reactivemongo.api.commands.AggregationFramework
$groups documents together to calculate aggregates on document collections .
This command aggregates on arbitrary identifiers. Document fields identifier must be prefixed with $.
$
any BSON value acceptable by mongodb as identifier
the sequence of operators specifying aggregate calculation
$groups documents together to calculate aggregates on document collections .
This command aggregates on arbitrary identifiers. Document fields identifier must be prefixed with
$
.