Arithmetic Aggregation Operators in MongoDB

Arithmetic aggregation operators are used to perform mathematical calculations on numeric values in MongoDB aggregation pipelines. They are commonly used with stages such as $project, $addFields, and $group.

They are commonly used with stages such as $project, $set, $addFields, and $group.

Common Arithmetic Aggregation Operators

Example

Suppose we have:

db.emp.insertMany([
    { empnm: "Mital", salary: 25000, bonus: 5000 },
    { empnm: "Rahul", salary: 30000, bonus: 7000 }
])

1. $add — Addition

db.emp.aggregate([
    {
        $project: {
            empnm: 1,
            total: { $add: ["$salary", "$bonus"] }
        }
    }
])

Output:

Mital   30000
Rahul   37000

2. $subtract — Subtraction

db.emp.aggregate([
    {
        $project: {
            empnm: 1,
            salaryAfter: { $subtract: ["$salary", "$bonus"] }
        }
    }
])

3. $multiply — Multiplication

db.emp.aggregate([
    {
        $project: {
            empnm: 1,
            doubleSalary: { $multiply: ["$salary", 2] }
        }
    }
])

4. $divide — Division

db.emp.aggregate([
    {
        $project: {
            empnm: 1,
            halfSalary: { $divide: ["$salary", 2] }
        }
    }
])

5. $mod — Remainder

db.emp.aggregate([
    {
        $project: {
            result: { $mod: [17, 5] }
        }
    }
])

Output:

2

6. $pow — Power

db.emp.aggregate([
    {
        $project: {
            result: { $pow: [2, 4] }
        }
    }
])

Output:

16

In short

Arithmetic aggregation operators allow MongoDB to perform mathematical calculations directly inside an aggregation pipeline, reducing the need to calculate values in application code.