mongodb - aggregating and unwinding foreign ref documents - javascript

So for my example database set up:
db.lists.insertMany([
{ _id: "1", name: "list1", included_lists: ["2"], items: ["i1"] },
{ _id: "2", name: "list2", included_lists: [], items: ["i2", "i3"] }
])
db.items.insertMany([
{ _id: "i1", name: "item1", details: [{}, {}, {}] },
{ _id: "i2", name: "item2", details: [{}, {}, {}] },
{ _id: "i3", name: "item3", details: [{}, {}, {}] }
])
I'm currently getting my items data via:
db.lists.aggregate([
{ "$match": { "_id": { "$in": ["1", "2"] } } },
{
"$lookup": {
"from": "items",
"localField": "items",
"foreignField": "_id",
"as": "item"
}
},
{ "$unwind": "$item" },
{
"$facet": {
"results": [
{ "$skip": 0 },
{ "$limit": 10 },
{
"$project": {
name: 1,
item: 1
}
}
],
"total": [
{ "$count": "total" },
]
}
}
]).pretty()
which returns:
{
"results" : [
{
"_id" : "1",
"name" : "list1",
"item" : {
"_id" : "i1",
"name" : "item1",
"details" : [
{
},
{
},
{
}
]
}
},
{
"_id" : "2",
"name" : "list2",
"item" : {
"_id" : "i2",
"name" : "item2",
"details" : [
{
},
{
},
{
}
]
}
},
{
"_id" : "2",
"name" : "list2",
"item" : {
"_id" : "i3",
"name" : "item3",
"details" : [
{
},
{
},
{
}
]
}
}
],
"total" : [
{
"total" : 3
}
]
}
What I'm trying to do, is remove the { "$match": { "_id": { "$in": ["1", "2"] } } }, as I want to remove the query needed to get the array of ids, and instead just get all the ids from list _id and its included_lists ids. Then have return all the items return like my result.
This question is similar to: mongodb - unwinding nested subdocuments but I've reasked due to ambiguity and lack of db documents.

you can do it with graph lookup and then group
db.lists.aggregate([
{ "$match": { "_id": { "$in": ["1"] } } },
{
$graphLookup: {
from: "lists",
startWith: "$_id" ,
connectFromField: "included_lists",
connectToField: "_id",
as: "connected",
}
},
{$unwind:"$connected"},
{ $group:{_id:"$connected._id",items:{$first:'$connected.items'},name:{$first:'$connected.name'}}},
{
"$lookup": {
"from": "items",
"localField": "items",
"foreignField": "_id",
"as": "item"
}
},
{ "$unwind": "$item" },
{
"$facet": {
"results": [
{ "$skip": 0 },
{ "$limit": 10 },
{
"$project": {
name: 1,
item: 1
}
}
],
"total": [
{ "$count": "total" },
]
}
}
]).pretty()

Related

join object from another documnt with localfield key

i have a competition doc with field teams array of object with _id of team and a score doc with teamId field
competitions.teams = [{_id: 100,..}, {..}]
score.teamId = 100
when aggregatig score i want to group it to the competition teams but imm getting all team inside the group innstead of matching id
sample document https://mongoplayground.net/p/yJ34IBnnuf5
db.scores.aggregate([
{
"$match": {
"type": "league"
}
},
{
"$lookup": {
"from": "competitions",
"localField": "competitionId",
"foreignField": "_id",
"as": "comp"
}
},
{
"$unwind": {
"path": "$comp",
"preserveNullAndEmptyArrays": true
}
},
{
"$project": {
"comp.teams": 1,
"teamId": 1
}
},
{
"$group": {
"_id": "$teamId",
"results": {
"$push": "$comp.teams"
}
}
}
])
returns all team in group instead of matched teamid
{
"_id" : 100
"results" : [
{
"_id": 100,
"name": "team 1"
},
{
"_id": 101,
"name": "team 2"
}
]
}
{
"_id" 101
"results" : [
{
"_id": 100,
"name": "team 1"
},
{
"_id": 101,
"name": "team 2"
}
]
}
this is the result im trying to accomplish please guide me
{
"_id" : 100
"results" : [
{
"_id": 100,
"name": "team 1"
}
]
}
{
"_id" 101
"results" : [
{
"_id": 101,
"name": "team 2"
}
]
}
what should i do i've read the docs this seems to be the way?
Demo - https://mongoplayground.net/p/ETeroLftcZZ
You have to add $unwind: { "path": "$comp.teams" }
and after that group by { $group: { "_id": "$comp.teams._id" ... }
db.scores.aggregate([
{ $match: { "type": "league" } },
{ $lookup: { "from": "competitions", "localField": "competitionId", "foreignField": "_id", "as": "comp" } },
{ $unwind: { "path": "$comp", "preserveNullAndEmptyArrays": true } },
{ $unwind: { "path": "$comp.teams", "preserveNullAndEmptyArrays": true }},
{ $group: { "_id": "$comp.teams._id", "results": { $push: "$comp.teams" } } }
])
Demo with more data - https://mongoplayground.net/p/b41Ch5ge2Wp

