Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{"_id":"abc","name":"El nombre","cars":[{"_id":"aaa","plate":"algo","gas":1}]}]
Query
db.collection.update({"_id":"abc","cars._id":"aaa"},{$inc:{"cars.$.gas":5}})
Result