Select query in database firebase Android

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Select query in database firebase Android

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#1 by (1 votes)

1

I have the following database in firebase

Now I want to bring the titles of the cities depending on their zone number

I tried to bring the data and put it in a TextView but so far it shows nothing

DatabaseReference myRef = FirebaseDatabase.getInstance().getReference();
        Query query = myRef.child("cities");
        query.addListenerForSingleValueEvent(new ValueEventListener() {
            @Override
            public void onDataChange(DataSnapshot dataSnapshot) {
                if (dataSnapshot.exists()) {
                    for (DataSnapshot citi : dataSnapshot.getChildren()) {
                        txt.setText(citi.getValue().toString());
                    }
                }
            }

            @Override
            public void onCancelled(DatabaseError databaseError) {

            }
        });

android firebase

asked by leonel Medel Ilhuicatzi 19.03.2018 в 15:55

source

1 answer

Div and Responsive Content how do I update the records in a database?

score 1 · Answer 1

We retrieve the "cities" that for example have "zone" in 2. Here I leave a good page for you to see how to ask questions link

Long zona_deseada=new Long(2);

DatabaseReference myRef = FirebaseDatabase.getInstance().getReference();
    Query query = myRef.child("cities").orderByChild("zone").equalTo(zona_deseada);
 query.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            if (dataSnapshot.exists()) {
                for (DataSnapshot citi : dataSnapshot.getChildren()) {
                    txt.setText(citi.getValue().toString());
                }
            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });