通过Id查询Morphia [英] Querying Morphia by Id

问题描述

我正在使用Morphia，MongoDB的Pojo映射器，我觉得很难在我看来应该很简单的任务：通过id获取一个对象。我能够找到集合中的所有对象，但我无法弄清楚使用从列表中获取的ID查询的简单任务。我实际上是在谈论ObjectId。如果我尝试用JSON渲染它，我看到

I am using Morphia, the Pojo mapper for MongoDB, and I find difficult a task that in my view should be very simple: getting an object by id. I am able to find all the objects in a collection but I cannot figure out the simple task of querying using an id I got from the list. I am actually talking about the ObjectId. If I try to render it in JSON I see

推荐答案

这个问题似乎不完整。

您的问题似乎也在于 Morphia快速入门页面。似乎很简单如下。

It also seems like the answer to you question is on the Morphia QuickStart page. Seems to be as simple as follows.

Datastore ds = morphia.createDatastore("testDB");
String hotelId = ...; // the ID of the hotel we want to load
// and then map it to our Hotel object
Hotel hotel = ds.get(Hotel.class, hotelId);

所以你肯定需要更多细节。

So you'll definitely need more details.

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