How can i populate multiple paths in my DB? - node.js

Question

I want different values from the nested schema. How can I populate them so that every field is showing me its nested data and not the object ID?
I'm using MongoDB and node/express.
This is my postDB where the post schema is defined:
const mongoose = require('mongoose');
var postSchema = new mongoose.Schema({
title: {
type:String,
required:true
},
body: {
type:String,
required:true
},
comments:[{
type: mongoose.Schema.Types.ObjectId,
ref: "comment"
}],
category:{
type:String,
required:true
},
creator: {
type: mongoose.Schema.Types.ObjectId,
ref: "user"
}
},{timestamps : true}
)
module.exports = mongoose.model('postData', postSchema);
This is my commentDB which is referenced from the postDB:
const mongoose = require('mongoose');
// Using the Schema constructor, create a new CommentSchema object
// This is similar to a Sequelize model
var CommentSchema = new mongoose.Schema({
// `body` is of type String
creator: {
type: mongoose.Schema.Types.ObjectId,
ref: "user"
},
body: String
},{timestamps : true});
var Comment = mongoose.model("comment", CommentSchema);
module.exports = Comment;
This is how I'm trying to populate:
router.get('/READ', (req,res)=>{
posts.find({}, function (err, post) {
if (err) {
console.log(err);
}else{
res.json({post})
}
}
)
.populate([{path:'creator'}, {path:'comments'}])
})
However the results i get from this does not populate every object ID.
For example:
{
"comments": [
{
"_id": "5f8d91d8f8550044f0f755c8",
"creator": "5f84e5b1d893ac42dcc9cb78",
"body": "This looks cool",
"createdAt": "2020-10-19T13:17:12.323Z",
"updatedAt": "2020-10-19T13:17:12.323Z",
"__v": 0
},
{
"_id": "5f8d92e82ecfbe34b8f6375b",
"creater": "5f84e5b1d893ac42dcc9cb78",
"body": "hello",
"createdAt": "2020-10-19T13:21:44.463Z",
"updatedAt": "2020-10-19T13:21:44.463Z",
"__v": 0
},
],
"_id": "5f887cef6fd7d34548a592ea",
"title": "A DESCRIPTIVE PARAGRAPH EXAMPLE",
"body": "\"The room in which I found myself was very large and lofty. The windows were ",
"category": "Finance",
"creator": {
"joined": "2020-10-15T12:14:23.888Z",
"posts": [
"5f887cef6fd7d34548a592ea",
"5f887e0d6fd7d34548a592ec",
"5f887e266fd7d34548a592ed",
"5f887e586fd7d34548a592ee",
"5f89bfccc2bebd40b07b044a",
"5f89c36e906bbb27b84af897",
"5f89c7614199d52b141ff249",
"5f89c7ea4199d52b141ff24a",
"5f8c5ab175ef762ed89eddba",
"5f8c5be2d7fac046f0021d9f"
],
"_id": "5f88481d00ed460960da90f8",
"username": "kenwaysharma",
"email": "kenwaysharma#gmail.com",
"password": "$2b$10$p3qjmdSKWIF9qAagZoqbjuG34cjOgXTe5XYER0aowwviIS65COVlu",
"__v": 0
},
"__v": 0,
"updatedAt": "2020-10-20T05:42:56.320Z"
}
Here is the userDB:
username: {
type: String,
required: [true, "Username is required!"],
unique: true,
lowercase: true,
},
email:{
type: String,
required: [true, "Email is required!"],
unique: true,
lowercase: true,
validate: [isEmail, "Please enter a valid email!"]
},
password:{
type: String,
required: [true, "Password is required!"],
minlength: [6, "Enter atleast 6 characters!"],
},
comments:[{
type: mongoose.Schema.Types.ObjectId,
ref: "comment"
}],
posts:[{
type: mongoose.Schema.Types.ObjectId,
ref: "postData"
}],
},{timestamps : true});
GET users:
router.get('/USERS', (req,res)=>{
User.find({}, function (err, user) {
if (err) {
console.log(err);
}else{
res.send(user)
}
}
).populate('comments') .populate('posts')
})
How do I get the creator data inside of comments instead of just its object ID?
Update:
I also tried selecting the creator inside comments like
.populate('comments', 'creator')
but it still gives me the creator object ID in a string.
Update 2:
I have added the code for userDB to which the commentDB and postDB references.
Also added the GET users just to see how it works in postman.

Answer 1

Try chaining multiple populate methods and using the exec method to pass your callback.
posts.find({})
.populate({
path: 'comments',
populate: {
path: 'creator',
model: 'user'
}
})
.populate('creator')
.exec(function (err, post) {
if (err) {
console.log(err);
}else{
res.json({post})
}
});