In MongoDB 5.2, there is a function called $firstN
. Is there any alternate function or any other way to find the first n elements from a given array in MongoDB 4.2?
Sample document:
{
"id": 1234,
"products": [
{
"productId": 111,
"path": "H"
},
{
"productId": 112,
"path": "H"
},
{
"productId": 113,
"path": "P"
}
]
}
I want to return the first n product objects from the product array.
With MongoDB 5.2, I can solve this Mongo playground.
Use $slice
operator with a similar functionality to take the nth element.
db.collection.aggregate([
{
"$project": {
"firstFiveProducts": {
"$slice": [
"$products",
5
]
}
}
}
])