MongoDB - Update objects in a document's array (nested updating)

Question

Assume we have the following collection, which I have few questions about:

{
    \"_id\" : ObjectId(\"4faaba123412d654fe83hg876\"),
    \"user_id\" : 123456         


        

Answer 1

We can use $set operator to update the nested array inside object filed update the value

db.getCollection('geolocations').update( 
   {
       "_id" : ObjectId("5bd3013ac714ea4959f80115"), 
       "geolocation.country" : "United States of America"
   }, 
   { $set: 
       {
           "geolocation.$.country" : "USA"
       } 
    }, 
   false,
   true
);