How to add a condition inside $lookup in MongoDb .aggregate()?

persons collection:
{
"_id": ObjectId("5f3258cfbaaccedaa5dd2c96"),
"gender": "male",
"name": {
"title": "mr",
"first": "victor",
"last": "pedersen",//... more properties
}
persondetails collection:
{
"_id": ObjectId("5f3a91e68b1c26e68f9ed3ad"),
"country": "India",
"personid": ObjectId("5f3258cfbaaccedaa5dd2c96")
}
Get documents from persons along with associated persondetails where associated country in persondetails is "India
So if out of 10 persons only 3 are from India. I should get 3 person documents in resultset along with their associated persondetails
Query:
[
{
"$match": {
"$or": [
{
"$expr": {
"$eq": [
"$gender",
"male"
]
}
}
]
}
},
{
"$facet": {
"totalCount": [
{
"$count": "value"
}
],
"data": [
{
"$project": {
"_id": "$_id",
"fname": "$name.first",
"lname": "$name.last",
"dobage": "$dob.age",
"registeredAge": "$registered.age"
}
},
{
"$sort": {
"name.first": 1
}
} ,
{
"$lookup": {
"from": "persondetails",
"localField": "_id",
"foreignField": "personid", // how to add where clause in this lookup?
"as": "persondetail"
}
}
]
}
}
]
EDIT:
https://mongoplayground.net/p/3vBs6Frt-aK
Expected Result:
[
{
"data": [
{
"_id": ObjectId("5f3258cfbaaccedaa5dd2c96"),
"fname": "victor",
"lname": "pedersen",
"persondetail": [
{
"_id": ObjectId("5f3a91e68b1c26e68f9ed3ad"),
"country": "India",
"personid": ObjectId("5f3258cfbaaccedaa5dd2c96")
}
]
}],
"totalCount": [
{
"value": 1
}
]
}
]
There is a second $lookup syntax which allows you to specify custom filtering condition:
{
"$lookup": {
"from": "persondetails",
"let": { person_id: "$_id" },
"pipeline": [
{
$match: {
$expr: {
$and: [
{ $eq: [ "$$person_id", "$personid" ] },
{ $eq: [ "$country", "India" ] },
]
}
}
}
],
"as": "persondetail"
}
}
EDIT:
You also need to add $match to filter out people with empty persondetail and if you want this to be included in your count then you need to run $facet as the last operation:
[
{
"$match": {
"$or": [ {"$expr": { "$eq": [ "$gender", "male" ] } } ]
}
},
{
"$project": {
"_id": "$_id",
"fname": "$name.first",
"lname": "$name.last",
"dobage": "$dob.age",
"registeredAge": "$registered.age"
}
},
{
"$lookup": {
"from": "persondetails",
"let": { person_id: "$_id" },
"pipeline": [
{
$match: {
$expr: {
$and: [
{ $eq: [ "$$person_id", "$personid" ] },
{ $eq: [ "$country", "India" ] },
]
}
}
}
],
"as": "persondetail"
}
},
{
$match: {
persondetail: { $ne: [] }
}
},
{
$facet: {
totalCount: [ { $count: "value" } ],
data: [ { $sort: { "name.first": 1 } }, ]
}
}
]
Mongo Playground

