Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{"id":1,"devices":[{"id":1,},{"id":2}]},{"id":2,"devices":[{"id":1,},{"id":2}]}]
Query
db.collection.find({"id":1,"devices":{"$elemMatch":{"id":1}}},{"devices.$":1})
Result