MongoDB $sqrt Operator

MongoDB provides different types of arithmetic expression operators that are used in the aggregation pipeline stages $sqrt operator is one of them. This operator is used to find the square root of a positive number and returns the result as a double.

Syntax: 

{ $sqrt: <number> }

Here, the number is a valid expression until it resolves to a non-negative number. 

• If the entered value is null, then this operator will return null.
• If the entered value is NaN, then this operator will return NaN.
• If the entered value is a missing field, then this operator will return null.

Examples:

In the following examples, we are working with:

Database: GeeksforGeeks

Collection: example

Document: two documents that contain the details of the shapes in the form of field-value pairs.

Finding the square root of the field using $sqrt operator:

In this example, we are going to find the square root of the value of the side field in the Square document using $sqrt operator.

db.example.aggregate([{$match:{name: "Square"}},
... {$project: {squareRoot: {$sqrt: "$side"}}}])

Finding the square root of the field in the embedded document using $sqrt operator:

In this example, we are going to find the square root of the sum of the values of the measurement.height and measurement.width fields in the Rectangle document using $sqrt operator.

db.example.aggregate([{$match:{name: "Rectangle"}},
... {$project: {squareRoot: {$sqrt:{$add: ["$measurement.height",
                                          "$measurement.width"]}}}}])