How to change field from subdocument a parent field in Mongoose

I am trying to export Mongo data to XLSX which requires all the data to be in the parent map but currently I have data in this format:
[
{
"_id": "eatete",
"competition": {
"_id": "eatete"
"name": "Some competition name"
},
"members": [
{
"_id": "eatete",
"name": "Saad"
},
{
"_id": "eatete",
"name": "Saad2"
}
],
"leader": {
"name": "Saad",
"institute": {
"_id": "eatete",
"name": "Some institute name"
}
},
}
]
Ideally, the data should be:
[
{
"_id": "eatete",
"competition": "Some competition name"
"member0name": "Saad",
"member1name": "Saad2",
"leadername": "Saad",
"institute": "Some institute name"
}
]
So basically what I want is to refer the data of fields of subdocuments as if those were part of parent document, like competitions = competitions.name.
Can you please help me how can I do so using Mongoose.
Thanks
With some more aggregation trick
db.collection.aggregate([
{ "$unwind": { "path": "$members", "includeArrayIndex": "i" }},
{ "$group": {
"_id": "$_id",
"competition": { "$first": "$competition.name" },
"leadername": { "$first": "$leader.name" },
"institute": { "$first": "$leader.institute.name" },
"data": {
"$push": {
"k": { "$concat": ["members", { "$toLower": "$i" }, "name"] },
"v": "$members.name"
}
}
}},
{ "$replaceRoot": {
"newRoot": {
"$mergeObjects": ["$$ROOT", { "$arrayToObject": "$data" }]
}
}},
{ "$project": { "data": 0 }}
])
You can try below aggregation on your Model:
let resultt = await Model.aggregate([
{
$project: {
_id: 1,
competition: "$competition.name",
leadername: "$leader.name",
institute: "$leader.institute.name",
members: {
$map: {
input: { $range: [ 0, { $size: "$members" } ] },
in: {
k: { $concat: [ "member", { $toString: "$$this" }, "name" ] },
v: {
$let: {
vars: { current: { $arrayElemAt: [ "$members", "$$this" ] } },
in: "$$current.name"
}
}
}
}
}
}
},
{
$replaceRoot: {
newRoot: {
$mergeObjects: [ "$$ROOT", { $arrayToObject: "$members" } ]
}
}
},
{
$project: {
members: 0
}
}
])
Since you need to dynamically evaluate your keys based on indexes you can use $map with $range to map a list of indexes into keys of a new object. Then you can use $arrayToObject to get an object from those keys and $mergeObjects with $replaceRoot to flatten this object structure.

Trouble creating query in MongoDB with subquery

I have a dataset that looks something like this:
{
"id": "02741544",
"items": [{
"item": "A"
}]
}, {
"id": "02472691",
"items": [{
"item": "A"
}, {
"item": "B"
}, {
"item": "C"
}]
}, {
"id": "01316523",
"items": [{
"item": "A"
}, {
"item": "B"
}]
}, {
"id": "01316526",
"items": [{
"item": "A"
}, {
"item": "B"
}]
}, {
"id": "01316529",
"items": [{
"item": "A"
}, {
"item": "D"
}]
},
I'm trying to craft a query that will give me an output that looks like this:
{
"item": "A",
"ids": [{
"id": "02741544"
}, {
"id": "02472691"
}, {
"id": "01316523"
}, {
"id": "01316526"
}, {
"id": "01316529"
}]
}, {
"item": "B",
"ids": [{
"id": "02472691"
}, {
"id": "01316523"
}, {
"id": "01316526"
}]
}, {
"item": "C",
"ids": [{
"id": "02472691"
}]
}, {
"item": "D",
"ids": [{
"id": "02472691"
}]
},
Basically, I'm trying to get the distinct items from the item array in the object, and then returning an array of ids for each obj that has that item in it's item array.
Better use the aggregation framework in which you need to run an operation that consists of the following pipeline steps (in the given order):
$unwind - This initial step will flatten the items array i.e. it produces a copy of each document per array entry. This is necessary for processing the documents further down the pipeline as "denormalised" documents which you can aggregate as groups.
$group - This will group the flattened documents by the item subdocument key and create the ids list by using the $push accumulator operator.
-- UPDATE --
As #AminJ pointed out in the comments, if items can have duplicate item values and you don't want duplicate ids in the result you can use $addToSet instead of $push
The following example demonstrates this:
db.collection.aggregate([
{ "$unwind": "$items" },
{
"$group": {
"_id": "$items.item",
"ids": {
"$push": { "id": "$id" } /* or use
"$addToSet": { "id": "$id" } if you don't want duplicate ids */
}
}
}
])
Sample Output
{
"_id" : "A",
"ids" : [
{ "id" : "02741544" },
{ "id" : "02472691" },
{ "id" : "01316523" },
{ "id" : "01316526" },
{ "id" : "01316529" }
]
}
/* 2 */
{
"_id" : "B",
"ids" : [
{ "id" : "02472691" },
{ "id" : "01316523" },
{ "id" : "01316526" }
]
}
/* 3 */
{
"_id" : "C",
"ids" : [
{ "id" : "02472691" }
]
}
/* 4 */
{
"_id" : "D",
"ids" : [
{ "id" : "01316529" }
]
}
The result from an aggregate() function is a cursor to the documents produced by the final stage of the aggregation pipeline operation. So if you want the results in an array you can use the cursor's toArray() method which returns an array that contains all the documents from it.
For example:
var pipeline = [
{ "$unwind": "$items" },
{
"$group": {
"_id": "$items.item",
"ids": {
"$push": { "id": "$id" } /* or use
"$addToSet": { "id": "$id" } if you don't want duplicate ids */
}
}
}
],
results = db.collection.aggregate(pipeline).toArray();
printjson(results);
Here's a solution using an aggregation pipeline:
db.col.aggregate([
{
$unwind: "$items"
},
{
$project: {
id: 1,
item: "$items.item"
}
},
{
$group: {
_id: "$item",
ids: {
$push: "$id"
}
}
}
])

