Group based on multiple fields in a single query - mongodb

Question

I have the following document structure
[
{
"tag": "abc",
"created_at": 2020-02-05T14:20:52.907+00:00
"likes": 12,
"comments": 3
},
{
"tag": "abc",
"created_at": 2020-02-04T14:20:52.907+00:00
"likes": 10,
"comments": 1
}
{
"tag": "abc",
"created_at": 2020-01-04T14:21:52.907+00:00
"likes": 12,
"comments": 3
},
{
"tag": "abc",
"created_at": 2020-01-04T14:22:52.907+00:00
"likes": 2,
"comments": 1
}
]
First, I want to group my documents based on tag value and then on created_at field to get something like this.
[
{
"tag_name": "abc",
"day_wise": [
{
"dayMonthYear": "2020-01-04",
"comments": 4,
"likes": 14
},
{
"dayMonthYear": "2020-02-04",
"comments": 1,
"likes": 10
},
{
"dayMonthYear": "2020-02-05",
"comments": 3,
"likes": 12
},
],
"month_wise": [
{
"monthYear": "2020-04",
"comments": 5,
"likes": 24
},
{
"monthYear": "2020-05",
"comments": 3,
"likes": 12
},
],
}
]
There can be multiple tags so need to group them accordingly. Can anyone please suggest what aggregation query can be applied to achieve this result.

Answer 1

You can use below aggregation
db.collection.aggregate([
{ "$group": {
"_id": "$tag",
"data": {
"$push": {
"comments": "$comments",
"likes": "$likes",
"monthWise": { "$dateToString": { "date": "$created_at", "format": "%m-%Y" } },
"dateWise": { "$dateToString": { "date": "$created_at", "format": "%d-%m-%Y" } }
}
}
}},
{ "$project": {
"dateWise": {
"$map": {
"input": { "$setUnion": ["$data.dateWise"] },
"as": "m",
"in": {
"fieldA": "$$m",
"count": {
"$filter": {
"input": "$data",
"as": "d",
"cond": { "$eq": ["$$d.dateWise", "$$m"] }
}
}
}
}
},
"monthWise": {
"$map": {
"input": { "$setUnion": ["$data.monthWise"] },
"as": "m",
"in": {
"fieldA": "$$m",
"count": {
"$filter": {
"input": "$data",
"as": "d",
"cond": { "$eq": ["$$d.monthWise", "$$m"] }
}
}
}
}
}
}},
{ "$project": {
"dateWise": {
"$map": {
"input": "$dateWise",
"in": {
"dateWise": "$$this.fieldA",
"likes": { "$sum": "$$this.count.likes" },
"comments": { "$sum": "$$this.count.comments" }
}
}
},
"monthWise": {
"$map": {
"input": "$monthWise",
"in": { "monthWise": "$$this.fieldA",
"likes": { "$sum": "$$this.count.likes" },
"comments": { "$sum": "$$this.count.comments" }
}
}
}
}}
])
MongoPlayground

Answer 2

Try this one:
db.col.aggregate([
{
$facet:
{
day_wise: [
{
$group: {
_id: {
tag: "$tag",
day: { $dateFromParts: { year: { $year: "$created_at" }, month: { $month: "$created_at" }, day: { $dayOfMonth: "$created_at" } } }
},
likes: { $sum: "$likes" },
comments: { $sum: "$comments" }
}
},
{
$project: {
_id: "$_id.tag",
likes: 1,
comments: 1,
dayMonthYear: { $dateToString: { date: "$_id.day", format: "%Y-%m-%d" } },
day: "$_id.day"
}
}
],
month_wise: [
{
$group: {
_id: {
tag: "$tag",
month: { $dateFromParts: { year: { $year: "$created_at" }, month: { $month: "$created_at" } } }
},
likes: { $sum: "$likes" },
comments: { $sum: "$comments" }
}
},
{
$project: {
_id: "$_id.tag",
likes: 1,
comments: 1,
monthYear: { $dateToString: { date: "$_id.month", format: "%Y-%m" } },
month: "$_id.month"
}
}
],
tags: [{ $group: { _id: "$tag" } }]
}
},
{ $unwind: "$tags" },
{
$project: {
_id: "$tags._id",
day_wise: {
$filter: {
input: "$day_wise",
as: "item",
cond: { $eq: ["$tags._id", "$$item._id"] }
// here you can add additional conditions. e.g.
// { $gt: ["$day", { $subtract: ["$$NOW", 1000 * 60 * 60 * 5] }] } }
}
},
month_wise: {
$filter: {
input: "$month_wise",
as: "item",
cond: { $eq: ["$tags._id", "$$item._id"] }
}
}
}
},
{
$project: {
_id: 1,
day_wise: { likes: 1, comments: 1, dayMonthYear: 1 },
month_wise: { likes: 1, comments: 1, monthYear: 1 },
}
}
])
Mongo playground