Updating Firebase Database With Nodes Created With Push

I am trying to update a value in my Firebase database. This is the structure of the database: I need to update the value of status to 'accepted' if the r_id and s_id have a specif

Solution 1:

I have finally got this to work after days of trying to figure it out.

I added a Query with orderByChild method to filter out a big chunk of data at the server side itself (thanks to this answer for the idea.) The remaining data which I got as child of data type DataSnapshot had all the necessary information that I needed. Here is the query

Query query = db.orderByChild("r_id").equalTo(f_id);
query.addListenerForSingleValueEvent(newValueEventListener() {
    @OverridepublicvoidonDataChange(DataSnapshot dataSnapshot) {
        for (DataSnapshot child : dataSnapshot.getChildren()) {
            String child_s_id = (String) child.child("s_id").getValue();
            String child_status = (String) child.child("status").getValue();

            if (child_s_id.equals(id)) {
                Log.e("Got value", f_id + " - x -" + id + " " + child_status);

            }
        }
    }

    @OverridepublicvoidonCancelled(DatabaseError databaseError) {

    }
});

But again I could not meet my requirements, because I actually needed to modify one of the value in the child and I could not use any methods like setValue to change the value of child.

Again, it took me a long while (what an idiot) to figure out that I had to convert the child (of data type DataSnapShot) to a reference for setValue to work. And it worked

child.getRef().child("status").setValue("accepted");

Here is the completed code. Hope it helps someone along the way

Query query = db.orderByChild("r_id").equalTo(f_id);
query.addListenerForSingleValueEvent(newValueEventListener() {
    @OverridepublicvoidonDataChange(DataSnapshot dataSnapshot) {
        for (DataSnapshot child : dataSnapshot.getChildren()) {
            String child_s_id = (String) child.child("s_id").getValue();
            String child_status = (String) child.child("status").getValue();

            if (child_s_id.equals(id))
                child.getRef().child("status").setValue("accepted");
        }
    }

    @OverridepublicvoidonCancelled(DatabaseError databaseError) {

    }
});