**Course Title:** Mastering Express.js: Building Scalable Web Applications and APIs **Section Title:** Working with Databases: MongoDB and Mongoose **Topic:** Create a RESTful API using Express.js and MongoDB with Mongoose for managing a resource (e.g., books, users).(Lab topic) **Overview:** In this lab topic, we will build a RESTful API using Express.js and MongoDB with Mongoose to manage a resource, such as books or users. By the end of this topic, you will gain hands-on experience in creating a scalable and efficient API that can perform CRUD (Create, Read, Update, Delete) operations. **Prerequisites:** Before starting this lab topic, make sure you have completed the following topics: * Introduction to Node.js and Express.js * Routing and Middleware * Working with Databases: MongoDB and Mongoose **Step 1: Define the Resource Model** In this step, we will define the resource model using Mongoose. For this example, let's create a Book model. ```javascript // models/Book.js const mongoose = require('mongoose'); const bookSchema = new mongoose.Schema({ title: String, author: String, publicationDate: Date, isbn: String }); const Book = mongoose.model('Book', bookSchema); module.exports = Book; ``` **Step 2: Create API Endpoints** In this step, we will create API endpoints for CRUD operations using Express.js. ```javascript // routes/books.js const express = require('express'); const router = express.Router(); const Book = require('../models/Book'); // Get all books router.get('/', async (req, res) => { try { const books = await Book.find(); res.json(books); } catch (err) { res.status(500).json({ message: err.message }); } }); // Get a book by ID router.get('/:id', async (req, res) => { try { const book = await Book.findById(req.params.id); if (!book) { res.status(404).json({ message: 'Book not found' }); } else { res.json(book); } } catch (err) { res.status(500).json({ message: err.message }); } }); // Create a new book router.post('/', async (req, res) => { try { const newBook = new Book(req.body); await newBook.save(); res.status(201).json(newBook); } catch (err) { res.status(400).json({ message: err.message }); } }); // Update a book router.put('/:id', async (req, res) => { try { const updatedBook = await Book.findByIdAndUpdate(req.params.id, req.body, { new: true }); if (!updatedBook) { res.status(404).json({ message: 'Book not found' }); } else { res.json(updatedBook); } } catch (err) { res.status(500).json({ message: err.message }); } }); // Delete a book router.delete('/:id', async (req, res) => { try { await Book.findByIdAndRemove(req.params.id); res.status(204).json({ message: 'Book deleted successfully' }); } catch (err) { res.status(500).json({ message: err.message }); } }); module.exports = router; ``` **Step 3: Mount API Endpoints** In this step, we will mount the API endpoints to the main application. ```javascript // app.js const express = require('express'); const app = express(); const booksRouter = require('./routes/books'); app.use('/api/books', booksRouter); app.listen(3000, () => { console.log('Server started on port 3000'); }); ``` **Testing the API** You can use tools like Postman or cURL to test the API endpoints. **Conclusion:** In this lab topic, we have created a RESTful API using Express.js and MongoDB with Mongoose to manage a resource, such as books or users. You can use this API as a starting point to build more complex APIs for your applications. **What to do next:** Try to extend the API by adding more endpoints, or try to use a different resource model. **Additional Resources:** * [Express.js API documentation](https://expressjs.com/en/api.html) * [Mongoose API documentation](https://mongoosejs.com/docs/api.html) * [MongoDB documentation](https://docs.mongodb.com/) **Leave a comment or ask for help:** If you have any questions or need help with this topic, please leave a comment below.