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How to find documents with child object that has matching value?

Suppose that I have a collection with documents like below
{
"location" : "Tokyo",
"region" : "Asia",
"attraction": {
"transportation" : "Subway",
"food" : {
"food_0" : {
"name" : "Sushi",
"price" : 100,
"restaurant" : "Ookinza"
},
"food_1" : {
"name" : "Sashimi",
"price" : 200,
"restaurant" : "Hibiki"
},
"food_2" : {
"name" : "N/A",
"price" : "N/A",
"restaurant" : "N/A"
}
}
}
},
{
"location" : "Taipei",
"region" : "Asia",
"attraction": {
"transportation" : "Subway",
"food" : {
"food_0" : {
"name" : "Bubble tea",
"price" : 50,
"restaurant" : "The Alley"
},
"food_1" : {
"name" : "Oyster cake",
"price" : 100,
"restaurant" : "Night market"
},
"food_2" : {
"name" : "N/A",
"price" : "N/A",
"restaurant" : "N/A"
}
}
}
},
{
"location" : "Toronto",
"region" : "North America",
"attraction": {
"transportation" : "Uber",
"food" : {
"food_0" : {
"name" : "Raman",
"price" : 300,
"restaurant" : "Kinto"
},
"food_1" : {
"name" : "Bubble tea",
"price" : 200,
"restaurant" : "Fresh Fruit"
},
"food_2" : {
"name" : "N/A",
"price" : "N/A",
"restaurant" : "N/A"
}
}
}
},
How do I find documents that have matching field in the child object of Food?
i.e. If I want to find document that has restaurant:"Fresh Tea"?
Currently what I have:
app.get(route, (req, res) => {
var detail = {};
if(req.query.location){
detail['location'] = req.query.location.toUpperCase();
}
if(req.query.region){
detail['region'] = req.query.region.toUpperCase();
}
if(req.query.transportation){
detail['attraction.transportation'] = new RegExp(req.query.transportation.split(","), "i"),
}
if(req.query.restaurant){
detail['attraction.food.food_0'] = req.query.restaurant;
}
db.collection(config.dbCollections.foodDB)
.aggregate([
$match: detail,
},
{
$lookup: {
... // code continues
Right now detail['attraction.food.food_0'] = req.query.restaurant is only able to find document that has matching food_0.restaurant, but I still can't find a way to make it check all child objects within "food".
Updated with more info:
User has the option to enter multiple search categories, and I want to combine all the search requests into "detail" and find all matching results. I.e. If user looks for transportation="Subway" and food="Bubble tea", then both Taipei and Toronto should come up as result.

Using dynamic value as field name is generally considered as anti-pattern and should be avoided. Nevertheless, you can convert the object attraction.food to an array of k-v tuple and perform the search with your criteria. For your case, $anyElementTrue with $map will help with processing the array.
db.collection.aggregate([
{
"$addFields": {
"test": {
"$anyElementTrue": {
"$map": {
"input": {
"$objectToArray": "$attraction.food"
},
"as": "t",
"in": {
$or: [
{
$eq: [
"$$t.v.transportation",
"Subway"
]
},
{
$eq: [
"$$t.v.name",
"Bubble tea"
]
}
]
}
}
}
}
}
},
{
$match: {
test: true
}
},
{
"$unset": "test"
}
])
Here is the Mongo Playground for your reference.

A possible aggregation pipeline
Add a temporary field using $addFields and $objectToArray which does something similar to javascript Object.entries()
Do the matching
Remove the added temporary field using $project 0
playground
db.collection.aggregate([
{
"$addFields": {
"foodArray": {
"$objectToArray": "$attraction.food"
},
},
},
{
"$match": {
"foodArray.v.restaurant": "Fresh Fruit"
}
},
{
"$project": {
"foodArray": 0
},
},
])

