Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{A:1,B:2}]
Query
db.collection.aggregate([{$project:{_id:0,obtoar:{$objectToArray:"$$ROOT"}}},{$project:{keys:"$obtoar.k",/** values: "$obtoar.v"*/}}])
Result