在单个MongoDB集合/容器中存在合并多个文档类型

// Book document
{
  "_id": ObjectId("60c72b2f9b1d8b3f4c8b4567"),
  "type": "book",
  "title": "The Great Gatsby",
  "author": "F. Scott Fitzgerald",
  "published_year": 1925
}

// Movie document
{
  "_id": ObjectId("60c72b2f9b1d8b3f4c8b4568"),
  "type": "movie",
  "title": "Inception",
  "director": "Christopher Nolan",
  "release_year": 2010
}

db.items.insertMany([
  {
    "type": "book",
    "title": "The Great Gatsby",
    "author": "F. Scott Fitzgerald",
    "published_year": 1925
  },
  {
    "type": "movie",
    "title": "Inception",
    "director": "Christopher Nolan",
    "release_year": 2010
  }
]);

db.items.find({ "type": "book" });

db.items.find({ "type": "movie" });

db.items.updateOne(
  { "type": "book", "title": "The Great Gatsby" },
  { $set: { "published_year": 1926 } }
);

db.items.deleteOne({ "type": "movie", "title": "Inception" });

db.items.createIndex({ "type": 1 });

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const bookSchema = new Schema({
  type: { type: String, default: 'book' },
  title: String,
  author: String,
  published_year: Number
});

const movieSchema = new Schema({
  type: { type: String, default: 'movie' },
  title: String,
  director: String,
  release_year: Number
});

const Item = mongoose.model('Item', new Schema({}, { strict: false }));

const Book = Item.discriminator('Book', bookSchema);
const Movie = Item.discriminator('Movie', movieSchema);

const book = new Book({
  title: 'The Great Gatsby',
  author: 'F. Scott Fitzgerald',
  published_year: 1925
});

const movie = new Movie({
  title: 'Inception',
  director: 'Christopher Nolan',
  release_year: 2010
});

book.save();
movie.save();