Creating Custom APIs with MongoDB

Introduction

Custom APIs allow you to build specific functionalities and endpoints tailored to your application's needs. This tutorial will guide you through the steps to create a custom API using MongoDB, Node.js, and Express.js.

Setting Up

To get started, you need to set up a Node.js project and install the necessary dependencies:

Setting Up the Project

mkdir custom-api
cd custom-api
npm init -y
npm install express mongoose body-parser

Connecting to MongoDB

Create a db.js file to handle the connection to MongoDB:

db.js

const mongoose = require('mongoose');

const connectDB = async () => {
    await mongoose.connect('mongodb://localhost:27017/customapi', {
        useNewUrlParser: true,
        useUnifiedTopology: true,
    });
    console.log('MongoDB connected');
};

module.exports = connectDB;

Creating the User Model

Create a models/User.js file to define the MongoDB schema and model:

User.js

const mongoose = require('mongoose');

const userSchema = new mongoose.Schema({
    name: String,
    email: String,
});

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

Creating Express Routes

Create a routes/user.js file to define the API endpoints for user operations:

user.js

const express = require('express');
const router = express.Router();
const User = require('../models/User');

// Create a new user
router.post('/', async (req, res) => {
    const user = new User(req.body);
    await user.save();
    res.status(201).send(user);
});

// Get all users
router.get('/', async (req, res) => {
    const users = await User.find();
    res.status(200).send(users);
});

// Get a user by ID
router.get('/:id', async (req, res) => {
    const user = await User.findById(req.params.id);
    if (!user) return res.status(404).send('User not found');
    res.status(200).send(user);
});

// Update a user by ID
router.put('/:id', async (req, res) => {
    const user = await User.findByIdAndUpdate(req.params.id, req.body, { new: true, runValidators: true });
    if (!user) return res.status(404).send('User not found');
    res.status(200).send(user);
});

// Delete a user by ID
router.delete('/:id', async (req, res) => {
    const user = await User.findByIdAndDelete(req.params.id);
    if (!user) return res.status(404).send('User not found');
    res.status(200).send('User deleted');
});

module.exports = router;

Setting Up Express Server

Create an index.js file to set up the Express server and connect everything together:

index.js

const express = require('express');
const bodyParser = require('body-parser');
const connectDB = require('./db');
const userRoutes = require('./routes/user');

const app = express();
connectDB();

app.use(bodyParser.json());
app.use('/api/users', userRoutes);

const port = process.env.PORT || 3000;
app.listen(port, () => {
    console.log(`Server running on port ${port}`);
});

Running the Server

Start the server by running the following command:

Starting the Server

node index.js

You should see the message "Server running on port 3000" indicating that the Express server is running.

Testing the API

Use tools like Postman or curl to test the API endpoints. Here are some example requests:

Example: Creating a User

curl -X POST http://localhost:3000/api/users -H "Content-Type: application/json" -d '{"name":"John Doe","email":"john.doe@example.com"}'

Example: Getting All Users

curl http://localhost:3000/api/users

Conclusion

In this tutorial, you have learned how to create a custom API with MongoDB using Node.js and Express.js. This setup allows you to build flexible and powerful APIs for interacting with your MongoDB data.