lab-music-streaming-service 🎵

Description

In this lab, we're going to build a small-scale music streaming service database using MongoDB and Mongoose. We will create collections that represent artists, albums, songs, and playlists, and establish relationships between them.

Goal

By the end of this lab, you'll have a working MongoDB database that models a music streaming service, where artists release albums, albums contain songs, and users can create playlists of their favorite songs.

🏗️ Structure

We will create four collections:

1. Artists: Stores information about the artists.
2. Albums: Stores details about albums and references the artist.
3. Songs: Stores individual songs and references the album they belong to.
4. Playlists: Stores user-created playlists that can contain multiple songs from different albums.

🐣 Initial Steps

• Create a new file called seed.js.
• Initialize npm: npm init -y.
• Install the necessary packages: npm install mongoose dotenv.

🤫 Keep your secrets safe!

• Create a .env file.
• Create a .gitignore file and add the folders and files you don't want to push to your repository:

node_modules
package-lock.json
.env

• Add your MongoDB connection string in the .env file:

MONGODB_URL=mongodb://connection-string-to-your-mongoDB-with-user-and-password/your-database-name

👩‍💻 Let's Start Coding

1. Connect to the Database

First, connect to your MongoDB database using Mongoose:

Reveal the code 🙈

const mongoose = require("mongoose");
require("dotenv").config();

mongoose
  .connect(process.env.MONGODB_URL)
  .then((res) => {
    console.log("Connected to the database:", res.connections[0].name);
  })
  .catch((error) => {
    console.log("Error connecting to the database", error);
  });

2. Create Models

a. Artist Model

Create a model for the artists with a name and genre:

Reveal the code 🙈

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

const artistSchema = new Schema({
  name: String,
  genre: String,
});

const Artist = mongoose.model("Artist", artistSchema);

module.exports = Artist;

b. Album Model

Create a model for the albums with a title, release year, and a reference to the artist (by ObjectId):

Reveal the code 🙈

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

const albumSchema = new Schema({
  title: String,
  releaseYear: Number,
  artist: { type: Schema.Types.ObjectId, ref: "Artist" },
});

const Album = mongoose.model("Album", albumSchema);

module.exports = Album;

c. Song Model

Create a model for the songs with a title, duration, and a reference to the album (by ObjectId):

Reveal the code 🙈

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

const songSchema = new Schema({
  title: String,
  duration: Number,
  album: { type: Schema.Types.ObjectId, ref: "Album" },
});

const Song = mongoose.model("Song", songSchema);

module.exports = Song;

d. Playlist Model

Create a model for user playlists with a name and an array of song references (by ObjectId):

Reveal the code 🙈

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

const playlistSchema = new Schema({
  name: String,
  songs: [{ type: Schema.Types.ObjectId, ref: "Song" }],
});

const Playlist = mongoose.model("Playlist", playlistSchema);

module.exports = Playlist;

3. 🌱 Seed the Database

Now that the models are in place, let's seed the database with some initial data:

• Create an array of artists, albums, songs, and playlists.
• Use the insertMany method to add the data to your collections.
• You can use chatGPT to generate a JSON file with sample data for artists, albums, songs, and playlists.

Something like this:

{
  "artists": [
    {
      "name": "Artist 1",
      "genre": "Pop"
    },
    {
      "name": "Artist 2",
      "genre": "Rock"
    }
  ],
  "albums": [
    {
      "title": "Album 1",
      "releaseYear": 2021,
      "artist": "artist_id"
    },
    {
      "title": "Album 2",
      "releaseYear": 2020,
      "artist": "artist_id"
    }
  ],
  "songs": [
    {
      "title": "Song 1",
      "duration": 180,
      "album": "album_id"
    },
    {
      "title": "Song 2",
      "duration": 240,
      "album": "album_id"
    }
  ],
  "playlists": [
    {
      "name": "My Playlist",
      "songs": ["song_id", "song_id"]
    }
  ]
}

Try to make GPT create the proper objectIDs for the artist, album, and song references so they match.

Take your time, this is the most challenging part of the lab. 🧠

You may need to use the Promise.all method to wait for all the data to be inserted before closing the connection.

Hint:

    Promise.all([
      Artist.insertMany(data.artists),
      Album.insertMany(data.albums),
      Song.insertMany(data.songs),
      Playlist.insertMany(data.playlists),
    ]);

Reveal the code 🙈

const Artist = require("./models/Artist.model");
const Album = require("./models/Album.model");
const Song = require("./models/Song.model");
const Playlist = require("./models/Playlist.model");
// import the data
const data = require("./data.json");
mongoose
  .connect(process.env.MONGODB_URL)
  .then((res) => {
    console.log("Connected to the database:", res.connections[0].name);
  })
  .then(() => {
    return Promise.all([
      Artist.insertMany(data.artists),
      Album.insertMany(data.albums),
      Song.insertMany(data.songs),
      Playlist.insertMany(data.playlists),
    ]);
  })
  .catch((error) => {
    console.log("Error connecting to the database", error);
  });

Happy coding! 🎧