how to update document using aggregation

I have complex document I try to update using aggregate but it's only making copy when I use $out it's remove all other document I want to concate all other file to this and update........................................................................................................................................................................................................................................................................................................................................................................................................
db.getDb().collection(coll.seat).aggregate( [
{
'$unwind': {
'path': '$show_seats'
}
}, {
'$unwind': {
'path': '$show_seats.showByDate.shows'
}
}, {
'$unwind': {
'path': '$show_seats.showByDate.shows.showSeats'
}
}, {
'$unwind': {
'path': '$show_seats.showByDate.shows.showSeats'
}
}, {
'$unwind': {
'path': '$show_seats.showByDate.shows.showSeats.seat_details'
}
}, {
'$unwind': {
'path': '$show_seats.showByDate.shows.showSeats.seat_details.values'
}
}, {
'$match': {
'show_seats.showByDate.shows.showSeats.seat_details.values._id': ObjectId('62af61b72609bb5c0b664e7e')
}
}, {
'$addFields': {
'show_seats.showByDate.shows.showSeats.seat_details.values.seat_status': true
}
},
{
$out: 'shows'
}
])
this is my mongo db data look like
{
"_id" : ObjectId("62a43ac2d7213c7233cd1dee"),
"totalShowByDay" : "2",
"totalShowDays" : 4,
"movieId" : ObjectId("62953ba3cb6ae625ec9433e6"),
"screenId" : ObjectId("6293b9638dde2d92658d5513"),
"createdAt" : 1654930114438,
"showId" : ObjectId("62a43ac2d7213c7233cd14ed"),
"show_seats" : [
{
"showByDate" : {
"ShowDate" : "2022-06-11",
"shows" : [
{
"showTime" : "2022-06-11T10:00",
"showSeats" : [
[
{
"category" : "CLASSIC",
"seat_details" : [
{
"key" : "A",
"values" : [
{
"_id" : ObjectId("62a43ac2d7213c7233cd14ee"),
"seat_number" : "1",
"tag_name" : "A",
"seat_status" : false,
"user_id" : false,
"price" : "140",
"seats_category" : "CLASSIC",
"show_time" : "2022-06-11T10:00"
},
,
{
"_id" : ObjectId("62a43ac2d7213c7233cd14ef"),
"seat_number" : "2",
"tag_name" : "A",
"seat_status" : false,
"user_id" : false,
"price" : "140",
"seats_category" : "CLASSIC",
"show_time" : "2022-06-11T10:00"
},
{
"_id" : ObjectId("62a43ac2d7213c7233cd14f0"),
"seat_number" : "3",
"tag_name" : "A",
"seat_status" : false,
"user_id" : false,
"price" : "140",
"seats_category" : "CLASSIC",
"show_time" : "2022-06-11T10:00",,
{
"_id" : ObjectId("62a43ac2d7213c7233cd14ef"),
"seat_number" : "2",
"tag_name" : "A",
"seat_status" : false,
"user_id" : false,
"price" : "140",
"seats_category" : "CLASSIC",
"show_time" : "2022-06-11T10:00"
},
{
"_id" : ObjectId("62a43ac2d7213c7233cd14f0"),
"seat_number" : "3",
"tag_name" : "A",
"seat_status" : false,
"user_id" : false,
"price" : "140",
"seats_category" : "CLASSIC",
"show_time" : "2022-06-11T10:00"
}

How to group by sub documents and get unique value of value field?

This is my database collection:
{"productId" : 1,
"isVariant": 1,
"isComplete" : 1,
"variantId" : 1,
"attributeSet" : [
{
"name" : "Capacity",
"value" : "500 GB",
"id" : 3
},
{
"name" : "Form Factor",
"value" : "5 inch",
"id" : 4
},
{
"id" : 5,
"name" : "Memory Components",
"value" : "3D NAND",
"isVariation" : 0
}
]
},
{"productId" : 2,
"isVariant": 1,
"isComplete" : 1,
"variantId" : 1,
"attributeSet" : [
{
"name" : "Capacity",
"value" : "1 TB",
"id" : 3
},
{
"name" : "Form Factor",
"value" : "5 inch",
"id" : 4
},
{
"id" : 5,
"name" : "Memory Components",
"value" : "3D NAND",
"isVariation" : 0
}
]
},
{"productId" : 3,
"isVariant": 1,
"isComplete" : 0,
"variantId" : 1,
"attributeSet" : [
{
"name" : "Capacity",
"value" : "500 GB",
"id" : 3
},
{
"name" : "Form Factor",
"value" : "2.5 inch",
"id" : 4
},
{
"id" : 5,
"name" : "Memory Components",
"value" : "3D NAND",
"isVariation" : 0
}
]
},
{"productId" : 4,
"isVariant": 1,
"isComplete" : 0,
"variantId" : 1,
"attributeSet" : [
{
"name" : "Capacity",
"value" : "1 TB",
"id" : 3
},
{
"name" : "Form Factor",
"value" : "2.5 inch",
"id" : 4
},
{
"id" : 5,
"name" : "Memory Components",
"value" : "3D NAND",
"isVariation" : 0
}
]
}
Now I want to send the data of only the attribute where isVariation is not 0. Also I want to send the variant values of each attribute where isComplete =1. Hence the result should look like this
result : [{
"id": 3,
"name": "Capacity",
"value": [
"500 GB",
"1 TB"
]
}, {
"id": 4,
"name": "Form Factor",
"value": [
"5 inch"
]
}]
The above result does not have value of 2.5 inch as the isComplete is 0 for this document. Can anyone help me with the query

