text: const mongoose = require("mongoose");
  
  mongoose
    .connect("mongodb://localhost/playground")
    .then(() => console.log("Connected to MongoDB..."))
    .catch((err) => console.error("Could not connect to MongoDB...", err));
  
  const Author = mongoose.model(
    "Author",
    new mongoose.Schema({
      name: String,
      bio: String,
      website: String,
    })
  );
  
  const Course = mongoose.model(
    "Course",
    new mongoose.Schema({
      name: String,
      author: {
        type: mongoose.Schema.Types.ObjectId,
        ref: "Author",
      },
    })
  );
  
  async function createAuthor(name, bio, website) {
    const author = new Author({
      name,
      bio,
      website,
    });
  
    const result = await author.save();
    console.log(result);
  }
  
  async function createCourse(name, author) {
    const course = new Course({
      name,
      author,
    });
  
    const result = await course.save();
    console.log(result);
  }
  
  async function listCourses() {
    const courses = await Course.find()
      .populate("author", "name -_id")
      .select("name author");
    console.log(courses);
  }
  
  // createAuthor("Cristian", "My bio", "My Website");
  
  // createCourse("Node Course", "605ea9874891a671ac69f2fa");
  
  listCourses();
  