Question

How do you add new fields in the $project stage?

Answer 1

To add new fields in the $project stage, use the $addFields operator in MongoDB's aggregation framework. This operator allows you to add new fields to the documents being processed.

Step-by-step explanation:

To add new fields in the $project stage, you can use the $addFields operator in MongoDB's aggregation framework. This operator allows you to add new fields to the documents being processed. Here's an example:

{ $addFields: { newField: "$existingField" } }

In this example, a new field called 'newField' is added to each document, and its value is set to the value of an existing field called 'existingField'.