CODEWITHSUNDEEP
androidfirebasefirebase-realtime-database
Guilherme Gomes Zucco
Guilherme Gomes Zucco

Reputation: 35

Firebase - compare users in android

well i have a "table" named users and i want to know the number of rows (or child), to compare the next user.

for example: in project Ace, i have this users I am the user MDSxw i would compare with the next (DX47d), but i don't know the name (DX47d).

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In a SQL database i could use a rowcount to know the size of table and with this get the next user and kwon if this is the last user of table

I would know how do it in the firebase, or a way to do something like this.

Upvotes: 0

Views: 40

Answers (1)

Frank van Puffelen
Frank van Puffelen

Reputation: 598765

If you know at what user to start, you can simply do a limitToFirst(2). So:

DatabaseReference usersRef = FirebaseDatabase.getInstance().getReference("users");
Query twoUsers = usersRef.orderByKey().startAt("MDSxw").limitToFirst(2);
twoUsers.addValueEventListener(new ValueEventListener() {
    @Override
    public void onDataChange(DataSnapshot dataSnapshot) {
        for (DataSnapshot userSnapshot: dataSnapshot.getChildren()) {
            System.out.println(userSnapshot.getKey());
        }
    }

Upvotes: 1

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