如何从 Firestore 数据库中检索特定数据？

Question

I am trying to find the mobile number of a user from the Firestore database which has all the user details after checking a condition which says if the flat and the block number of the user matches with the entry in flat and block than retrieve his mobile number.

The image shows the screenshot of database.

Answer 1

If i understand you correctly, try something like this:

 FirebaseFirestore  fireStore = FirebaseFirestore.getInstance();
        final String[] requiredMobile = {""}; //this is up to how you want to use the mobile number acquired
        fireStore.collection("users").get().addOnSuccessListener(new OnSuccessListener<QuerySnapshot>() {
            @Override
            public void onSuccess(QuerySnapshot documentSnapshot) {
                for (DocumentSnapshot document: documentSnapshot.getDocuments()
                     ) {
                    if(document.getString("flat")== ("desired Flat") && document.getString("block") =="desired blockNumber"){
                        requiredMobile[0] = document.getString("mobile"); //do something with phone number
                    }

                }
            }
        });