Firebase & # 8594; date reverse

Question

I am currently building an application using Firebase.

This is one of those message boards that can be seen anywhere on the Internet.

But there was one problem.

This is a matter of sorting by date.

I want to look at a recent date first, but I always see only the data that I created in the first place.

postRef.orderByChild('createData').startAt(reverseDate).limitToFirst(1).on('child_added',(data)=>{
    console.log(data.val().name + data.val().createData);
})

result → hello1496941142093

My firebase tree

My code is the same as above.

How can I check my latest posts first?

How to order a reverse firebase database?

Answer 1

The Firebase database will always return results in ascending order. Unable to change them.

:

• , .
• .

. :

• ,
• firebase
• Firebase?
• : https://www.google.com/search?q=site:stackoverflow.com+firebase+reverse%20sort%20javascript

Answer 2

, .

function reverseObject(object) {
    var newObject = {};
    var keys = [];

    for (var key in object) {
        keys.push(key);
    }

    for (var i = keys.length - 1; i >= 0; i--) {
        var value = object[keys[i]];
        newObject[keys[i]]= value;
    }       

    return newObject;
}

Answer 3

ref.orderBy("name", "desc").limit(3)

Answer 4

Firebase, , , . , -1 . , , , -1

Answer 5

Retrieve data from firebase inse your arraylist, and then

Collections.reverse(YourArrayList<>);