lets say we have an array of user ids :
"ids": [
"623d71c628820d09797be558",
"62419d6477775214de099838",
"62419d7877775214de099845",
"62419d8877775214de09984c"
]
and we want to return the first 10 documents of every id sorted by date. I know we can do :
const docs = await Model.find({ id: { $in: ids } })
.sort("date")
.limit(10);
which returns 10 documents sorted by date,but not for every user,how could i return 10 for every one in array ?
** EDIT **
Here's an example document from the balance collection:
{
"_id": "624a19a0b1cf7d69a5193737",
"user": {
"name": "john",
"id": "623d71c628820d09797be558"
},
"description": "chips",
"amount": 2,
"type": "expense",
"date": "2022-04-03T22:03:12.774Z",
"__v": 0
}
and a "user" document :
{
"_id": "623d71c628820d09797be558",
"name": "john",
"__v": 0
}
Here's one way you could do it using an aggregation pipeline.
db.collection.aggregate([
{
"$match": {
"id": {
"$in": [
"623d71c628820d09797be558",
"62419d6477775214de099838",
"62419d7877775214de099845",
"62419d8877775214de09984c"
]
}
}
},
{
"$sort": { "date": 1 }
},
{
"$group": {
"_id": "$id",
"docs": { "$push": "$$CURRENT" }
}
},
{
"$project": {
"_id": 0,
"id": "$_id",
"docs": { "$slice": [ "$docs", 10 ] }
}
}
])
Try it on mongoplayground.net.