Develop Reference

Mongoose populate returns an empty array | multiple levels of embedded documents

I am trying to populate my ChatRoom model with the User reference. However, it returns a ChatRoom object with only _ids where I expected usernames, as if I never applied populate on it.
Here is an extract of my ChatRoom model :
const ChatRoom = mongoose.model("ChatRoom", {
sender: {
type: mongoose.Schema.Types.ObjectId,
ref: "User",
},
roomname: { type: String, default: "new room" },
messages: [
{
messages: {
type: mongoose.Schema.Types.ObjectId,
ref: "Message",
},
meta: [
{
user: {
type: mongoose.Schema.Types.ObjectId,
ref: "User",
},
delivered: Boolean,
read: Boolean,
},
],
},
],
participants: [
{
user: { type: mongoose.Schema.Types.ObjectId, ref: "User" },
},
],
isPrivate: { type: Boolean, default: "false" },
});
My User model :
const User = mongoose.model("User", {
username: { required: true, unique: true, type: String },
avatar: Object,
token: String,
hash: String,
salt: String,
chatroom: {
type: mongoose.Schema.Types.ObjectId,
ref: "ChatRoom",
},
});
As this seems to be a recurrent issue, I tested several StackOverflow answers for my populate code :
Using populate('participants.user') and 'model: user' or just populate('participants.user'), same solution here:
const chatroom = await ChatRoom.findById(req.params.id)
.populate([
{
path: "participants.user",
model: "User",
},
])
.exec((err, user) => {
if (err) {
console.log("error", err);
} else {
console.log("Populated User " + user);
}
});
The console.log returns :
Populated User { _id: new ObjectId("62262b342e28298eb438d9eb"),
sender: new ObjectId("6225d86c9340237fe2a3f067"), roomname:
'Hosmeade', participants: [ { _id: new
ObjectId("6225d86c9340237fe2a3f067") } ], isPrivate: false,
messages: [], __v: 0 }
As if no populate method was ever applied. On the client side, I get an empty string.
Checking my documents aren't empty, this link mentions that Mongoose get problems with detecting referring model across multiple files but the solution doesn't work for me :
_id:6225d86c9340237fe2a3f067 username:"Berlioz" token:"rTCLAiU7jq3Smi3B"
hash:"wvJdqq25jYSaJjfiHAV4YRn/Yub+s1KHXzGrkDpaPus="
salt:"hZdiqIQQXGM1ryYK" avatar:Object
__v:0
If I remove the .exec(...) part, I get the info on the client side, but participants is still filled with only id :
chatroom response : Object { _id: "62262bb14e66d86fb8a041e8",
sender: "6225d86c9340237fe2a3f067", roomname: "Very secret room",
participants: (1) […], isPrivate: false, messages: [], __v: 0 }
I also tried with select: 'username' and get the same result as above :
const chatroom = await ChatRoom.findById(req.params.id).populate({
path: "participants.user",
select: "username",
});
Populating it "as an array"
Changing type of participants.user in my ChatRoom model into an Object (nothing changes)
If needed hereafter are my repos:
Client side and Backend
I run out of ideas on how to debbug my code. Any help would be great !

How to insert ref objectId in nodejs?

Main Model
{
name: {
type: String,
trim: true,
required: true
},
carModels: [{
type: ObjectId,
ref: 'CarModel'
}]
}
Second Model
{
name: {
type: String,
trim: true,
required: true
},
carModels: [
{
type: ObjectId,
ref: 'CarModel'
}
]
},
Third Model
{
name: {
type: String,
trim: true,
required: true
}
},
Here i am trying to insert the data like this
{
"name": "test",
"phoneNumber": "0123456789",
"email": "m#m.com",
"carMakes": [{
"name": "BMW",
"carModels": [{
"_id": "some id"
}]
}]
}
and it giving me error like
carMakes.0: Cast to [ObjectId] failed for value
here is the create function
export const create = async data => {
const result = await Booking(data).save();
return result;
};
Can anyone tell what I am missing here ..i am learning nodejs

i think the problem is with the _id that you're passing to carModel and since you set the type to ObjectId it has to be in a valid format "either 12 byte binary string, or a 24 hex byte string" and "some id" is not the valid one if you're sending that.
you can check if your id is valid with isValidObjectId() function.
or you can easily generate an ObjectId:
var mongoose = require('mongoose');
var id = new mongoose.Types.ObjectId();

