Php JMSSerializerBundle，反序列化不'；持续后的t关系

反序列化进程OneToMany MANYTONE进程始终获取关系数据集NULL

结果实体：

@ORM\OneToMany(targetEntity="\Acme\DemoBundle\Entity\AnswerContent", mappedBy="answerResult", cascade={"persist", "remove"}, orphanRemoval=true)
@JMS\Type("ArrayCollection<Acme\DemoBundle\Entity\AnswerContent>")
@JMS\Groups({"survey_answer_fetching"}) 

以下是json：

{"results":
[{"answers":[
{"choices":[{"fieldId":1}],"value":"","questionId":45}, 
{"choices":[{"fieldId":1}],"value":"","questionId":67}],
"someId":9
}],
"personId":18}


$serializer = $this->get('jms_serializer');
$data = $serializer->deserialize($json['json'], 'Acme\\DemoBundle\\Entity\\AnswerResult', 'json');

反序列化过程正在分配这些值

一切正常，所有json变量都设置了正确的实体属性

$em->persist($data);
$em->flush();

值传递到DB，但关系不。。。JMSSerializationBundle的所有文档。所有JMS类型都已定义

---

但是DB/条令没有映射关系

我用merge（）函数解决了同样的问题：

$entity = $em->merge($data);
$em->persist($entity);
$em->flush();

$entity = $em->merge($data);
$em->persist($entity);
$em->flush();