Chapter 1: Basic Aggregation - $match and $project

Shaping documents with $project The correct answers are the following: Once we specify a field to retain or perform some computation in a $project stage, we must specify all fields we wish to retain. The only exception to this is the _id field. $project implicitly removes all other fields once we have retained, reshaped, or computed a new field. The exception to this is the _id field, which we m..

2021.02.03