Datasnapshot Could Not Get Parent Push Key Value

I want dataSnapshot to check if 'month' exists in its parent's 'summary'. But dataSnapshot is returning that it does not have 'month' in 'summary' ds = FirebaseDatabase.getInstanc

Solution 1:

The following line of code:

Stringkey = ds.getKey();

Returns the key of the node on which the reference is pointing to, in this case summary. Between the summary node and the month property, there is another level in your structure, which actually is that pushed key (-MJKC ... xGZX). In order to check if that property exists, you need to use that key in the reference too. Assuming that the summary node is a direct node of your Firebase database root, please use the following lines of code:

DatabaseReferencerootRef= FirebaseDatabase.getInstance().getReference();
DatabaseReferencekeyRef= rootRef.child("summary").child("-MJKC_JkVFpCdCGqxGZX");
ValueEventListenervalueEventListener=newValueEventListener() {
    @OverridepublicvoidonDataChange(DataSnapshot dataSnapshot) {
        if (dataSnapshot.hasChild("month")) {
            Toast.makeText(newTransaction.this, "got value", Toast.LENGTH_LONG).show();
        } else {
            Toast.makeText(newTransaction.this, "No value", Toast.LENGTH_LONG).show();
        }
    }

    @OverridepublicvoidonCancelled(@NonNull DatabaseError databaseError) {
        Log.d("TAG", databaseError.getMessage()); //Don't ignore potential errors!
    }
};
keyRef.addListenerForSingleValueEvent(valueEventListener);

However, you haven't store that key into a variable, then you should use a query, as below:

DatabaseReferencerootRef= FirebaseDatabase.getInstance().getReference();
DatabaseReferencesummaryRef= rootRef.child("summary");
QueryqueryByMonth= summaryRef.orderByChild("month")
ValueEventListenervalueEventListener=newValueEventListener() {
    @OverridepublicvoidonDataChange(DataSnapshot dataSnapshot) {
        if (dataSnapshot.exists()) {
            Toast.makeText(newTransaction.this, "got value", Toast.LENGTH_LONG).show();
        } else {
            Toast.makeText(newTransaction.this, "No value", Toast.LENGTH_LONG).show();
        }
    }

    @OverridepublicvoidonCancelled(@NonNull DatabaseError databaseError) {
        Log.d("TAG", databaseError.getMessage()); //Don't ignore potential errors!
    }
};
queryByMonth.addListenerForSingleValueEvent(valueEventListener);