sorting numbers with firebase

Question

I'm storing a score for each player of my game in firebase.

 scores {
     name,
     score
 }

I want to sort the scores by highest to lowest.

This is what I'm trying

 let highestScore = firebase.database().ref('scores').orderByChild('/score');
 highestScore.on('value', getData, (err) => console.log(err));

This is how the database is setup

How can I sort the scores by highest to lowest?

Thank you.

Edit:

This post got be banned from asking questions :( what can I change from it?

can you please add your firebase node structure and some data samples — Pawan Singh, Jul 29 '18 at 12:10
Please also add `getData`. Have a look at [How to create a minimal, complete verifiable example](http://stackoverflow.com/help/mcve), which is the most efficient way to ask for help. — Frank van Puffelen, Jul 29 '18 at 14:03

score 2 · Accepted Answer · answered Jul 29 '18 at 14:06

The Firebase Database always returns results in ascending order. That means you'll need to reverse the results in your client-side code. With your current structure, that means you can implement getData as:

function getData(snapshot) {
  var scores = [];
  snapshot.forEach(function(childSnapshot) {
    scores.unshift(childSnapshot.val());
  });
  console.log(scores);
}

This will show the scores in descending order, since Array.unshift adds the item to the start of the array.

Renaud Tarnec · Answer 2 · 2018-07-29T16:24:55.380

1

Do as follows if you want to get the ranking only once:

    let highestScore = db.ref('scores').orderByChild('score');
    highestScore.once('value', function (snapshot) {
        snapshot.forEach(function (childSnapshot) {
            var childKey = childSnapshot.key;
            console.log(childKey);
            var childData = childSnapshot.val();
            console.log(childData);
        });
    });

edited Jul 29 '18 at 16:24

answered Jul 29 '18 at 12:55

Renaud Tarnec

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score 0 · Answer 3 · answered Jul 29 '18 at 12:12

Did you try one of the suggested functions in the documentation: https://firebase.google.com/docs/database/web/lists-of-data#sort_data

orderByChild()  Order results by the value of a specified child key or nested child path.
orderByKey()    Order results by child keys.
orderByValue()  Order results by child values.

sorting numbers with firebase

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