Template
single collection
multiple collections
mgodatagen
update
indexe
explain
Stage
Database
bson
mgodatagen
[{"totalPrice":1},{"totalPrice":2},{"totalPrice":3}]
Query
db.collection.aggregate({"$group":{"_id":null,"totalSales":{$sum:"$totalPrice"},"numOrders":{$sum:1},"avgPrice":{"$avg":"$totalPrice"}}})
Result