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

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);

CodePudding user response：

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);