The fields to include.
The fields to include. The resulting objects will also contain these fields.
(addFields: StringAdd).self
(addFields: StringFormat).self
(addFields: ArrowAssoc[AggregationFramework.AddFields]).x
(Since version 2.10.0) Use leftOfArrow
instead
(addFields: Ensuring[AggregationFramework.AddFields]).x
(Since version 2.10.0) Use resultOfEnsuring
instead
Since MongoDB 3.4
The fields to include. The resulting objects will also contain these fields.
https://docs.mongodb.com/manual/reference/operator/aggregation/addFields/