Develop Reference

fetching related data using the same uid

i trying to read related data from dataorder which related using userID from datauser.
private void cobacoba(){
FirebaseUser user= FirebaseAuth.getInstance().getCurrentUser();
String userid = user.getUid();
DatabaseReference databaseUser = FirebaseDatabase.getInstance().getReference("datauser");
databaseUser.child(userid).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
String nama = dataSnapshot.getValue(dataUser.class).getUserId();
hey.setText("haloo "+nama);
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}
i use code above to read data from datauser but how do i read the related data on dataorder ?
i try the same way to read the idOrder from dataorder but the value always null. can some one help please ?
FirebaseUser user= FirebaseAuth.getInstance().getCurrentUser();
final String userid = user.getUid();
DatabaseReference databaseOrder = FirebaseDatabase.getInstance().getReference("dataorder");
databaseOrder.child(userid).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
final String idorder = dataSnapshot.getValue(dataOrder.class).getIdOrder();
if (!TextUtils.isEmpty(idorder)){
status.setText(idorder);
FirebaseUser user= FirebaseAuth.getInstance().getCurrentUser();
final String userid = user.getUid();
final DatabaseReference databaseOrder = FirebaseDatabase.getInstance().getReference("dataorder");
databaseOrder.child(userid).child(idorder).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
String haritanggal = dataSnapshot.getValue(dataOrder.class).getHaritanggalOrder();
String jamlapangan = dataSnapshot.getValue(dataOrder.class).getLapanganjamOrder();
idordeer.setText("Order ID = "+idorder);
jamtanggal.setText("Tanggal dan Waktu = "+jamlapangan+" Tanggal "+haritanggal);
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}else {
status.setText("no current order");
}
status.setText("id anda= "+idorder+" ....."); //<<<id value always null, why ?????
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
using code above, i discover idOrder always null thats why i cannot access the data inside it, because i don't have the key. any sugestion please ?

Please check your query :
databaseUser.child(userid).child(idorder)
instead use :
databaseOrder.child(userid).child(idorder)

Query Specific Child Form Firebase

I have the structure in the image below and I want to get the whole data from ALL NODES querying by "amount". How can I do that query? How can I get amount value from all the nodes because all roots are different.
I treid:
zonesRef= FirebaseDatabase.getInstance().getReference("Database");
zone1Ref = zonesRef.child("Payments");
Query queryRef = zone1Ref.orderByChild("amount");
queryRef.addChildEventListener(new ChildEventListener() {
#Override
public void onChildAdded(#NonNull DataSnapshot dataSnapshot, #Nullable String s) {
Toast.makeText(getApplicationContext(),s,Toast.LENGTH_SHORT).show();
}
I have differnt users with different UserID. Here is code which i am usign to push data to firebase.
currentFirebaseUser = FirebaseAuth.getInstance().getCurrentUser() ;
UserID= currentFirebaseUser.getUid().toString();
zonesRef= FirebaseDatabase.getInstance().getReference("Database");
zone1Ref = zonesRef.child(Type);
zone1NameRef = zone1Ref.child(UserID);
Submit.setOnClickListener(new View.OnClickListener() {
#Override
public void onClick(View v) {
String Amount2= Amount.getText().toString();
String Description2= Description.getText().toString().trim();
String uniqueKey = zone1NameRef.push().getKey();
UniqueKey= zone1NameRef.child(uniqueKey);
UniqueKey.child("amount").setValue(Amount2);
UniqueKey.child("date").setValue(currentDateTimeString);
UniqueKey.child("description").setValue(Description2);
UniqueKey.child("school").setValue(School);
}
});

Upon checking your data structure you have two keys before accessing the amount.
DatabaseReference getKeys;
DatabaseReference Amounts;
getKeys = FirebaseDatabase.getInstance().getReference("Database");
Amounts = FirebaseDatabase.getInstance().getReference("Database");
getKeys.child("Payments").addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for (DataSnapshot snapshot:dataSnapshot.getChildren()){
String key = snapshot.getKey();
Amounts.child("Payments").child(key).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for(DataSnapshot snapshot1:dataSnapshot.getChildren()) {
String amount = snapshot1.child("amount").getValue(String.class);
Toast.makeText(getApplicationContext(),amount,Toast.LENGTH_SHORT).show();
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});
}
}
#Override
public void onCancelled(#NonNull DatabaseError databaseError) {
}
});

Retrieve Current User's Data (user_id) Firebase?

firebaseAuth = FirebaseAuth.getInstance();
mDatabase = FirebaseDatabase.getInstance();
mDb = mDatabase.getReference();
FirebaseUser user = firebaseAuth.getCurrentUser();
userKey = user.getUid();
mDb.child(userKey).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
Log.d(TAG, "Name: " + dataSnapshot.child("user_id").getValue());
userID = String.valueOf(dataSnapshot.child("user_id").getValue());
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
I do not know what is wrong with my code, I want to retrieve value of user id.

