MongoDB query to sum specific fields

To sum specific fields, use aggregate along with $sum. Let us first create a collection with documents −

> db.getSumOfFieldsDemo.insertOne({"Customer_Id":101,"Price":50,"Status":"Active"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e06cec29e4dae213890ac55")
}
> db.getSumOfFieldsDemo.insertOne({"Customer_Id":102,"Price":200,"Status":"Inactive"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e06ced19e4dae213890ac56")
}
> db.getSumOfFieldsDemo.insertOne({"Customer_Id":101,"Price":3000,"Status":"Active"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e06cedd9e4dae213890ac57")
}
> db.getSumOfFieldsDemo.insertOne({"Customer_Id":103,"Price":400,"Status":"Active"});
{
   "acknowledged" : true,
   "insertedId" : ObjectId("5e06cee79e4dae213890ac58")
}

Following is the query to display all documents from a collection with the help of find() method −

> db.getSumOfFieldsDemo.find().pretty();

This will produce the following output −

{
   "_id" : ObjectId("5e06cec29e4dae213890ac55"),
   "Customer_Id" : 101,
   "Price" : 50,
   "Status" : "Active"
}
{
   "_id" : ObjectId("5e06ced19e4dae213890ac56"),
   "Customer_Id" : 102,
   "Price" : 200,
   "Status" : "Inactive"
}
{
   "_id" : ObjectId("5e06cedd9e4dae213890ac57"),
   "Customer_Id" : 101,
   "Price" : 3000,
   "Status" : "Active"
}
{
   "_id" : ObjectId("5e06cee79e4dae213890ac58"),
   "Customer_Id" : 103,
   "Price" : 400,
   "Status" : "Active"
}

Following is the query to sum specific fields based on ACTIVE status −

> db.getSumOfFieldsDemo.aggregate([ { $match: { Status: "Active" } }, { $group: { _id: "$Customer_Id", TotalSum: { $sum: "$Price" } } } ]);

This will produce the following output −

{ "_id" : 103, "TotalSum" : 400 }
{ "_id" : 101, "TotalSum" : 3050 }