Express.js with MongoDB

Integrating MongoDB with Express.js enables developers to build dynamic, data-driven web applications. MongoDB serves as a NoSQL database, and its flexibility complements the lightweight nature of Express.js.

 

Key Features of Express.js with MongoDB

• Scalable Database Integration: MongoDB's schema-less design allows for flexible data storage.
• RESTful APIs: Seamless creation of APIs to interact with the database.
• Asynchronous Operations: Leverage asynchronous operations for efficient data processing.
• Full-Stack Capabilities: Combine with front-end frameworks for end-to-end solutions.

 

Setting Up MongoDB with Express.js

Install Required Packages
Install mongodb or mongoose for database interactions.

Example:

npm install mongoose

Connect to MongoDB
Establish a connection using Mongoose.

Example:

const mongoose = require('mongoose');

mongoose.connect('mongodb://localhost:27017/mydatabase', { useNewUrlParser: true, useUnifiedTopology: true })
    .then(() => console.log('Connected to MongoDB'))
    .catch(err => console.error('Connection failed', err));

Define a Schema and Model
Create a schema for your data and define a model.

Example:

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

const User = mongoose.model('User', userSchema);

Create API Endpoints
Use Express.js routes to interact with the database.

Insert Data:

app.post('/add-user', async (req, res) => {
    const user = new User(req.body);
    try {
        await user.save();
        res.send('User added successfully');
    } catch (err) {
        res.status(400).send(err.message);
    }
});

Fetch Data:

app.get('/users', async (req, res) => {
    try {
        const users = await User.find();
        res.json(users);
    } catch (err) {
        res.status(500).send(err.message);
    }
});

Update Data:

app.put('/update-user/:id', async (req, res) => {
    try {
        const user = await User.findByIdAndUpdate(req.params.id, req.body, { new: true });
        res.json(user);
    } catch (err) {
        res.status(400).send(err.message);
    }
});

Delete Data:

app.delete('/delete-user/:id', async (req, res) => {
    try {
        await User.findByIdAndDelete(req.params.id);
        res.send('User deleted successfully');
    } catch (err) {
        res.status(500).send(err.message);
    }
});

 

Complete Example

const express = require('express');
const mongoose = require('mongoose');
const bodyParser = require('body-parser');

const app = express();
app.use(bodyParser.json());

// MongoDB connection
mongoose.connect('mongodb://localhost:27017/mydatabase', { useNewUrlParser: true, useUnifiedTopology: true });

// Schema and model
const userSchema = new mongoose.Schema({
    name: String,
    email: String,
    age: Number
});
const User = mongoose.model('User', userSchema);

// Routes
app.post('/add-user', async (req, res) => {
    const user = new User(req.body);
    try {
        await user.save();
        res.send('User added successfully');
    } catch (err) {
        res.status(400).send(err.message);
    }
});

app.get('/users', async (req, res) => {
    try {
        const users = await User.find();
        res.json(users);
    } catch (err) {
        res.status(500).send(err.message);
    }
});

// Server
app.listen(3000, () => {
    console.log('Server running on port 3000');
});

 

Summary

Express.js and MongoDB work seamlessly to handle database-driven applications. By using Mongoose or MongoDB's native driver, developers can efficiently manage CRUD operations, enabling robust back-end development.