A sequence of data aggregation processes. These can either be given as separate parameters, or as a single array parameter.
An array of documents returned by the pipeline
Exception if a DB communication error occured
Example taken from the MongoDB documentation
import vibe.db.mongo.mongo; void test() { auto db = connectMongoDB("127.0.0.1").getDatabase("test"); auto results = db["coll"].aggregate( ["$match": ["status": "A"]], ["$group": ["_id": Bson("$cust_id"), "total": Bson(["$sum": Bson("$amount")])]], ["$sort": ["total": -1]]); }
The same example, but using an array of arguments
import vibe.db.mongo.mongo; void test() { auto db = connectMongoDB("127.0.0.1").getDatabase("test"); Bson[] args; args ~= serializeToBson(["$match": ["status": "A"]]); args ~= serializeToBson(["$group": ["_id": Bson("$cust_id"), "total": Bson(["$sum": Bson("$amount")])]]); args ~= serializeToBson(["$sort": ["total": -1]]); auto results = db["coll"].aggregate(args); }
Calculates aggregate values for the data in a collection.