我可以将子对象保留在父类的 @PrePersist 处理程序中吗？（客观化 3.1b1）

发布于 2024-12-10 18:36:00 字数 1457 浏览 0 评论 0原文

我是 Objectify 的新手，正在尝试实现一对多关系。我有实体组织和实体人。组织具有 @Transient 属性 List<人>联系人员。 Person 类具有 @Parent 属性 Key<组织> OrganizationKey 我可以通过设置器设置。

我想将 contactPeople 保留在组织的 @PrePersist 处理程序中。为此，我需要在 Person 中设置父密钥。

Wiki 此处说：“您无法更新@PrePersist 回调中的 @Id 或 @Parent 字段；此时，低级实体已经使用完整的 Key 构造完成，因此可以将其作为可选参数传入。”

我不确定这是还是准确的信息？因为我在 PrePersist 处理程序中获取的 com.google.appengine.api.datastore.Entity 对象的键的字面意思是“no-id-yet”。

您将如何实施？

谢谢你！

2011 年 11 月 17 日更新：

在新的 Objectify4 中，我们将能够建立如下所示的半自动关系：

class Beastie {
   @Parent
   @Load
   ParentThing parent;

   @Id Long id;

   @Load({"bigGroup", "smallGroup"})
   SomeThing some;

   @Load("bigGroup")
   List<OtherThing> others;

   @Load
   Ref<OtherThing> refToOtherThing;

   Ref<OtherThing> anotherRef;  // this one is never fetched automatically
}

这里是新版本的不断演变的设计文档。

这是个大新闻。 Twig 作者 John Patterson 今天加入了 Objectify 项目。

原文

I am new to Objectify and trying to implement One-to-Many relationship. I have entities Organization and entity Person. Organization has @Transient property List< Person > contactPeople. Class Person has @Parent property Key< Organization > organizationKey which I can set via setter.

I'd like to persist contactPeople in @PrePersist handler of Organization. In order to do that I need to set parent key in Person.

Wiki here says: "You can't update @Id or @Parent fields in a @PrePersist callback; by this time, the low-level Entity has already been constructed with a complete Key so it can be passed in as an optional parameter."

I'm not sure this is still accurate information ? Because key of com.google.appengine.api.datastore.Entity object that I get in PrePersist handler has key that literally says "no-id-yet".

How would you implement this ?

Thank you!

Update at Nov 17, 2011:

In new Objectify4 we'll be able to do semi-automatic relationships like this:

class Beastie {
   @Parent
   @Load
   ParentThing parent;

   @Id Long id;

   @Load({"bigGroup", "smallGroup"})
   SomeThing some;

   @Load("bigGroup")
   List<OtherThing> others;

   @Load
   Ref<OtherThing> refToOtherThing;

   Ref<OtherThing> anotherRef;  // this one is never fetched automatically
}

Here is evolving design document of new version.

This is big news. Twig author, John Patterson, joined Objectify project today.

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聚集的泪 2024-12-17 18:36:00

嗯，看来你需要在你的数据模型前面创建一个 Dao。因此，您将能够执行以下操作：

Organization organization = ...
List<Person> people = ...
ob.put(organization)
for (Person person: people) {
    person.organizationKey = organization.getKey();
    ob.put(person);
    organization.contactPeopleKeys.add(person.getKey());
}
ob.put(organization)

GAE+Objectify 需要您自己的代码处理很多事情，因此这是很常见的事情

Hm, seems that you need to make an Dao in front of your data models. So, you will able to do something like:

Organization organization = ...
List<Person> people = ...
ob.put(organization)
for (Person person: people) {
    person.organizationKey = organization.getKey();
    ob.put(person);
    organization.contactPeopleKeys.add(person.getKey());
}
ob.put(organization)

GAE+Objectify requires a lot of thing to handle by your own code, so it's a common thing

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