$percentile
The $percentile operator calculates the percentile of numerical values that match a filtering criteria
$percentile
The $percentile operator calculates the percentile of numerical values that match a filtering criteria. This operator is particularly useful for identifying statistical thresholds, such as median or percentiles.
Syntax
$percentile: {
input: < field or expression > ,
p: [ < percentile values > ],
method: < method >
}Parameters
| Parameter | Description |
|---|---|
input | Specifies the numerical data to calculate the percentile from. |
p | An array of percentile values (between 0 and 1) to calculate. |
method | Specifies the interpolation method to use. Valid values are "approximate" and "continuous". |
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: Calculate the 50th percentile of sales volume
This query calculates the 50th percentile (median) of total sales volume within each sales category across all stores.
db.stores.aggregate([{
$unwind: "$sales.salesByCategory"
},
{
$group: {
_id: null,
medianSales: {
$percentile: {
input: "$sales.salesByCategory.totalSales",
p: [0.5],
method: "approximate"
}
}
}
}
])This query returns the following result:
[
{
"_id": null,
"medianSales": [
25070.449624139295
]
}
]Example 2: Calculate multiple percentiles
This query calculates the 25th, 50th, and 75th percentiles of the total sales across all stores.
db.stores.aggregate([{
$group: {
_id: null,
percentiles: {
$percentile: {
input: "$sales.fullSales",
p: [0.25, 0.5, 0.75],
method: "approximate"
}
}
}
}])This query returns the following result:
[
{
"_id": null,
"percentiles": [
3700,
3700,
3700
]
}
]