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It does not fetch the required value Firebase Android

It does not fetch the required value and writes null What is wrong with the code please help
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference ref = rootRef.child("analysis_Client").child(searchUserId);
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
userTotal = ds.child("Total").getValue(String.class);
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
//Log.d(TAG, databaseError.getMessage()); //Don't ignore errors!
}
};
A picture of the firebase of the way to list the data I want to call both(Total - Rest - ProductNum)

Firebase Realtime Database delete item in List

I have the data stored in the Realtime Database in this format:
If I wanted to delete one of the entries in the list named 7P3MRvkC2FQkwcyC7CYVWZP9Ps72, I use this code.
The id under this is generated automatically:
FirebaseDatabase.getInstance()
.getReference()
.child("users")
.child(id) -------------------> unique id
.orderByChild("orderId")
.equalTo(orderId,"orderId")
.getRef()
.removeValue();
But this deletes the complete list of users.

Try this code
DatabaseReference ref = FirebaseDatabase.getInstance()
.getReference()
.child("users")
.child(id);
ref.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
dataSnapshot.getRef().removeValue().addOnSuccessListener(new OnSuccessListener<Void>() {
#Override
public void onSuccess(Void aVoid) {
// notify
}
});
}

But this deletes the complete list of users.
That's the expected behavior. If you need to remove only the elements where the orderId property holds the value of a particular "orderId", then you should iterate trough the results like in the following lines of code:
String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference usersRef = rootRef.child("users");
DatabaseReference uidRef = usersRef.child(uid);
Query query = uidRef.orderByChild("orderId").equalTo(orderId);
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
ds.getRef().removeValue();
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Log.d("TAG", databaseError.getMessage()); //Don't ignore potential errors!
}
};
query.addListenerForSingleValueEvent(valueEventListener);

How to retrieve the child data from Firebase?

My database looks as follows, in here I want to retrieve the data inside the mylocation child (see the attached image here). But it is not working.
How to solve that?
My current code looks as this,
private void loadAddress() {
DatabaseReference ref= FirebaseDatabase.getInstance().getReference("Users");
ref.orderByChild("uid").equalTo(firebaseAuth.getUid())
.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for(DataSnapshot ds: dataSnapshot.getChildren()){
String name=""+ds.child("name").getValue();
String lat=""+ds.child("name2").getValue();
addresstv.setText(name);
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}

To get the data under mylocation, you use an explicit call to that child, like in the following lines of code:
String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference uidRef = rootRef.child("Users").child(uid);
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String name = dataSnapshot.child("mylocation").child("name2").getValue(String.class);
double latitude = dataSnapshot.child("mylocation").child("latitude").getValue(Double.class);
double longitude = dataSnapshot.child("mylocation").child("longitude").getValue(Double.class);
Log.d("TAG", name + "/" + latitude + "/" + longitude);
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Log.d("TAG", databaseError.getMessage()); //Don't ignore errors!
}
};
uidRef.addListenerForSingleValueEvent(valueEventListener);
The result in the logcat will be:
5555/79.8571577/6.9448882

How to get the names of the json columns from firebase? I leave an example below my question

I would like to list the names of the dates, such as 24_1_2020, 25_1_2020, etc ...

Assuming that teLm ... IWV2 is the uid of the authenticated user, to display only those keys 24_1_2020, 25_1_2020, please use the following lines of code:
String uid = FirebaseAuth.getInstance().getCurrentUser().getUid();
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference uidRef = rootRef.child("Mensaje").child(uid);
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String key = ds.getKey();
Log.d(TAG, key);
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Log.d(TAG, databaseError.getMessage()); //Don't ignore errors!
}
};
uidRef.addListenerForSingleValueEvent(valueEventListener);
See, I have used the getChildren() method to loop through the DataSnapshot object, which basically contains all children under the uid node. Calling getKey(), you can get each key that is corresponding to each child.
If teLm ... IWV2 is not the uid of the authenticated user, then simply add that String directly in your reference:
DatabaseReference uidRef = rootRef.child("Mensaje").child("teLm ... IWV2");

Retrieve specific value from Firebase database into string variable

I'm trying to retrieve a specific value from a Firebase realtime Database.
The data looks like this:
I want to get the URL value from any of them and then put it into a string variable to use later. This is so that the program does not need to be changed if the download link is changed. The code I have so far is;
DatabaseReference fdb = FirebaseDatabase.getInstance().getReference();
//Query query = fdb.child("URLDOWNLOADS").child("WSSeasons")
fdb.addListenerForSingleValueEvent(new ValueEventListener()
{
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot)
{
for (DataSnapshot url : dataSnapshot.getChildren())
{
LoginInfoFirebasedb DownURL = url.getValue(LoginInfoFirebasedb.class);
String temp = DownURL.dwldURL;
URL1 = temp;
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError)
{
}
});
Some help would be seriously appreciated. I understand this may be a simple problem but I am stumped.

To get each url as a String, please use the following code:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference ref = rootRef.child("URLDOWNLOADS");
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String key = ds.getKey();
String url = ds.child("URL").getValue(String.class);
Log.d(TAG, key + " / " + url);
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
Log.d(TAG, databaseError.getMessage()); //Don't ignore errors!
}
};
ref.addListenerForSingleValueEvent(valueEventListener);