$match isComplete is 1
$project to show required fields
$unwind deconstruct attributeSet array
$match attributeSet.isVariation is not 0
$group by attributeSet.id and get first name and get unique value using $addToSet
db.collection.aggregate([
{ $match: { isComplete: 1 } },
{
$project: {
_id: 0,
attributeSet: 1
}
},
{ $unwind: "$attributeSet" },
{ $match: { "attributeSet.isVariation": { $ne: 0 } } },
{
$group: {
_id: "$attributeSet.id",
name: { $first: "$attributeSet.name" },
value: { $addToSet: "$attributeSet.value" }
}
}
])
Playground
The $project stage is not required in your query, i have added because this will optimize your query performance.

Mongodb $graphLookup build hierarchy [duplicate]

This question already has answers here:
MongoDB $graphLookup get children all levels deep - nested result
(2 answers)
Closed 3 years ago.
I have an output from mongodb $graphLookup aggregation:
db.getCollection('projects').aggregate([
{
$lookup: {
from: "projects",
localField: "_id",
foreignField: "parent",
as: "childrens"
}
}
])
{
"_id" : "1",
"name" : "Project1",
"parent" : null,
"childrens" : [
{
"_id" : "3",
"name" : "ProjectForId1",
"parent" : "1"
}
]
},
{
"_id" : "3",
"name" : "ProjectForId1",
"parent" : "1",
"childrens" : [
{
"_id" : "6",
"name" : "ProjectForId3",
"parent" : "3"
},
{
"_id" : "7",
"name" : "ProjectForId3",
"parent" : "3"
}
]
}
I need to build hierarchy from this output in javascript or if is possible directly from query so the final output should look like:
{
"_id" : "1",
"name" : "Project1",
"parent" : null,
"childrens" : [
{
"_id" : "3",
"name" : "ProjectForId1",
"parent" : "1",
"childrens" : [
{
"_id" : "6",
"name" : "ProjectForId3",
"parent" : "3"
},
{
"_id" : "7",
"name" : "ProjectForId3",
"parent" : "3"
}
]
}
]
}
Also if someone have a brave heart to help in one more case where the hierarchy will be created by filtering _id:
ex: For _id = "1" the output will be same as above but if _id is 3 the final output should look like:
{
"_id" : "3",
"name" : "ProjectForId1",
"parent" : "1",
"childrens" : [
{
"_id" : "6",
"name" : "ProjectForId3",
"parent" : "3"
},
{
"_id" : "7",
"name" : "ProjectForId3",
"parent" : "3"
}
]
}

Below solution is more or less the same as one of my past answers so you can get thorough explanation here
db.projects.aggregate([
{
$graphLookup: {
from: "projects",
startWith: "$_id",
connectFromField: "_id",
connectToField: "parent",
as: "children",
maxDepth: 4,
depthField: "level"
}
},
{
$unwind: "$children"
},
{
$sort: { "children.level": -1 }
},
{
$group: {
_id: "$_id",
children: { $push: "$children" }
}
},
{
$addFields: {
children: {
$reduce: {
input: "$children",
initialValue: {
currentLevel: -1,
currentLevelProjects: [],
previousLevelProjects: []
},
in: {
$let: {
vars: {
prev: {
$cond: [
{ $eq: [ "$$value.currentLevel", "$$this.level" ] },
"$$value.previousLevelProjects",
"$$value.currentLevelProjects"
]
},
current: {
$cond: [
{ $eq: [ "$$value.currentLevel", "$$this.level" ] },
"$$value.currentLevelProjects",
[]
]
}
},
in: {
currentLevel: "$$this.level",
previousLevelProjects: "$$prev",
currentLevelProjects: {
$concatArrays: [
"$$current",
[
{ $mergeObjects: [
"$$this",
{ children: { $filter: { input: "$$prev", as: "e", cond: { $eq: [ "$$e.parent", "$$this._id" ] } } } }
] }
]
]
}
}
}
}
}
}
}
},
{
$addFields: { children: "$children.currentLevelProjects" }
},
{
$match: {
_id: "1"
}
}
])
Last stage is supposed to be the filtering so you can get the data for any level of depth here.

