Mongoose and MongoDB, how to create relation betwean two models with multiple references? - mongodb

Question

everyone.
So I have this "blog" app where users can create posts with images.
How my app works is that it loads different posts by userID.
So I have a relation bewtean user and post by the user and post _id, however I also want to save username into the post schema and created ralation that way. Is it possible to do such thing ?
This is my User schema
import mongoose from "mongoose";
import mongooseUniqueValidator from "mongoose-unique-validator";
const Schema = mongoose.Schema;
const validator = mongooseUniqueValidator;
const user_Schema = new Schema({
username: { type: String, required: true, unique: true },
email: { type: String, required: true, unique: true },
password: { type: String, required: true, minlength: 3 },
user_image: { type: String },
posts: [{ type: mongoose.Types.ObjectId, required: true, ref: 'Post' }], //relation bewtean post and user
},{ timestamps: true }
);
user_Schema.plugin(validator);
export const USER: mongoose.Model<any> = mongoose.model("User", user_Schema);
And this is my Post Schema:
import mongoose from "mongoose";
const Schema = mongoose.Schema;
const post_Schema = new Schema({
title: { type: String, required: true, },
description: { type: String, required: true, },
imageURL: { type: String },
creator_id: { type: mongoose.Types.ObjectId, required: true, ref: 'User' },
},
{ timestamps: true }
);
export const POST: mongoose.Model<any> = mongoose.model("Post", post_Schema);
However this is what I want the post to contain, I want the post to contain ID of the user who created it and the name of the user who created it.
However I do not know how to create it. So this is how I want my Post schema to look like, I want to be able to save both the user ID and username into the post.
const Schema = mongoose.Schema;
const post_Schema = new Schema({
title: { type: String, required: true, },
description: { type: String, required: true, },
imageURL: { type: String },
user: {
creator_id: { type: mongoose.Types.ObjectId, required: true, ref: 'User' }, //relation bewtean post and user
creator_name: { <soemthing here>, ref: 'User' }, //relation bewtean post and user
},
},
{ timestamps: true }
);
export const POST: mongoose.Model<any> = mongoose.model("Post", post_Schema);

Answer 1

If you want to retrieve the creator name using the ref is the correct approach, you just need to populate the Post documents when you are retrieving them with:
const posts = await Post.find({}).populate('creator').exec()
for (const post of posts) {
// Every post should contain the creator user properties
console.log(post.creator._id, post.creator.username)
}
Just make sure that your ref fields are of type mongoose.Schema.Types.ObjectId:
const post_Schema = new Schema(
{
title: { type: String, required: true },
description: { type: String, required: true },
imageURL: { type: String },
creator: { type: mongoose.Schema.Types.ObjectId, required: true, ref: 'User' },
},
{ timestamps: true }
);
export const POST: mongoose.Model<any> = mongoose.model('Post', post_Schema);