$sortArray

The $sortArray operator is used to sort the elements of an array. The operator can be useful when you need to sort arrays within your documents based on specific fields or criteria. It can be applied to arrays of embedded documents or simple arrays of values.

Syntax

{
  $sortArray: {
    input: <arrayExpression>,
    sortBy: <sortSpecification>
  }
}

Parameters

Parameter Description
input The array to be sorted.
sortBy Specifies the sort order. It can be a single field or multiple fields with their corresponding sort order (1 for ascending, -1 for descending).

Examples

Consider this sample document from the stores collection.

{
    "_id": "0fcc0bf0-ed18-4ab8-b558-9848e18058f4",
    "name": "First Up Consultants | Beverage Shop - Satterfieldmouth",
    "location": {
        "lat": -89.2384,
        "lon": -46.4012
    },
    "staff": {
        "totalStaff": {
            "fullTime": 8,
            "partTime": 20
        }
    },
    "sales": {
        "totalSales": 75670,
        "salesByCategory": [
            {
                "categoryName": "Wine Accessories",
                "totalSales": 34440
            },
            {
                "categoryName": "Bitters",
                "totalSales": 39496
            },
            {
                "categoryName": "Rum",
                "totalSales": 1734
            }
        ]
    },
    "promotionEvents": [
        {
            "eventName": "Unbeatable Bargain Bash",
            "promotionalDates": {
                "startDate": {
                    "Year": 2024,
                    "Month": 6,
                    "Day": 23
                },
                "endDate": {
                    "Year": 2024,
                    "Month": 7,
                    "Day": 2
                }
            },
            "discounts": [
                {
                    "categoryName": "Whiskey",
                    "discountPercentage": 7
                },
                {
                    "categoryName": "Bitters",
                    "discountPercentage": 15
                },
                {
                    "categoryName": "Brandy",
                    "discountPercentage": 8
                },
                {
                    "categoryName": "Sports Drinks",
                    "discountPercentage": 22
                },
                {
                    "categoryName": "Vodka",
                    "discountPercentage": 19
                }
            ]
        },
        {
            "eventName": "Steal of a Deal Days",
            "promotionalDates": {
                "startDate": {
                    "Year": 2024,
                    "Month": 9,
                    "Day": 21
                },
                "endDate": {
                    "Year": 2024,
                    "Month": 9,
                    "Day": 29
                }
            },
            "discounts": [
                {
                    "categoryName": "Organic Wine",
                    "discountPercentage": 19
                },
                {
                    "categoryName": "White Wine",
                    "discountPercentage": 20
                },
                {
                    "categoryName": "Sparkling Wine",
                    "discountPercentage": 19
                },
                {
                    "categoryName": "Whiskey",
                    "discountPercentage": 17
                },
                {
                    "categoryName": "Vodka",
                    "discountPercentage": 23
                }
            ]
        }
    ]
}

Example 1: Sorting an Array of Embedded Documents

This query sorts the sales.salesByCategory array within each document in descending order based on totalSales.

db.stores.aggregate([{
    $match: {
        _id: "d3c9df51-41bd-4b4e-a26b-b038d9cf8b45"
    }
}, {
    $project: {
        sortedSalesByCategory: {
            $sortArray: {
                input: "$sales.salesByCategory",
                sortBy: {
                    totalSales: -1
                }
            }
        }
    }
}])

This query returns the following result.

[
    {
        "_id": "d3c9df51-41bd-4b4e-a26b-b038d9cf8b45",
        "sortedSalesByCategory": [
            {
                "categoryName": "DJ Accessories",
                "totalSales": 60000
            },
            {
                "categoryName": "Music Accessories",
                "totalSales": 40000
            },
            {
                "categoryName": "DJ Speakers",
                "totalSales": 36972
            },
            {
                "categoryName": "DJ Headphones",
                "totalSales": 12877
            }
        ]
    }
]

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