How to update multiple documents at once in mongodb?

Question

JavaScript

Is it possible to update several documents at once, and with different values?
For example, I send a request:

{
  "5b7abaf46081420c3042867a": { "lastChosen": false },
  "5b7abafe6081420c3042867c": { "lastChosen": true }
}

And I need the documents with these id to be updated according to the objects specified for them. How is it possible to do this? I tried it in a loop, but I don’t understand how it will be correct to return the answer when all queries to the database are over.

Answer 1

1 way, send asynchronously all requests with the key w=0 (loop) except the last one, which is sent with the key w=1 - in 99% it will be processed last and return the completion status
2 use bulkwrite

Answer 2

In fact, before the advent of the clever async library, they simply created a var count = 0 variable and plus it at the end of each callback of accessing the database, after which - in each callback - there was a condition (assume that there are five accesses) "if count == 5, then res.end(...)"
The response was sent - when all asynchronous work was completed.
(for this explanation of the ancient mechanism of "fighting asynchrony" I was once forever banned in Russian Stackoverflow)