use mongooseModel.find() on schema that has a Schema.Types.Mixed property

I have trouble using postModel.find() query in a schema that defined as Schema.Types.Mixed.
this is a sample of my schema
const PostSchema = new mongoose.Schema({
//.....
address: {
type: String,
required: true,
},
postDetails: {
type: Schema.Types.Mixed,
required: true,
},
author: {
type: Schema.Types.ObjectId,
ref: 'User',
},
//.....
});
this is a sample document stored in db
{
//.....
"state": "Lakes State",
"address": "some address",
"postDetails": {
"type": "Cages",
"condition": "Used"
},
//......
}
it is giving me an empty array if I use this
const queryObject = {
postDetails: {
type: 'Cages',
},
};
return this.postModel.find(queryObject);
but it gives the desired results if I include all the properties like this
const queryObject = {
postDetails: {
type: 'Cages',
condition: 'Used',
},
};
return this.postModel.find(queryObject);
How do i get all matching posts that have postDetails.type = 'Cages' ? without knowing all available properties inside postDetails
there are some similar questions about this here. but most of them are using arrays instead of an object

You can use dot notation for querying embedded documents
postModel.find({
"postDetails.type": "Cages"
});

Push To Mongoose Subdocuments

Hello I am creating a series of groupings describing the roles certain users are taking within the context of helping a client. The object in the Prospect model is called caseworkers. In caseworkers is a series of arrays for the different types of roles done. The equation is to allow the user to push his info as a subdocument called CaseWorker. Basically creating an object with 6 arrays that users can push to. Ive tried a few things and settled on Subdocuments. Any help would be awesome.
Here is my code:
const mongoose = require("mongoose");
const CaseWorker = require("./CaseWorker");
const ProspectSchema = mongoose.Schema({
caseWorkers: {
originators: [CaseWorker.schema],
loanProcessors: [CaseWorker.schema],
documentProcessors: [CaseWorker.schema],
upsells: [CaseWorker.schema],
primaryReso: [CaseWorker.schema],
taxPreparers: [CaseWorker.schema],
secondaryReso: [CaseWorker.schema],
}
module.exports = mongoose.model("prospect", ProspectSchema);
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
const CaseWorkerSchema = new Schema({
name: {
type: String,
required: true,
},
email: {
type: String,
required: true,
unique: true,
},
role: { type: String },
resoCred1: { type: String },
resoCred2: { type: String },
reminders: [
{
_id: { type: mongoose.Schema.Types.ObjectId, ref: "User" },
userReminded: { type: mongoose.Schema.Types.ObjectId },
reminderDate: { type: Date },
reminderDueDate: { type: Date },
status: { type: String },
daysTilDue: { type: Number },
id: { type: String },
text: { type: String },
clientId: { type: mongoose.Schema.Types.ObjectId, ref: "Prospect" },
},
],
});
module.exports = mongoose.model("caseWorker", CaseWorkerSchema);
router.put("/:_id/caseWorkers/loanProcessors", auth, async (req, res) => {
const prospect = await Prospect.findByIdAndUpdate(req.params._id, {
"$push": {
"loanProcessors": {
"caseWorker": {
"name": req.body.name,
"email": req.body.email,
"role": req.body.role,
"resoCred1": req.body.resoCred1,
"resoCred2": req.body.resoCred2,
},
},
},
});
res.json(prospect);
console.log(prospect);
});

In your approach when updating the document you put caseWorker under loanProcessors but it's declared in the schema the other way around.
To update a nested object you have to use the dot notation to reference the field.
Don't forget to put the object key that represent the field as a string like this "caseWorkers.loanProcessors", because caseWorkers.loanProcessors is an invalid object key in javascript
"$push": {
"caseWorkers.loanProcessors": {
"name": req.body.name,
"email": req.body.email,
"role": req.body.role,
"resoCred1": req.body.resoCred1,
"resoCred2": req.body.resoCred2,
},
},

