mongodb find() order is different from schema order - json

Question

db.blog.save({ title : "My First Post", author: {name : "Jane", id : 1}})
what should below return as the key order does not match?
db.blog.find({"author" : {"id" : 1, "name" : "Jane"}})
EDIT:
based on official mongodb documentation , the keyorder must match (at least for findOne()). It wont return the match-only object using db.blog.findOne({"author" : {"id" : 1, "name" : "Jane"}})

Answer 1

The order of the keys in your query selector is irrelevant. It doesn't need to match the order of the keys you used when adding the document you're searching for.
UPDATE
If you're just looking for an order-independent way to query based on an embedded document, you need to use dot notation:
db.blog.find({"author.id" : 1, "author.name" : "Jane"})

Answer 2

Normally, as #JohnnyHK states the order of the query keys does not matter except for the example you have shown:
db.blog.find({"author" : {"id" : 1, "name" : "Jane"}})
This query will not return results that do not match exactly. Using the query he shows of:
db.blog.find({"author.id" : 1, "author.name" : "Jane"})
Will be key order independent. The reasons for this difference is because in the first query you are searching by an object as such the querier actually searches for exactly that object (in the simplest terms). The same applies for indexes created on the field which contains a set of sub documents, the order does matter.

Answer 3

According to the JSON definition, the key order doesn't matter.
An object is an unordered collection of zero or more name/value pairs
I don't know anything about MongoDB, but I assume it follows the normal rules of JSON, at which point it should return the "My First Post" entry.