Using lowdb

This article is written for Fullyhacks 2024. It is a guide to using lowdb, a simple JSON database for small projects.

What is a database?

A database is a collection of data stored persistently. It allows for storage and later retrieval of data. Almost all applications require some form of database to store data.

For example:

• If you’re building Facebook, you would need a database to store user profiles and posts.
• If you’re building Discord, you would need a database to store user messages and channels.

What is lowdb?

lowdb is a very simple JSON-backed database. This means that the entire database is stored in a single JSON file. It is very easy to use and is perfect for small projects.

In reality, no one would ever use lowdb for real-world applications. It is not performant, it is not scalable, and it is not efficient. However, it is perfect for small projects such as Hackathons.

How to use lowdb

To use lowdb, you need to install it first. You can install it using npm:

npm i lowdb

Once you have installed lowdb, you can use it in your project. Here is an example of how to use lowdb in JavaScript:

const db = await JSONFilePreset("database.json", {
  // Populate our database with a default value:
  users: [],
  posts: [],
});

db.data.users.push({ name: "Alice" });
db.data.posts.push({ body: "Hello, world!", author: "Alice" });
await db.write();

// Find Alice's profile:
console.log(db.data.users.find(u => u.name == "Alice"))

// Find Alice's posts:
console.log(db.data.posts.filter(p => p.author == "Alice"))

If you’re a fan of TypeScript, you can give your database a schema:

export type User = {
  name: string;
}

export type Post = {
  body: string;
  author: string;
}

type Schema = {
  users: User[];
  posts: Post[];
}

const db = await JSONFilePreset<Schema>("database.json", {
  // Populate our database with a default value:
  users: [],
  posts: [],
});

That’s it! Go give lowdb a try and a star!