Concatenate object's properties of variable length of a JavaScript object into a new property of the object

I have this complicated object structure:
myObject = {
"myObject" : [
{
"id" : 1,
"parameters" : [
{
"name" : "name1",
"special" : "xxx"
},
{
"name" : "name2",
"special" : "yyy"
}
]
},
{
"id" : 2,
"parameters" : [
{
"name" : "name3",
"special" : "zzz"
}
]
},
{
"id" : 2,
"parameters" : [
{
"name" : "name4",
"special" : "ttt"
},
{
"name" : "name5",
"special" : "aaa"
},
{
"name" : "name6",
"special" : "zzz"
}
]
},
...
]
};
It consists of a array of other objects, each of them having a variable number of parameters.
My goal is to concatenate the special of parameters of each object into a new string which must be stored as new property of it.
In this case, the result should look like:
myObject = {
"myObject" : [
{
"id" : 1,
"parameters" : [
{
"name" : "name1",
"special" : "xxx"
},
{
"name" : "name2",
"special" : "yyy"
}
],
"newProp" : "xxxyyy"
},
{
"id" : 2,
"parameters" : [
{
"name" : "name3",
"special" : "zzz"
}
],
"newProp" : "zzz"
},
{
"id" : 2,
"parameters" : [
{
"name" : "name4",
"special" : "ttt"
},
{
"name" : "name5",
"special" : "aaa"
},
{
"name" : "name6",
"special" : "zzz"
}
],
"newProp" : "tttaaazzz"
},
...
]
};
I tried something like this:
forEach(arr in myObject.myObject){
arr.parameters(forEach (i in arr.parameters.special) {
myObject.myObject = i.concat(myObject.myObject);
})
}
obviously, it does not work. But I guess that this could be the right approach.
Any suggestions?

You can loop through the object using Array#forEach and then construct the string based on parameter values using Array#map and Array#join, like this:
const myObject = {"myObject":[{"id":1,"parameters":[{"name":"name1","special":"xxx"},{"name":"name2","special":"yyy"}]},{"id":2,"parameters":[{"name":"name3","special":"zzz"}]},{"id":2,"parameters":[{"name":"name4","special":"ttt"},{"name":"name5","special":"aaa"},{"name":"name6","special":"zzz"}]}]};
myObject.myObject.forEach(item => {
item.newProp = item.parameters.map(p => p.special).join('');
});
console.log(myObject);

Use reduce and for Each
var myObject = {
"myObject" : [
{
"id" : 1,
"parameters" : [
{
"name" : "name1",
"special" : "xxx"
},
{
"name" : "name2",
"special" : "yyy"
}
]
},
{
"id" : 2,
"parameters" : [
{
"name" : "name3",
"special" : "zzz"
}
]
},
{
"id" : 2,
"parameters" : [
{
"name" : "name4",
"special" : "ttt"
},
{
"name" : "name5",
"special" : "aaa"
},
{
"name" : "name6",
"special" : "zzz"
}
]
}
]
};
myObject.myObject.forEach(arr => {
arr.prop = arr.parameters.reduce((res,obj)=> res+obj.special, '')
})
console.log(myObject)

You can use .map() and .reduce() like this:
let myObject = [{"id" : 1, "parameters" : [{ "name" : "name1", "special" : "xxx"}, { "name" : "name2", "special" : "yyy" }]}, { "id" : 2, "parameters" : [{ "name" : "name3", "special" : "zzz"}]}, {"id" : 2, "parameters" : [{ "name" : "name4", "special" : "ttt"}, { "name" : "name5", "special" : "aaa"},{ "name" : "name6", "special" : "zzz"}]}];
let result = myObject.map(
o => (o.newProp = o['parameters'].reduce((a, o) => a + o['special'], ""), o)
);
console.log(result);
.as-console-wrapper { max-height: 100% !important; top: 0; }

One more way is to use nested map functions:
myObject = {"myObject":[{"id":1,"parameters":[{"name":"name1","special":"xxx"},{"name":"name2","special":"yyy"}]},{"id":2,"parameters":[{"name":"name3","special":"zzz"}]},{"id":2,"parameters":[{"name":"name4","special":"ttt"},{"name":"name5","special":"aaa"},{"name":"name6","special":"zzz"}]}]};
myObject.myObject.map(x => {
x.newProp = x.parameters.map(p => p.special).join('');
return x;
})
console.log(myObject);