$floor (arithmetic expression)

APPLIES TO: MongoDB vCore

The $floor operator returns the largest integer less than or equal to the specified number.

Syntax

The syntax for the $floor operator is as follows:

{ $floor: <number> }

Parameters

Description
<number> Any valid expression that resolves to a number.

Example

Let's understand the usage with sample data from the stores dataset to calculate floor values of average sales and discounts.

db.stores.aggregate([
  { $match: { "_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74" } },
  {
    $project: {
      name: 1,
      averageSalesFloor: {
        $floor: {
          $divide: [
            "$sales.totalSales",
            { $size: "$sales.salesByCategory" }
          ]
        }
      },
      categoriesWithFloorSales: {
        $map: {
          input: "$sales.salesByCategory",
          as: "category",
          in: {
            categoryName: "$$category.categoryName",
            floorSales: { $floor: "$$category.totalSales" }
          }
        }
      }
    }
  }
])

This will produce the following output:

{
  "_id": "40d6f4d7-50cd-4929-9a07-0a7a133c2e74",
  "name": "Proseware, Inc. | Home Entertainment Hub - East Linwoodbury",
  "averageSalesFloor": 30372,
  "categoriesWithFloorSales": [
    {
      "categoryName": "Sound Bars",
      "floorSales": 2120
    },
    {
      "categoryName": "Home Theater Projectors",
      "floorSales": 45004
    },
    {
      "categoryName": "Game Controllers",
      "floorSales": 43522
    },
    {
      "categoryName": "Remote Controls",
      "floorSales": 28946
    },
    {
      "categoryName": "VR Games",
      "floorSales": 32272
    }
  ]
}

Related content