Novo na versão 4.0:https://docs.mongodb.com/manual/reference/operator/aggregation/toObjectId/
// Define stage to add convertedId field with converted _id value
idConversionStage = {
$addFields: {
convertedId: { $toObjectId: "$_id" }
}
};
// Define stage to sort documents by the converted qty values
sortStage = {
$sort: { "convertedId": -1 }
};
db.orders.aggregate( [
idConversionStage,
sortStage
])
