Welcome back to another episode of Continuous Improvement, the podcast where we explore the world of software development and find ways to level up our coding skills. I’m your host, Victor. In today’s episode, we’re going to dive into connecting a Koa.js server to a MongoDB database. If you’re ready to learn, let’s get started!

Before we begin, make sure you have Koa.js and MongoDB installed. Once that’s done, let’s jump right into the steps.

Step one, connect to the database before initializing the Koa app. To do this, you’ll need to create a database.js file. Inside that file, import Mongoose, an Object Data Modeling (ODM) library, and your connection string from the configuration file. Remember to install Mongoose by running npm install --save mongoose.

const mongoose = require('mongoose');
import { connectionString } from './conf/app-config';

const initDB = () => {
  mongoose.connect(connectionString);

  mongoose.connection.once('open', () => {
    console.log('Connected to the database');
  });

  mongoose.connection.on('error', console.error);
};

module.exports = initDB;

Step two, create a schema in Koa. For example, let’s create a user schema inside the /models/users.js file.

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

const UserSchema = new Schema({
  username: String,
  email: String,
  picture: String
});

module.exports = mongoose.model('User', UserSchema);

Step three, create a service to query the data. In this example, we’ll create a /service/user.service.js file.

import User from '../models/users';

export const getUserFromDb = async (username) => {
  const data = await User.findOne({ username });
  return data;
};

export const createUserInDb = async (user) => {
  const newUser = new User(user);
  await newUser.save();
  return user;
};

And finally, step four, call the service in the Koa controller. For instance, let’s say we have a /controller/user.controller.js file.

import { getUserFromDb, createUserInDb } from '../service/user.service';

static async getUser(ctx) {
  const user = await getUserFromDb(ctx.query.username);
  ctx.body = user;
}

static async registerUser(ctx) {
  const user = await createUserInDb(ctx.request.body);
  ctx.body = user;
}

And there you have it! By following these steps, you should be able to connect your Koa.js server to a MongoDB database. If you have any questions or need further assistance, feel free to reach out.

That’s it for today’s episode of Continuous Improvement. I hope you found this information helpful in your journey as a developer. Don’t forget to subscribe to our podcast for more valuable insights and tips. Until next time, happy coding!