Schema Design

schema.js

var mongoose = require('mongoose')
var Schema = mongoose.Schema

/*
Creates a Schema
*/
var BookSchema = new Schema({
  title: String,
  published: {
    type: Date, // sets the type
    required: true, // sets a required value
    default: Date.now, // sets a default value
    unique: true // makes sure that this is unique entry
  },
  keywords: Array,
  author: {
    type: Schema.ObjectId, // references another object
    ref: User // references the User model and add it to this field
  },
  detail: {
    modelNumber: Number,
    hardcover: Boolean,
    reviews: Number,
    rank: Number
  }
})

// Get the sub object from ==> data.detail.modelNumber