Firebase how to sort collection via createdAt field?

Question

I have a collection model that looks like this :

How do I sort the query from latest to oldest via the createdAt field.

So far I tried

db.ref('accounts')
    .startAt()
    .orderByChild('createdAt')
    .once('value')
    .then(function(snap){
        // do shits here...
    })

But am getting the data the oldest on top.

But I want

you can reverse your list after getting but it's better to get reversed from firebase http://stackoverflow.com/a/3963075/3496570 or http://stackoverflow.com/a/10766502/3496570 — Zar E Ahmer, Oct 25 '16 at 06:20
Those are java solutions, well anyways thanks for the idea :) @Nepster — jofftiquez, Oct 25 '16 at 07:50
try limitToLast like http://stackoverflow.com/a/33484784/3496570 or http://stackoverflow.com/a/38024909/3496570 — Zar E Ahmer, Oct 25 '16 at 08:01

score 1 · Accepted Answer · answered Oct 25 '16 at 08:08

1

There is no method to get items sorted in descending order in firebase database. So you need to sort them by ascending and reverse the array in your programming language.
If you want to sort them by time you should be using timestamp instead of datetime as string. In this case you will get wrong ordering because they are actually compared as strings. For example: Imagine this two dates 2016-10-14T02:30:59.653Z, 2016-10-2T02:30:59.653Z. As dates first one is greater but as a strings (lexicographically) second one is greater.

answered Oct 25 '16 at 08:08

!!!!welcome!!!! – Zura Sekhniashvili Oct 25 '16 at 08:15
1

@Zura: It looks like the times are in ISO-8601 format, which requires leading zeros, specifically to ensure that the strings can be lexicographically ordered. – Frank van Puffelen Oct 25 '16 at 14:17
Hello, i know theres been lots of time but, this is working correctly on me ? – ugrdursun May 31 '20 at 12:17

1 Answers1