abs Function in MongoDB

In MongoDB, there isn't a built-in ABS function like in SQL databases. However, you can achieve similar functionality using the $abs operator in aggregation pipelines.

Here's an example:

Suppose you have a collection named numbers with documents containing numeric values:

{ "_id": 1, "value": -10 }

{ "_id": 2, "value": 20 }

{ "_id": 3, "value": -5 }

To get the absolute value of the value field for each document, you can use the $abs operator in an aggregation pipeline like this:

db.numbers.aggregate([

  {

    $project: {

      absoluteValue: { $abs: "$value" }

    }

  }

])

This aggregation pipeline will produce the following result:

{ "_id": 1, "absoluteValue": 10 }

{ "_id": 2, "absoluteValue": 20 }

{ "_id": 3, "absoluteValue": 5 }

It calculates the absolute value of the value field for each document and includes it in the output as absoluteValue.