Articles → MONGODB → $Project Aggregation Stage In Mongodb

$Project Aggregation Stage In Mongodb

In this article, we will discuss the $project aggregation stage in MongoDB.

Purpose

The $project aggregation stage is used to reshape the document. It does the reshaping using the following options: -

Including or excluding fields
Adding new fields
Modify existing fields

Example

Consider the following collection: -

Picture showing the sample document collection in mongodb

The below query includes adding a new field and modifying an existing field.

db.Employees.aggregate([
  {
    $project: {
     _id:1, // Include    
      fullname : {$concat: ["$firstname"," ", "$lastname"]},// adding a new field
     EmployeeAge: "$age" // Rename
      
    }
  }
])

Output

Posted By -	Karan Gupta

Posted On -	Monday, June 3, 2024

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