Question

我有一个模型类Appointment，其类型为字段， 我需要在Firestore实时数据库中监听并从其subCollection获取所有文档 ，上传逻辑可以完美运行，但是由于这实际上是我第一次进入Firestore，因此在获取数据方面遇到了一些麻烦。

获取文档后 我需要按类型将它们分开 （约会类型A，约会类型B）

这是我到目前为止所获得的，但我似乎无法超越！

PS。以下代码主要基于Firebase文档！

@Override
public void onStart() {
    super.onStart();
    //get all appointments
    mFirestore.collection("reporters").document(mUser.getUid()).collection("appointments")
            .addSnapshotListener(new EventListener<QuerySnapshot>() {
                @Override
                public void onEvent(@Nullable QuerySnapshot queryDocumentSnapshots, @Nullable FirebaseFirestoreException e) {
                    mFirestore.collection("reporters").document().collection("appointments")
                            .whereEqualTo("type", "typeB")
                            .addSnapshotListener(new EventListener<QuerySnapshot>() {
                                @Override
                                public void onEvent(@Nullable QuerySnapshot value,
                                                    @Nullable FirebaseFirestoreException e) {
                                    if (e != null) {
                                        Toast.makeText(getActivity(), "listen failed", Toast.LENGTH_SHORT).show();
                                        return;
                                    }

                                    for (QueryDocumentSnapshot doc : value) {
                                        if (doc.get("name") != null) {
                                            v_appointmentsList.add(doc.toObject(Appointment.class));
                                        }
                                    }
                                }
                            });
                    mFirestore.collection("reporters").document().collection("appointments")
                            .whereEqualTo("type", "typeA")
                            .addSnapshotListener(new EventListener<QuerySnapshot>() {
                                @Override
                                public void onEvent(@Nullable QuerySnapshot value,
                                                    @Nullable FirebaseFirestoreException e) {
                                    if (e != null) {
                                        Toast.makeText(getActivity(), "listen failed", Toast.LENGTH_SHORT).show();
                                        return;
                                    }

                                    for (QueryDocumentSnapshot doc : value) {
                                        if (doc.get("name") != null) {
                                            p_appointmentsList.add(doc.toObject(Appointment.class));
                                        }
                                    }
                                }
                            });
                    //get all docs
                    //....
                    //sort by date [max -> min || min -> max]
                    //...
                    //get index [0] || index [last]
                    //...
                    //if it is vax then affect to variables v_
                    //if it is ped then affect to variables p_
                }
            });
}

Answer 1

对于您的情况，我建议您执行以下操作（我的回答基于下面的评论部分），对于类似的情况，使用实时数据库并不重要，您可以尝试使用此方法：

//colRef is a reference/path to your collection
//filter by type with .whereEqualTo("field", "type")


colRef.whereEqualTo("type", "yourType")
            .get()
            .addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
                @Override
                public void onComplete(@NonNull Task<QuerySnapshot> task) {
                    if (task.isSuccessful()) {
                        for (QueryDocumentSnapshot document : Objects.requireNonNull(task.getResult())) {
                            //add to your arraylist
                        }
                    } else {
                        Toast.makeText(getContext(), "fail to get docs", Toast.LENGTH_SHORT).show();
                    }
                }
            });


//repeat the process for the second type
//if you have more types I suggest using another approach

Android-从子集合中查询所有文档作为对象-Firestore实时数据库

1 个答案: