Hello and Namaste everyone,

In this, we are talking about the lookup operation in MongoDB. Firstly, we understand the different fields we use in Lookup operations and then we perform it using an example. In the example, we are learning how to project the fields using $project while performing an aggregate operation $lookup.
It will help you to make you understand the basics of $lookup and $project in a pipeline.

Performs a left outer join to an unsharded collection in the same database to filter in documents from the “joined” collection for processing. To each input document, the $lookup stage adds a new array field whose elements are the matching documents from the “joined” collection. The $lookup stage passes these reshaped documents to the next stage.

how to join two collections in mongodb | lookup in mongodb
#mongodbLookUp #mongoProject #mongodbAggregation #lookupInCollection

#mongodb