Delete multiple datas sharing a same child from Firebase - Java - orderByKey

I have the following Firebase Database :

I need to delete all the entries/database objects sharing the same "date_cours" type.

I tried the following method to delete all the entries sharing the same date_cours "10/09/2018", for example :

private void Delete_CR_Lessons(Date date)
final String date_a_supprimer_string = DateFormat.getDateInstance(DateFormat.SHORT).format(date);

DatabaseReference drTest = FirebaseDatabase.getInstance().getReference("cours");

drTest.child("date_cours").orderByKey().equalTo("10/09/2018")
.addListenerForSingleValueEvent(new ValueEventListener()
@Override
public void onDataChange(DataSnapshot dataSnapshot)
Log.i("Tag", "test1");

for (DataSnapshot postsnapshot :dataSnapshot.getChildren())
Log.i("Tag", "test2");
String key = postsnapshot.getKey();
dataSnapshot.getRef().removeValue();



@Override
public void onCancelled(DatabaseError databaseError)
Log.w("TAG: ", databaseError.getMessage());

);
//fin de la methode Delete_CR_Lessons


I have no error during the execution of the method.
In the Logs, I can see my Log "test1" but not the log "test2".

Does anyone know what I am missing ?

orderByChild

1 Answer
1

You are providing wrong path and than you are trying to delete wrong datasnapshot value for example try to use: postsnapshot.getRef().removeValue(); instead of dataSnapshot.getRef().removeValue(); because dataSnapshot doesn't point to the value which you want to delete. That is why you used for loop to get all value nodes from your database. Check code below:

datasnapshot

postsnapshot.getRef().removeValue();

dataSnapshot.getRef().removeValue();

dataSnapshot

for

DatabaseReference drTest = FirebaseDatabase.getInstance().getReference("cours");

drTest.orderByChild("date_cours").equalTo("01/10/2018")
.addListenerForSingleValueEvent(new ValueEventListener()
@Override
public void onDataChange(DataSnapshot dataSnapshot)

Log.i("Tag", "test1");

for (DataSnapshot postsnapshot :dataSnapshot.getChildren())
Log.i("Tag", "test2");
String key = postsnapshot.getKey();
postsnapshot.getRef().removeValue();





@Override
public void onCancelled(DatabaseError databaseError)
Log.w("TAG: ", databaseError.getMessage());


);


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