Develop Reference

Mongoose, updated nested array

My question is:
How can I query in the nested arrays?
I want to change value in key "likeUp" which is nested inside object in array "usersWhoLiked". Where "usersWhoLiked" is nested in array "comments"
How Can I do that with mongoose ?
Request that I wrote beneath... do not work, but is very similar to answer given in StackOverflow post: Mongoose update update nested object inside an array
This is my request to db with updateOne:
try {
const response = await Comments.updateOne(
{
productId,
comments: { $elemMatch: { usersWhoLiked: { $elemMatch: { userId } } } },
},
{
$set: { 'comments.$[outer].usersWhoLiked.$[inner].likeUp': likes.up },
},
{
arrayFilters: [{ 'outer._id': commentId }, { 'inner._userId': userId }],
}
).exec();
return res.status(201).json({ response });
} catch (err) {
console.log(err);
return res.send(err);
}
This is the collection, that I am trying to update:
{
"_id": {
"$oid": "6307569d2308b78b378cc802"
},
"productId": "629da4b6634d5d11a859d729",
"comments": [
{
"userId": "62f29c2c324f4778dff443f6",
"userName": "User",
"date": "2022.08.25",
"confirmed": true,
"likes": {
"up": 0,
"down": 0
},
"content": {
"rating": 5,
"description": "Nowy komentarz"
},
"_id": {
"$oid": "630756b22308b78b378cc809"
},
"usersWhoLiked": [
{
"userId": "62f29c2c324f4778dff443f1",
"likeUp": true,
"_id": {
"$oid": "6307572d2308b78b378cc80e"
}
},
{
"userId": "62f29c2c324f4778dff443f2",
"likeUp": true,
"_id": {
"$oid": "6307572d2308b78b378cc80c"
}
}
]
}
],
"__v": 0
}
Mongooes schema for comment collection:
const commentSchema = new Schema({
productId: String,
comments: [
{
userId: String,
userName: String,
date: String,
confirmed: Boolean,
likes: {
up: {
type: Number,
default: 0,
},
down: {
type: Number,
default: 0,
},
},
content: {
rating: Number,
description: String,
},
usersWhoLiked: [{ userId: String, likeUp: Boolean }],
},
],
});

I guess the problem is with your arrayFilters operator, because you are trying to filter by field _userId which does not exist:
arrayFilters: [{ 'outer._id': commentId }, { 'inner._userId': userId }],
I managed to update the likeUp value using the following query:
db.collection.update({
_id: ObjectId("6307569d2308b78b378cc802")
},
{
$set: {
"comments.$[user].usersWhoLiked.$[like].likeUp": false
}
},
{
arrayFilters: [
{
"user._id": ObjectId("630756b22308b78b378cc809")
},
{
"like.userId": "62f29c2c324f4778dff443f1"
}
]
})
Try it on MongoDB playground: https://mongoplayground.net/p/XhQMNBgEdhp

MongooseJS: How to remove 1 object inside Array in Array of Objects

Hi MongooseJS experts!
I'm new in MongooseJS, This is my 2nd day of solving this problem but I can't find a working solution to this.
Thank you in advance!
My Delete method
Cart.updateOne(
{ "content.merchantId": req.body.merchantId },
{ $pull: { "content.items._id": req.body.productId } },
{ new: true },
function (error, result) {
if (error) { }
else if (result) { }
}
);
Schema
const CartSchema = new Schema({
customerId: {
type: String,
required: true,
},
content: {
merchantName: {
type: String,
required: true,
},
merchantId: {
type: String,
required: true,
},
items: [],
},
});
Sample JSON
[
{
"content": {
"merchantName": "SAMPLE_MERCHANT_NAME",
"merchantId": "SAMPLE_MERCHANT_ID",
"items": [
{
"_id": "SAMPLE_ID",
"title": "SAMPLE TITLE",
}
]
},
"_id": "618220e83966345ab5d451cd",
"__v": 0
},
]
Error message
Cannot use the part (_id) of (content.items._id) to traverse the element ({items: [{ _id: "SAMPLE_ID", title: "SAMPLE TITLE"}] })

you should use like this
db.collection.update({
"content.merchantId": "SAMPLE_MERCHANT_ID"
},
{
$pull: {
"content.items": {
"_id": "SAMPLE_ID"
}
}
},
{
new:true
},
)
https://mongoplayground.net/p/Ou26tab2mBU

