Sorting nested documents in MongoDB?

Question

NoSQL

Hello!
I'm using MongoDB in one of my projects and want to redesign the database, more compactly, using nested documents. Got a question. Let's say there is a collection with a large number of such documents: Actually, the main question with sorting, how can you select the last post by posts.created from all records of all users? How to sort documents by nested fields? I did not find a clear answer in the documentation. It would seem that everything is beautiful and convenient, but sorting breaks off such a structure. Tell me, who had experience with MongoDB, how are these things solved? Thank you.

1. {
2.    "firstname": "Vasya",
3.    "lastname": "Pupkin",
4.    "created": 1300125070,
5.    "ban": 0,
6.    "posts": {
7.     {
8.        "title": "Hello!",
9.        "post": "post post post",
10.        "created": 1300125370,
11.        "hash": "523343633a2fac703e84a3c6afcb3a8a",
12.        "client_ip": "127.0.0.1"
13.     },
14.     {
15.        "title": "Hello again!",
16.        "post": "post post post",
17.        "created": 1300125870,
18.        "hash": "523343633a2fac703e84a3c6afcb3a8a",
19.        "client_ip": "127.0.0.1"
20.     }
21.   }
22. }

Answer 1

sort(array("posts.created" => -1))
should work if I understand you correctly

Answer 2

If posts are added to the end each time they are created, then take the last element of the array. If they are updated, delete and add to the end with each update

Answer 3

I also “smeared” everything by default, but with nested documents it looks prettier and, in theory, it should be more convenient to work with them :)