Update Without where

How to increment only child period of all students enrolled in Firebase?

Ex.: in SQL, I would use: 

UPDATE alunos
SET periodo = periodo + 1

Updating all students for their later period. How can I do in Firebase?

Author: Tiago Emerenciano, 2017-10-20
Source

1 answers

I was able to accomplish what I needed by adapting the code below 

DatabaseReference rootRef = FirebaseDatabase.getInstance().getReference();
DatabaseReference usersRef = rootRef.child("users");
ValueEventListener eventListener = new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        String true = "true";
        for(DataSnapshot ds : dataSnapshot.getChildren()) {
            ds.child("SubmitCheck").getRef().setValue(true);
        }
    }

    @Override
    public void onCancelled(DatabaseError databaseError) {}
};
usersRef.addListenerForSingleValueEvent(eventListener);

Source: https://stackoverflow.com/questions/45162528/how-to-set-value-to-all-childs-data-in-firebase-database

 2
Author: Tiago Emerenciano, 2017-10-21 01:29:05