Filter nested of nested in Mongoose Populate

I have an object that looks like this: (that is the output of Mongoose query)
let systems = [
{
"maxUserLevel": 1,
"subsystems": [
{
"sections": [],
"name": "apple"
},
{
"sections": [
{
"name": "banana"
}
],
"name": "sun",
},
{
"sections": [],
"name": "orange"
}
],
"systemID": "12345"
},
{
"maxUserLevel": 3,
"subsystems": [
{
"sections": [],
"name": "blue"
},
{
"sections": [
{
"name": "pink"
}
],
"name": "red",
},
],
"systemID": "15654"
}];
The Mongoose query:
this.model.System.find({username: user.username}, {
_id: 0,
allowedOrganizations: 0,
name: 0,
updatedAt: 0,
createdAt: 0,
versionKey: 0
})
.populate(
{
path: "subsystems",
populate: {
path: "sections",
select: "name -_id",
match: {
allowedUsers: user.id
}
},
select: "name metadata -_id",
}
)
.exec((error, systems) => {
return res.status(200).json({
data: systems,
success: true
});
});
I'm looking for a way to removes the subsystems that do not have sections.
After hours of searching I think there's no way to filter populate based on nested populate, so I tried with some ways like this:
if (systems.subsystems.length > 0) {
let test = [];
systems.subsystems.forEach((value, index) => {
if (value.sections.length !== 0) {
test[index] = value;
}
if (systems.subsystems.length === index + 1) {
return test;
}
})
}
But I'm not sure if this is the correct way.

You can use an aggregate query with $filter like this:
db.collection.aggregate([
{
"$project": {
"_id": 1,
"maxUserLevel": 1,
"subsystems": {
"$filter": {
"input": "$subsystems",
"as": "s",
"cond": {
"$ne": [
"$$s.sections",
[]
]
}
}
}
}
}
])
Example here
Also your query should contains a $match stage (like your find stage) and $lookup.

I'm not sure this is the best way, but it solved my problem:
const _ = require('lodash');
systems.forEach((value, index) => {
systems[index].subsystems = _.filter(value.subsystems,
item => !item.sections.length == 0
);
if (systems.length === index + 1) {
return systems;
}
});
It removes all subsystems that do not have sections.

Javascript Object array get last array

I have a json object array I have two functions. One to get the last message and the other to get. I need to keep the outer format the same but only return the one message.
I am getting the Json from the Telegram api and I have a Node Express script to return the reformatted Json
Here is the full Json:
{
"ok": true,
"result": [
{
"update_id": 650787950,
"channel_post": {
"message_id": 258,
"chat": {
"id": -1001497153100,
"title": "TestBot",
"type": "channel"
},
"date": 1592256395,
"text": "test messge"
}
},
{
"update_id": 650787951,
"channel_post": {
"message_id": 259,
"chat": {
"id": -1001497153100,
"title": "TestBot",
"type": "channel"
},
"date": 1592256604,
"text": "next"
}
}
]
}
I have a function to store the object after an api call to Telegram:
storeUpdates(data){
this.messageData = data;
}
For the function to get the last message:
getlastMessage() {
return
}
I am trying to return the Json:
{
"ok": true,
"result": [
{
"update_id": 650787951,
"channel_post": {
"message_id": 259,
"chat": {
"id": -1001497153100,
"title": "TestBot",
"type": "channel"
},
"date": 1592256604,
"text": "next"
}
}
]
}
And for the function to get a specific update_id
getNextMessage(update_id) {
return
}
Again I am trying to get this format of a single message matching the passed in update_id
{
"ok": true,
"result": [
{
"update_id": 650787951,
"channel_post": {
"message_id": 259,
"chat": {
"id": -1001497153100,
"title": "TestBot",
"type": "channel"
},
"date": 1592256604,
"text": "next"
}
}
]
}
I am a little confused with the layers of object and arrays mixed.

Does this work?
const messages = {
ok: true,
result: [{
update_id: 650787950,
channel_post: {
message_id: 258,
chat: {
id: -1001497153100,
title: 'TestBot',
type: 'channel',
},
date: 1592256395,
text: 'test messge',
},
},
{
update_id: 650787951,
channel_post: {
message_id: 259,
chat: {
id: -1001497153100,
title: 'TestBot',
type: 'channel',
},
date: 1592256604,
text: 'next',
},
},
],
};
const getLastMessage = (messages) => {
final = {
ok: true,
result: [],
};
final.result.push(messages.result[messages.result.length - 1]);
return final;
};
const getNextMessage = (update_id, messages) => {
final = {
ok: true
};
final.result = messages.result.filter((msg) => {
return msg.update_id === update_id;
});
return final;
};
console.log(getLastMessage(messages));
console.log(getNextMessage(650787950, messages));
You get the last message by returning the last element in the array, by getting the length of the array and -1
I used Array.prototype.filter() to find the correct object.

