityManager = $this->get('doctrine')->getEntityManager();
$repository = $entityManager->getRepository('KnowledgeShareBundle:Post');
$post = $repository->find(1);

$entityManager->detach($post);

// as the previously loaded post was detached, it loads a new one
$existingPost = $repository->find(1);

但请注意，由于 $post 实体已分离，如果您想再次持久化它，则必须使用 ->merge() 方法.

But be aware of that as the $post entity was detached, you must use the ->merge() method if you want to persist it again.

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