Mongoose Querying on Array of Object or Virtual for array of Object

Question

I have the following Mongoose schema as defined on this page

const AuthorSchema = new Schema({
    name: String
});



const BlogPostSchema = new Schema({
  title: String,
  author: { type: mongoose.Schema.Types.ObjectId, ref: 'Author' },
  comments: [{
    author: { type: mongoose.Schema.Types.ObjectId, ref: 'Author' },
    content: String
  }]
});

Now I want to create a virtual on AuthorSchema to get the BlogPosts which have comments of that author.

I tried creating a virtual function but with no success

Answer 1

Both virtual and methods can solve your problems:

Virtual:

// Model
AuthorSchema.virtual('blogPosts').get(function () {
  return this.model('BlogPost').find({
    comments: { $elemMatch: { author: this._id } },
  })
});

// Usage
const author = await Author.findById(id);
const blogPosts = await author.blogPosts;

Methods:

// Model
AuthorSchema.method.blogPosts= function (cb) {
  return this.model('BlogPost').find({
    comments: { $elemMatch: { author: this._id } },
  }, cb)
};

// Usage
const author = await Author.findById(id);
const blogPosts = await author.blogPosts();