To get the last result you would need to go to results and return the last index:
function getlastMessage(resultObject) {
return {
ok: resultObject.ok
result: [resultObject.result[resultObject.result.length - 1]]
}
}
To get the message by update_id:
getNextMessage(update_id) {
return {
ok: resultObject.ok
result: [resultObject.result.find(message => message.update_id === update_id)]
}
}
Something along these lines

Using destructuring you can make your code a little bit more compact:
const someObject = JSON.parse(`{
"ok": true,
"result": [
{
"update_id": 650787950,
"channel_post": {
"message_id": 258,
"chat": {
"id": -1001497153100,
"title": "TestBot",
"type": "channel"
},
"date": 1592256395,
"text": "test messge"
}
},
{
"update_id": 650787951,
"channel_post": {
"message_id": 259,
"chat": {
"id": -1001497153100,
"title": "TestBot",
"type": "channel"
},
"date": 1592256604,
"text": "next"
}
}
]
}`)
const getNextMessage = (update_id) => {
return {
...someObject,
result: someObject.result.find(message => message.update_id === update_id)
}
}
const getLastMessage = () => {
const arrayLength = someObject.result.length;
return {
...someObject,
result: someObject.result[arrayLength - 1]
}
}
console.log(getNextMessage(650787950))
console.log(getLastMessage())
If you want to keep the result type as an array you can use filter instead of find and surround the last element of result array with square brackets, like this:
const getNextMessage = (update_id) => {
return {
...someObject,
result: someObject.result.filter(message => message.update_id === update_id)
}
}
const getLastMessage = () => {
const arrayLength = someObject.result.length;
return {
...someObject,
result: [someObject.result[arrayLength - 1]]
}
}

Parse array of objects recursively and filter object based on id

i have this array of objects : getCategory (variable)
[
{
"id": "20584",
"name": "Produits de coiffure",
"subCategory": [
{
"id": "20590",
"name": "Coloration cheveux",
"subCategory": [
{
"id": "20591",
"name": "Avec ammoniaque"
},
{
"id": "20595",
"name": "Sans ammoniaque"
},
{
"id": "20596",
"name": "Soin cheveux colorés"
},
{
"id": "20597",
"name": "Protection"
},
{
"id": "20598",
"name": "Nuancier de couleurs"
}
]
},
{
"id": "20593",
"name": "Soins cheveux",
"subCategory": [
{
"id": "20594",
"name": "Shampooing"
},
{
"id": "20599",
"name": "Après-shampooing"
},
{
"id": "20600",
"name": "Masques"
},
and i tried everything i could search in stackoverflow ..
lets say on this array i want to get recursively and object with the specified id .. like 20596 and it should return
{
"id": "20596",
"name": "Soin cheveux colorés"
}
The logic way i am doing is like this :
var getSubcategory = getCategory.filter(function f(obj){
if ('subCategory' in obj) {
return obj.id == '20596' || obj.subCategory.filter(f);
}
else {
return obj.id == '20596';
}
});
dont know what else to do .
Thanks
PS : I dont use it in browser so i cannot use any library . Just serverside with no other library . find dont work so i can only use filter

You need to return the found object.
function find(array, id) {
var result;
array.some(function (object) {
if (object.id === id) {
return result = object;
}
if (object.subCategory) {
return result = find(object.subCategory, id);
}
});
return result;
}
var data = [{ id: "20584", name: "Produits de coiffure", subCategory: [{ id: "20590", name: "Coloration cheveux", subCategory: [{ id: "20591", name: "Avec ammoniaque" }, { id: "20595", name: "Sans ammoniaque" }, { id: "20596", name: "Soin cheveux colorés" }, { id: "20597", name: "Protection" }, { id: "20598", name: "Nuancier de couleurs" }] }, { id: "20593", name: "Soins cheveux", subCategory: [{ id: "20594", name: "Shampooing" }, { id: "20599", name: "Après-shampooing" }, { id: "20600", name: "Masques" }] }] }];
console.log(find(data, '20596'));
console.log(find(data, ''));