java如何使用Firestore向文档中的哈希映射数组添加数据？

Question

我希望在不覆盖的情况下将数据添加到现有阵列。在每个文档中，我有一个数组HashMap。我正在尝试向现有数据添加数据。请检查下面的代码，并提供一些信息

   public void createNewCase(){
     Map<String, String> caseInfo = new HashMap<String, String>();


    caseInfo.put("chief_complaint", chiefComplaintET.getText().toString());
        caseInfo.put("facility", facilityET.getText().toString());
        caseInfo.put("location", locationET.getText().toString());
        caseInfo.put("assigned_provider", assignProviderET.getText().toString());
        caseInfo.put("referring_provider", referringProviderET.getText().toString());
        caseInfo.put("admit_date", adminDateET.getText().toString());
        caseDictionary.add(caseInfo);
        final String patientID = sharedPrefHelper.getStr("patient_id");



        db.collection("patients").whereEqualTo("patient_id", patientID).get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
            private static final String TAG = "New Case Creation" ;

            @Override
            public void onComplete(@NonNull Task<QuerySnapshot> task) {
                if (task.isSuccessful()) {
                    List<HashMap<String,String>> list = new ArrayList<>();
                    for (QueryDocumentSnapshot document : task.getResult()) {
                        patient patient = new patient();
                        list = (List) document.get("patient_case");
                        for (HashMap<String, String> item:list) {
                            caseDictionary.add(item);
                        }
                    }
                    System.out.println(caseDictionary);
                    HashMap<String, Object> uploadData = new HashMap<>();
                    uploadData.put("patient_case", caseDictionary);
                    DocumentReference caseRef = db.collection("patients").document(patientID); // am stuck here

                }else{
                    Log.w(TAG, "Error getting documents.", task.getException());
                    Toast.makeText(NewCase.this, "Something bad happened", Toast.LENGTH_SHORT).show();
                    Helper.m_Dialog.hide();
                }

            }
        });

}

编辑1 下面的代码删除旧数据并添加新数据。我需要追加

   final String patientID = sharedPrefHelper.getStr("patient_id");
        final CollectionReference collectionReference = db.collection("patients");
    collectionReference.whereEqualTo("patient_id", patientID).get().addOnCompleteListener(new OnCompleteListener<QuerySnapshot>() {
        @Override
        public void onComplete(@NonNull Task<QuerySnapshot> task) {
            Toast.makeText(NewCase.this, task.getResult().toString(), Toast.LENGTH_SHORT).show();
            if (task.isSuccessful()) {
                for (QueryDocumentSnapshot document : task.getResult()) {

                    Map<Object, Object> map = new HashMap<>();
                    map.put("patient_case", caseInfo);

                    collectionReference.document(document.getId()).set(map, SetOptions.merge());
                }
            }else{
                Toast.makeText(NewCase.this, task.getResult().toString(), Toast.LENGTH_SHORT).show();
            }
        }
    });

Answer 1

• 这是我的一个例子

• 我是这样做的

   List<Map> history = List();  
  
   History historyObj = History(typee, name, timeStamp, pointsBefore, points, itemPoints);  
  
   history.add(historyObj.toMap());  
  
   //Firesore collection object  
  
   CollectionReference child = _firestore.collection('children');  
  
   //Firesore document object  
  
   DocumentReference docRef = child.doc(selectedChild.childId);  
  
   // "history" is your "patient_case"  
  
   docRef.update({"history": FieldValue.arrayUnion(history)}).then(
       (value) => print("Update done"));  
  

• 历史是我的一门课

• 历史类包括方法toMap（），该方法将所有历史类变量及其值转换为“Key”：“value”形式，如下所示

  Map<String, dynamic> toMap() => {  
       "type": type,
       "name": name,
       "timestamp": timestamp,
       "points_before": points_before,
       "points_after": points_after,
       "points_affected": points_affected,
     };
  

Answer 2

正如我在您的屏幕截图中看到的，在patients集合中，您的文档包含一个包含贴图（对象）的数组。为了能够更新数组中存在的映射，您应该创建一个Map对象，该对象对应于您的确切文档结构，并使用DocumentReference的set(Object data, SetOptions options)方法进行更新。因此，将map作为第一个参数传递，并作为第二个参数SetOptions.merge()。你可以在我的回答中从下面的帖子中找到一个更简单的例子：

• Firestore firebase Android search and update query