Question

T or F: The requested fields to be forwarded to the next stage after $project must be existing fields from the input documents.

Answer 1

The statement is false; the $project stage in MongoDB can be used to include new computed fields that do not exist in the original input documents.

Step-by-step explanation:

The statement is False. In MongoDB, when using the $project stage of an aggregation pipeline, you are not limited to only existing fields from the input documents. $project can be used to include, exclude, or add new fields that are not necessarily present in the input documents. It does this by creating computed fields using expressions that can transform the data. For example, you could use $project to add a field that calculates the total cost by multiplying a quantity field by a price field, even if the total cost field did not exist in the original document.