Develop Reference

I want all phone numbers and their respective Bidding Amount from Firebase

How to fetch this Data
I only want number and their respective bidding amount.
This id my code:
databaseReference.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
Map<String, Object> map = (HashMap<String, Object>) dataSnapshot.child(statusScreenLoaders.get(position).getItemName()).getValue();
for ( String key : map.keySet() ) {
Log.d(TAG, "onDataChange: "+key);
}
for (Object value:map.values()){
Log.d(TAG, "onDataChange: " +value);
}

You can do the following to get the number:
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("KitKat");
ref.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()){
String key = ds.getKey();
}
}
String key = ds.getKey(); will return then number that you want. You can then create another reference inside the for loop to get the data of the binding amount:
DatabaseReference ref = FirebaseDatabase.getInstance().getReference("KitKat");
ref.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()){
String key = ds.getKey();
DatabaseReference reference = FirebaseDatabase.getInstance().getReference("KitKat").child(key);
reference.child("BiddingAmount").addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(#NonNull DataSnapshot dataSnapshot) {
String num = dataSnapshot.child("0").getValue(String.class);
}
}
}

How to search through data in firebase android from given structure

I want to search through data in firebase like here:
I have already tried, but it not works
//Query query = FirebaseDatabase.getInstance().getReference(uid).orderByChild("title").startAt(editable.toString()).endAt(editable.toString()+"\uf888");
DatabaseReference databaseReference = FirebaseDatabase.getInstance().getReference("categoreis");
Query query = FirebaseDatabase.getInstance().getReference("categoreis").limitToFirst(4).orderByChild("image");
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
list.clear();
for (DataSnapshot data:dataSnapshot.getChildren())
{
for (DataSnapshot ds:data.child("SubAccessories").getChildren())
{
for (DataSnapshot ds1:ds.getChildren())
{
//Log.d("checkData1",ds1.toString());
//Log.d("checkData1",ds1.child("image").getValue(String.class));
}
}
}

If you want to get the image as I see in your question, please use the following lines of code but assuming that the categories node is a direct child of your Firebase database root:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference ref = rootRef.child("categories/Accessories/SubAccessories/Accessories/Grab Bar");
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
String image = dataSnapshot.child("image").getValue(String.class);
Log.d("TAG", image);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
ref.addListenerForSingleValueEvent(valueEventListener);
According to your comment, you should loop through the second Accessories node using getChildren() method like this:
DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference ref = rootRef.child("categories/Accessories/SubAccessories/Accessories");
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot ds : dataSnapshot.getChildren()) {
String image = dataSnapshot.child("image").getValue(String.class);
Log.d("TAG", image);
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
ref.addListenerForSingleValueEvent(valueEventListener);

Firebase query in tree with depth and multiple children

I have a problem regarding querying the firebase database using a value and getting the specific node. My schema is shown here:
In my schema 'workLocations' belongs to an 'excavationWorks', and 'excavationWorks' belongs to an 'excavationLists'.
That means that the path to a specific workLocation is excavationLists/excavationWorks/workLocations/(specific workLocation)
The problem that I have is that I want to query the workLocations node by the location value (let's say London) and get the parent node (the red circled key which is the key of the specific workLocation).
I have search and read many posts but I haven't managed to make it work.
My code looks like this:
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
Query query = reference.child("workLocations").orderByChild("location").equalTo("London");
query.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot workLoc : dataSnapshot.getChildren()) {
// do something with the individual "issues"
Log.d(TAG, workLoc.getKey());
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});
Thank you

To achieve this, you need to query your database twice like this:
DatabaseReference reference = FirebaseDatabase.getInstance().getReference();
DatabaseReference workLocationsRef = reference
.child("excavationLists")
.child("excavationWorks")
.child("workLocations");
ValueEventListener valueEventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot dSnapshot : dataSnapshot.getChildren()) {
for(DataSnapshot ds : dSnapshot.getChildren()) {
String key = ds.getKey();
Query query = workLocationsRef.child(key).orderByChild("location").equalTo("London");
ValueEventListener eventListener = new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot snapshot) {
String description = snapshot.child("description").getValue(String.class);
Log.d("description", description);
String partentKey = snapshot.getRef().getParent().getKey();
Log.d("partentKey", partentKey);
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
query.addListenerForSingleValueEvent(eventListener);
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {}
};
workLocationsRef.addListenerForSingleValueEvent(valueEventListener);

Firebase android ordering

I'm unable to order result with orderByChild on a date field (timestamp)
Here the structure of data :
And the code :
DatabaseReference mMessagesRef = FirebaseDatabase.getInstance().getReference().child("messages")
.child(mConversationId).getRef()
.orderByChild("date").getRef();
mMessagesRef.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot data: dataSnapshot.getChildren()){
The query returned the value, but not ordered by date, it's return by key..

Try this:
DatabaseReference mMessagesRef=FirebaseDatabase.getInstance().getReference();
Query queryRef = mMessagesRef.child("messages").orderByChild("date");
queryRef.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for(DataSnapshot data: dataSnapshot.getChildren()){

Retrieving specific node from firebase database in android

I am trying to use Firebase in my android application. I need to get an object, i am searching with its email (attribute in the object).
this is my code of search:
FirebaseDatabase database = FirebaseDatabase.getInstance();
DatabaseReference myRef = database.getReference("Remorqueur");
Query queryRef=myRef.orderByChild("email").equalTo(ed_mail.getText().toString());
If the object exists in my database I need to get the whole object back! how can I do it?

should be able to do something like following
queryRef.addListenerForSingleValueEvent(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot childSnapshot: dataSnapshot.getChildren()) {
MyPojo app = childSnapshot.getValue(MyPojo.class);
}

Try this Please
DatabaseReference dbRef = firebaseDatabase.getReference("Remorqueur");
Query query = profileDbRef
.orderByChild("email")
.equalTo(ed_mail.getText().toString());
query.addValueEventListener(new ValueEventListener() {
#Override
public void onDataChange(DataSnapshot dataSnapshot) {
for (DataSnapshot dataSnapshot1 : dataSnapshot.getChildren()) {
Log.d(TAG, dataSnapshot1.getKey() + " " + dataSnapshot1.getValue(Profile.class)
.toString());
}
}
}
#Override
public void onCancelled(DatabaseError databaseError) {
}
});