MongoDB Generate Group query based on the keyword - mongodb

Question

I am trying to create top 10 product list based on postType = "buy". My logic is a count postType = "buy" and sort the top 10 products from the logs collection. Here are my sample log collections.
[
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "buy",
"product": "3",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "view",
"product": "4",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "buy",
"product": "2",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "view",
"product": "2",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "share",
"product": "3",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "buy",
"product": "2",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "buy",
"product": "2",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "share",
"product": "2",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "buy",
"product": "1",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "buy",
"product": "1",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "viewvideo",
"product": "1",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "viewvideo",
"product": "2",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "viewvideo",
"product": "3",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "buy",
"product": "4",
},
{
"_id": "633dc5b761ff04e7ae8e8c0f",
"postType": "buy",
"product": "5",
}
]
I am trying to get count for totalBuybutton, totalShareButton, totalView if 'buy' keyword matched.
My expected output is:
[
{"product":1, "totalBuycount":2, "shareButtonCount":4, viewCount":4},
{"product":2, "totalBuycount":3, shareButtonCount":4, viewCount":4},
{"product":3, "totalBuycount":1, shareButtonCount":4, viewCount":4},
{"product":4, "totalBuycount":1, shareButtonCount":4, viewCount":4},
{"product":5, "totalBuycount":1, shareButtonCount":2, viewCount":4}
]
My current implementation is as below
aggregate([
{
$match: {
postType: "buybutton"
},
},
{
$group: {
_id: "$product",
count: {
$count: {}
}
}
},
{
$project: {
product: "$_id",
count: 1,
_id: 0,
},
},)

Answer 1

No idea, if this is what you are looking for.
The main part is
{
$group: {
_id: { postType: "$postType", product: "$product" },
count: { $count: {} }
}
}
Do you really need exactly the output as given in the question. It would require quite a lot of cosmetic work
db.collection.aggregate([
{
$group: {
_id: { postType: "$postType", product: "$product" },
count: { $count: {} }
}
},
{
$group: {
_id: "$_id.product",
data: { $push: "$$ROOT" }
}
},
{
$project: {
_id: 0,
product: "$_id",
data: {
$arrayToObject: {
$map: {
input: "$data", in: {
k: "$$this._id.postType", v: "$$this.count",
}
}
}
}
}
},
{ $replaceWith: { $mergeObjects: ["$$ROOT", "$data"] } },
{ $unset: "data" }
])
]
{ product: '5', buy: 1 },
{ product: '3', buy: 1, share: 1, viewvideo: 1 },
{ product: '2', buy: 3, view: 1, viewvideo: 1, share: 1 },
{ product: '1', viewvideo: 1, buy: 2 },
{ product: '4', buy: 1, view: 1 }
]
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