Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{heros:{superman:51,batman:89,ironman:95}}]
Query
db.collection.aggregate([{$addFields:{allHeros:{$objectToArray:"$heros"}}},{$addFields:{allHeros:"$allHeros.k"}}])
Result