Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{"_id":"1","a":1,"b":2,"c":3,"d":4}]
Query
db.collection.update({"_id":"1"},[{"$set":{"a":{"$multiply":["$c","$d"]}}},{"$set":{"b":{"$add":["$a",1]}}}])
Result