Can't get populate() to fill out array in Mongoose

Let me begin by saying I know that this seems to be a frequently asked question and I've spent a couple of days trying to figure it out but no answer seems to work so I'm trying on here.
I have two models, User and Chapter: a Chapter can have have many members (Users). When I do router.get('/chapters') I want to see an array of all the Users associated with a Chapter as a property along with the other Chapter properties, like so:
[
{
"leads": [],
"members": [
{"_id":"someString1","firstName":"...", "lastName":"..."},
{"_id":"someString2","firstName":"...", "lastName":"..."},
],
"date": "2018-12-12T15:24:45.877Z",
"_id": "5c11283d7d13687e60c186b3",
"country": "5c11283d7d13687e60c185d6",
"city": "Buckridgestad",
"twitterURL": "qui",
"bannerPic": "http://lorempixel.com/640/480/people",
"__v": 0
}
]
But what I'm getting is this:
[
{
"leads": [],
"members": [],
"date": "2018-12-12T15:24:45.877Z",
"_id": "5c11283d7d13687e60c186b3",
"country": "5c11283d7d13687e60c185d6",
"city": "Buckridgestad",
"twitterURL": "qui",
"bannerPic": "http://lorempixel.com/640/480/people",
"__v": 0
}
]
These are my Schemas:
Chapter
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
// Create Schema
const ChapterSchema = new Schema({
country: {
type: Schema.Types.ObjectId,
ref: "countries"
},
city: {
type: String,
required: true
},
leads: [
{
type: Schema.Types.ObjectId,
ref: "users"
}
],
members: [
{
type: Schema.Types.ObjectId,
ref: "users"
}
],
twitterURL: {
type: String,
required: true
},
bannerPic: {
type: String,
required: true
},
date: {
type: Date,
default: Date.now()
}
});
module.exports = Chapter = mongoose.model("chapters", ChapterSchema);
User
const mongoose = require("mongoose");
const Schema = mongoose.Schema;
// Create Schema
const UserSchema = new Schema({
username: {
type: String,
required: true
},
firstName: {
type: String,
required: true
},
lastName: {
type: String,
required: true
},
organisation: {
type: String,
required: true
},
chapter: {
type: Schema.Types.ObjectId,
ref: "chapters"
},
email: {
type: String,
required: true
},
admin: {
type: Boolean,
default: false
},
lead: {
type: Boolean,
default: false
},
password: {
type: String,
required: true
},
date: {
type: Date,
default: Date.now()
}
});
module.exports = User = mongoose.model("users", UserSchema);
Like I said, when I call the endpoint, I want it to return me all the Chapters with all the Users as a populated property.
I've tried a lot of variations of .populate() but to know luck. The closest I got was going through the early levels of callback hell which I know isn't necessary with today's tech, but nothing is working!
My routes/api/chapters.js
// #route GET api/chapters
// #desc Get all Chapters
// #access Public
router.get("/", (req, res) => {
Chapter.find()
.populate("members")
.then(chapters => {
return res.json(chapters);
})
.catch(err =>
res.status(404).json({ nochaptersfound: "No Chapters found" })
);
});
I can get it to work the other way around:
My routes/api/users.js
// #route GET api/users
// #desc Return all users
// #access Public
router.get("/", (req, res) => {
User.find()
.populate("chapter")
.exec()
.then(users => res.status(200).json(users))
.catch(err => console.log(err));
Returns a user with the populated Chapter, but I can't populate the chapter.members array
Any help would be greatly appreciated!
Thanks!!

From your comment, I believe you are not actually storing users in your chapters. What you are doing is this:
User.create({..., chapter: id})...
And assuming chapter now has a user. Its not the way it works with mongoose, so if you want to actually save in both place, you will need to do it yourself. You are thinking about this as if it were a relational database
You will need to do something like:
const user = await User.create({..., chapter: id})
const chapter = await Chapter.findOne({ _id: id })
chapter.members.push(user)
chapter.save()
If your populate wasn't working, you'd not get an empty array, you'd get an array with ids. Your current populate query is fine, you just don't have any data to populate
With promises, it would look like this:
var userPromise = User.create({..., chapter: id}).exec()
var chapterPromise = Chapter.findOne({ _id: id }).exec()
Promise.all([userPromise, chapterPromise]).then((user, chapter) => {
chapter.members.push(user)
return chapter.save()
}).then(chapter => {
// send response
})
If you need 10 chapters with 10 to 50 users, I'd create 50 users, then push all of them into the chapters and save the chapter.