MongoDB nested query - BadValue error

Here's the query I'm trying to run:
{ ownerId: 14,
'$or':
[ { '$or':
[ { '$and':
[ { provider: 'INSTAGRAM' },
{ tags:
{ '$or':
[ { '$in': [ 'skyhotel' ] },
{ '$or': [ { '$all': ["skyhotel","excellent"] } ] } ] } } ] },
{ '$and':
[ { provider: 'VKONTAKTE' },
{ tags:
{ '$or':
[ { '$in': [ 'skyhotel' ] },
{ '$or': [ { '$all': ["skyhotel","excellent"] } ] } ] } } ] } ] },
{ '$or':
[ { '$and':
[ { provider: 'INSTAGRAM' },
{ authorLogin: { '$in': [ 'valera92', 'petyan' ] } } ] },
{ '$and':
[ { provider: 'VKONTAKTE' },
{ authorLogin: { '$in': [ 'valera92' ] } } ] } ] },
{ '$or':
[ { '$and':
[ { provider: 'INSTAGRAM' },
{ locationId: { '$in': [ '32454234' ] } } ] } ] },
{ '$or':
[ { '$and':
[ { provider: 'INSTAGRAM' },
{ location: { '$or': [ { '$geoWithin': { '$centerSphere': [ [ '56.829782', '60.593162' ], 0.000012629451881788331 ] } } ] } } ] } ] } ] }
It seems to be malformed according to mongo standards. The error I'm getting is:
Can't canonicalize query: BadValue unknown operator: $or
What would be the proper way in which I could reformat this query?
EDIT: Document example
{
"_id" : ObjectId("570362332ee1a7ab1ecb9899"),
"proextid" : "INSTAGRAM_fdfsfsdfsdfwefwef2r3232",
"updatedAt" : ISODate("2016-04-05T06:58:59.683Z"),
"createdAt" : ISODate("2016-04-05T06:58:59.683Z"),
"ownerId" : 7,
"authorId" : "390599885",
"authorName" : "name",
"authorLogin" : "login",
"authorDetail" : {
"authorPicture" : "url",
"authorLink" : "url"
},
"externalCreatedAt" : ISODate("2015-08-29T22:42:04.000Z"),
"externalId" : "fdsfsdfsdfsdfwer2342342423423r23r",
"detailType" : "PHOTO",
"location" : [
0,
0
],
"locationId" : "",
"locationTitle" : "",
"provider" : "INSTAGRAM",
"detail" : {},
"description" : "hello",
"tags" : [
"ленинградскийпроспект",
"москва",
"архитектура",
"историческоенаследие",
"петровскийдворец"
],
"commentsCount" : 1,
"likesCount" : 40,
"groupName" : "",
"__v" : 0
}
Your query could be simplified as something like:
{
ownerId:14,
provider: { $in: [ 'INSTAGRAM', 'VKONTAKTE' ] },
'$or': [
{
tags: { $in: [ 'skyhotel', 'excellent' ] }
},
{
authorLogin: { $in: [ 'valera92', 'petyan' ] },
},
{
locationId:{ '$in':[ '32454234' ] }
},
{
location:{
{
'$geoWithin':{
'$centerSphere':[ [ '56.829782', '60.593162' ], 0.000012629451881788331 ]
}
}
}
}
]
}
Now this may not be exactly what you're looking for. But from what you asked, and the information you provided, this is the best suggestion I can give.

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