To solve this, please use the following code:
firebaseAuth = FirebaseAuth.getInstance();
mDatabase = FirebaseDatabase.getInstance();
mDb = mDatabase.getReference();
FirebaseUser user = firebaseAuth.getCurrentUser();
userKey = user.getUid();
mDb.child("Tunanetra").child(userKey).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String userID = dataSnapshot.child("user_id").getValue(String.class);
Log.d(TAG, "Name: " + userID);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
});
With this code, you'll be able to print out in the logcat, the id of the users that is authenticated and exists under Tunanetra node. If the user exists under the Orangtua node, then just change Tunanetra with Orangtua.

I think instead of
mDb = mDatabase.getReference();
you should be using
mDb = mDatabase.getReference("Tunanetra");
because that's where the user you're looking for is nested at.

It's simple.
If you want to retrieve user data. Then you have to first select the child node in which you want to look for the user.
You have to Nodes Tunanetra and Orangtua
Else you can try this order by approach.
FirebaseAuth firebaseAuth = FirebaseAuth.getInstance();
FirebaseDatabase mDatabase = FirebaseDatabase.getInstance();
DatabaseReference mDb = mDatabase.getReference();
FirebaseUser user = firebaseAuth.getCurrentUser();
String userKey = user.getUid();
//First Approach
mDb.child("Tunanetra").child(userKey).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String userID = String.valueOf(dataSnapshot.child("user_id").getValue());
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
//Second Approach
mDb.child("Tunanetra").orderByChild("email").equalTo(user.getEmail()).limitToFirst(1).addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if(dataSnapshot.getChildrenCount()>0){
for(DataSnapshot data : dataSnapshot.getChildren()){
String userID = String.valueOf(data.child("user_id").getValue());
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});

Firebase to Android

I would like to put this fields "age, email, firstname" [you can see clicking in the Tree of Firebase above] in three Strings "userAge, userEmail, userName" and put then in a text view, when I use this code to get the name
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference ref = database.getReference();
String userId;
String userName;
//.
//.
//.
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
if (user == null) {
finish();
} else {
userId = user.getUid();
ref.child("users").child(userId).child("firstname").addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
userName = dataSnapshot.getValue(String.class);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
textview.setText(userName);
I can get the name and put in the String userName, and show it in the text view
but when I try tpo get the 3 fields with this code:
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference ref = database.getReference();
String userId, UserName, userEmail, userAge
//.
//.
//.
FirebaseUser user = FirebaseAuth.getInstance().getCurrentUser();
if (user == null) {
finish();
} else {
userId = user.getUid();
ref.child("users").child(userId).child("firstname").addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
userName = dataSnapshot.getValue(String.class);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
ref.child("users").child(userId).child("email").addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
userEmail = dataSnapshot.getValue(String.class);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
ref.child("users").child(userId).child("age").addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
userAge = dataSnapshot.getValue(String.class);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
textview.setText(userName + ", " + userAge + "Years - " + useremail);
The App doesn't get the fields and closes, have another way to do this?

Use Integer.class instead of String.class for I saw your data on Firebase is NOT in a quote so it should be retrieve in Integer format.
ref.child("users").child(userId).child("age").addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
userAge = dataSnapshot.getValue(Integer.class);
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
}

Actually your issue might be because age is an integer and you are trying to retrieve it as a string. Can you try commenting out age part of the code and see if it works?

Firebase Query get values

I have a list of Child-Data and wants to have a certain value.
My Firebase structure:
Now, I only have the Child "Text" and the currendUser "0zwtyRwgnogC8Qk91AtHj7amZb63"
So how can I get the values of "text and "user_id"?
My source code:
mDatabaseText = FirebaseDatabase.getInstance().getReference().child("Text");
query = mDatabaseText.startAt(mCurrentUser.getUid());
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
if (dataSnapshot.exists()) {
for (DataSnapshot textSnapshot : dataSnapshot.getChildren()) {
/* String text = textSnapshot.getKey();
Toast.makeText(getActivity(), text, Toast.LENGTH_SHORT).show(); */
TextModel textModel = chatSnapshot.getValue(TextModel.class);
String t = textModel.getText();
Log.i("!!!!!!!text", t);
Toast.makeText(getActivity(), t, Toast.LENGTH_SHORT).show();
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
But this code doesn't work, why?
I used the query startAt.

Please use this code:
FirebaseDatabase rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference currentUserIdRef = rootRef.child("Text").child(currentUserId);
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String userId = (String) ds.getKey();
DatabaseReference userIdRef = rootRef.child("Text").child(currentUserId).child(userId);
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String user_id = (String) dataSnapshot.child("user_id").getValue();
}
#Override
public void onCancelled(DatabaseError databaseError) {
throw databaseError.toException(); // don't ignore errors
}
};
userIdRef.addListenerForSingleValueEvent(eventListener);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
throw databaseError.toException(); // don't ignore errors
}
};
currentUserIdRef.addListenerForSingleValueEvent(eventListener);
In which currentUserId is the variable that you say you already have it.
Hope it helps.