在Firestore中按ID提取多个文档 [英] Fetch multiple documents by id in Firestore

问题描述

我目前正在使用新的Firestore作为后端/数据库对Android应用程序进行概念验证.我需要按其ID提取一堆文件(它们都在同一个集合中)

I'm currently doing a proof of concept for an Android app with the new Firestore as backend/db. I need to fetch a bunch of documents by their id (they are all in the same collection)

现在，我遍历id列表，并将它们逐个获取，并将它们存储在列表中，这反过来又会更新应用程序中的RecycleView.这似乎是一项艰巨的工作，并且效果不佳.

Right now, I'm looping thru the id list and fetching them one by one and storing them in a list which in turn updates a RecycleView in the app. This seems to be a lot of work and it does not perform very well.

从Firestore中获取文档列表而不必循环所有id并使其一一获取的正确方法是什么?

What is the correct way to fetch a list of documents from Firestore without having to loop all the ids and getting them one by one?

现在我的代码看起来像这样

Right now my code looks like this

   for (id in ids) {
        FirebaseFirestore.getInstance().collection("test_collection").whereEqualTo(FieldPath.documentId(), id)
                .get()
                .addOnCompleteListener {
                    if (it.isSuccessful) {
                        val res = it.result.map { it.toObject(Test::class.java) }.firstOrNull()

                        if (res != null) {
                            testList.add(res)
                            notifyDataSetChanged()
                        }

                    } else {
                        Log.w(TAG, "Error getting documents.", it.exception)
                    }
                }
    }

推荐答案

Firestore当前不支持按ID查询.

Firestore does not currently support query by IDs.

根据 AngularFirebase ，这是未来的发展路线，但不是官方的:

According to AngularFirebase, this is in the roadmap for development in the future, but its not official:

请记住，Firestore仍处于测试阶段. Firebase工程师在路线图上暗示了一些非常酷的功能(地理位置查询，按ID数组查询)-我一定会向您保证:)

Keep in mind, Firestore is still in beta. Firebase engineers hinted at some really cool features on the roadmap (geo queries, query by array of ids) - I’ll be sure to keep you posted :)

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