$range
The $range operator allows generating an array of sequential integers.
$range
The $range operator is used to generate an array of sequential integers. The operator helps create number arrays in a range, useful for pagination, indexing, or test data.
Parameters
| Parameter | Description |
|---|---|
start | The starting value of the range (inclusive). |
end | The ending value of the range (exclusive). |
step | The increment value between each number in the range (optional, defaults to 1). |
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: Generate a range of numbers
This query demonstrates usage of operator to generate an array of integers from 0 to 5, wherein it includes the left boundary while excludes the right.
db.stores.aggregate([{
$match: {
_id: "a715ab0f-4c6e-4e9d-a812-f2fab11ce0b6"
}
}, {
$project: {
rangeArray: {
$range: [0, 5]
}
}
}])This query returns the following result.
[
{
"_id": "a715ab0f-4c6e-4e9d-a812-f2fab11ce0b6",
"rangeArray": [
0,
1,
2,
3,
4
]
}
]Example 2: Generate a range of numbers with a step value
This query demonstrates usage of operator to generate an array of even numbers from 0 to 18.
db.stores.aggregate([{
$match: {
_id: "a715ab0f-4c6e-4e9d-a812-f2fab11ce0b6"
}
}, {
$project: {
evenNumbers: {
$range: [0, 8, 2]
}
}
}])This query results the following result.
[
{
"_id": "a715ab0f-4c6e-4e9d-a812-f2fab11ce0b6",
"rangeArray": [
0,
2,
4,
6
]
}
]