Structure:
[
{
"_id": "12",
"title": "Vanella Icream",
"contain":"sugar",
"details": [
{
"flavour": "Vanella"
},
{
"weight": "6KG"
}
]
},
{
"_id": "3",
"title": "Pretzels",
"contain":"salt",
"details": [
{
"flavour": "Wheat"
},
{
"weight": "2KG"
}
]
}
]
Expected Output
details:
{
"flavour": [
"Vanella",
"Wheat",
],
"weight": [
"6KG",
"2KG",
]
}
More Important: I've to do this without details.flavour or details.weight.
I’ve tried with $addToSet, $filter $group but I’m not getting results like that. anyone please suggest.
Mongo Playground: https://mongoplayground.net/p/SXw3jaRDzLy
$project to show required field$unwind deconstruct the details array$objectToArray convert details object to array key-value format$unwind deconstruct the details array$group by details key and construct the array of values$group by null and construct the array of details in key-value format$arrayToObject convert above result from key-value format array of object to an objectdb.collection.aggregate([
{
$project: {
_id: 0,
details: 1
}
},
{ $unwind: "$details" },
{
$project: {
details: { $objectToArray: "$details" }
}
},
{ $unwind: "$details" },
{
$group: {
_id: "$details.k",
v: { $addToSet: "$details.v" }
}
},
{
$group: {
_id: null,
details: {
$push: { k: "$_id", v: "$v" }
}
}
},
{
$project: {
_id: 0,
details: { $arrayToObject: "$details" }
}
}
])