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How to get all children data Inside a nested key Database in Firebase Realtime Database Android?

I have a database structure as below.
I am able to retrieve the children's data when I give reference to date but I want to retrieve data without referencing to date but the previous nested key.
That is, when I write the following, I am able to get the data:
databaseReference = FirebaseDatabase.getInstance().getReference("LDC Wise").child("Agra").child("25-10-2022");
But when I write the following, I am getting null data:
databaseReference = FirebaseDatabase.getInstance().getReference("LDC Wise").child("Agra")
How do I go about fetching all the data in the next sublevel of the database without referencing to date key explicitly?

How do I go about fetching all the data in the next sublevel of the database without referencing to date key explicitly?
This can be solved by looping through the results twice:
DatabaseReference db = FirebaseDatabase.getInstance().getReference();
DatabaseReference agraRef = db.child("LDC Wise").child("Agra");
agraRef.get().addOnCompleteListener(new OnCompleteListener<DataSnapshot>() {
#Override
public void onComplete(#NonNull Task<DataSnapshot> task) {
if (task.isSuccessful()) {
for (DataSnapshot snapshot : task.getResult().getChildren()) {
for (DataSnapshot innerSnapshot : snapshot.getChildren()) {
//Get the data out of the innerSnapshot object.
}
}
} else {
Log.d("TAG", task.getException().getMessage()); //Never ignore potential errors!
}
}
});

Error in reading the Firebase value: pricecode

Please tell me what is my mistake? I'm trying to count the pricecode and shove it into user -> price. But instead, it gives an error or a link, and not the value "1000"
enter image description here
public void onClickB1 (View view)
{
DatabaseReference bd = FirebaseDatabase.getInstance().getReference("User");
DatabaseReference bd1 = bd.child("pricecode");
String id = mDataBase.getKey();
//String key = dataSnapshot.getKey();
String name = String.valueOf(textB1.getText());
**String price = bd1.child("pricecode").getValue(String.class);**
User newUser = new User(id,name,price);
//mDataBase.push().setValue(newUser);
if (!TextUtils.isEmpty(name)) // проверка пустой строки
{
mDataBase.push().setValue(newUser);
}
else
{
Toast.makeText(this,"Заполните поля",Toast.LENGTH_LONG).show();
}
}

There is no way you can call getValue() on an object of the type DatabaseReference. Why? Because there is no such method inside the class. On the other hand, DataSnapshot class contains a getValue() method. So to be able to read that value, you have to attach a listener as in the following lines of code:
DatabaseReference db = FirebaseDatabase.getInstance().getReference();
DatabaseReference userRef = db.child("User");
userRef.get().addOnCompleteListener(new OnCompleteListener<DataSnapshot>() {
#Override
public void onComplete(#NonNull Task<DataSnapshot> task) {
if (task.isSuccessful()) {
DataSnapshot snapshot = task.getResult();
String priceCode = snapshot.child("pricecode").getValue(String.class);
Log.d("TAG", "priceCode: " + priceCode);
} else {
Log.d("TAG", task.getException().getMessage()); //Never ignore potential errors!
}
}
});
As I already mentioned in an earlier question of yours, store the prices as numbers and not strings.

How we can retrieve uid user name and the uid user child value in RecyclerView in Android Java?

How can we access all UID users name and the UID users child value in Firebase database?
I have uploaded the pic of my database
I also use RecyclerView you tell me about Firebase query I want to retrieve data with FirestoreRecyclerOptions query :
I want to access
name of users and the amount value as shown in fig
like this
name:600

To get all user names, of all User objects that exist under "Users" node, please use the following lines of code:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference usersRef = rootRef.child("Users");
productsRef.get().addOnCompleteListener(new OnCompleteListener<DataSnapshot>() {
#Override
public void onComplete(#NonNull Task<DataSnapshot> task) {
if (task.isSuccessful()) {
for (DataSnapshot ds : task.getResult().getChildren()) {
String name = ds.child("name").getValue(String.class);
Log.d(TAG, name);
}
} else {
Log.d(TAG, task.getException().getMessage()); //Don't ignore potential errors!
}
}
});
Because there are several objects within the "Users" node, first you need to get a reference to that node, attach a listener and then loop through the results. The result in the logcat will be:
jm
...
If you want to use the Firebase-UI library, then simply pass the "usersRef" to the FirestoreRecyclerOptions's setQuery() method, as explained in my answer from the following post:
How to display data from Firestore in a RecyclerView with Android?

Reading data from Firebase Realtime Database for a specific user

What is the proper way to read data from Firebase Realtime Database? I have created a database "Mybill"s with child bills. In child Bills, I am saving UserId from FirebaseAuth so it should be easy to find bills for a specific user and in userID child, I have a child that I have created using the .push() method and in that, I have data about the bill.
It looks like this:
How should I change my Java code so I can get all the bills saved for a specific user (the user that is currently logged in)
this is my code for now :
final FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference ref = database.getReference("bills");
Query checkUser = ref.orderByChild("UserId").equalTo(Autentication.GetUser());
// Attach a listener to read the data at our posts reference
checkUser.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String email = dataSnapshot.child("email").getValue(String.class);
String market = dataSnapshot.child("market").getValue(String.class);
String price = dataSnapshot.child("price").getValue(String.class);
String date = dataSnapshot.child("date").getValue(String.class);
}
#Override
public void onCancelled(DatabaseError databaseError) {
System.out.println("The read failed: " + databaseError.getCode());
}
});

How should I change my Java code so I can get all the bills saved for a specific user (the user that is currently logged in)
To do that, please use the following lines of code:
String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference uidRef = rootRef.child("bills").child(uid);
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String email = ds .child("email").getValue(String.class);
String market = ds .child("market").getValue(String.class);
String price = ds .child("price").getValue(String.class);
Log.d("TAG", email + "/" + market + "/" + price);
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Log.d("TAG", databaseError.getMessage()); //Don't ignore potential errors!
}
};
uidRef.addListenerForSingleValueEvent(valueEventListener);
The "date" cannot be read as a String, as it's an object. So the most appropriate way would be to read it as a Map<String, Object>. In this way, you are getting only the bills that correspond to a specific user (logged-in user).

Android Firebase Fetch Data Of Every User

For example, there are 2 main nodes in my database (there can be more). The parent node is the user's authentication id and inside it
there is some detail as you can see.
I am trying to do that if any user login all other user's data populated on his activity
but I really don't know how to start because every user has its own authentication id and there are sub-nodes also like map location and image
How can I fetch every user's detail to the activity?

What you can do is that get the data from the fbuserinfo node using an event listener like this and iterate through the data. Here User.class is the class for the User model that you have created
DatabaseReference userDataReference = FirebaseDatabase.getInstance().getReference()
.child("fbuserinfo");
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot ds : dataSnapshot.getChildren()) {
User user = ds.getValue(User.class);
Log.d("User", user);
}
}
}
#Override
public void onCancelled (DatabaseError databaseError){
Log.d(TAG, "Error fetching user data - " + databaseError.getMessage());
}
}
userDataReference.addListenerForSingleValueEvent(eventListener);
And then if you want to display the data, you can do it in the for loop and have an if condition to check if the user is not equal to the current one

Using the following example you'll be able to log the name of all users from your database.
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference fbRef = rootRef.child("Users").child("fbusersinfo");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String name = ds.child("name").getValue(String.class);
Log.d("TAG", name);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
fbRef.addListenerForSingleValueEvent(eventListener);
The output will be:
Ahmend Abbas
mahanoor 4
If you need also the other properties, you can get them in the same manner.