MongoDB with Node.js: Building a CRUD API

const express = require('express');
const mongoose = require('mongoose');

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

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

const bookSchema = new mongoose.Schema({
  title: String,
  author: String,
  pages: Number
});

const Book = mongoose.model('Book', bookSchema);

// Create
app.post('/books', async (req, res) => {
  try {
    const book = new Book(req.body);
    await book.save();
    res.status(201).send(book);
  } catch (err) {
    res.status(400).send(err);
  }
});

// Read all
app.get('/books', async (req, res) => {
  const books = await Book.find();
  res.send(books);
});

// Read one
app.get('/books/:id', async (req, res) => {
  try {
    const book = await Book.findById(req.params.id);
    if (!book) return res.status(404).send('Book not found');
    res.send(book);
  } catch (err) {
    res.status(400).send(err);
  }
});

// Update
app.put('/books/:id', async (req, res) => {
  try {
    const book = await Book.findByIdAndUpdate(req.params.id, req.body, { new: true, runValidators: true });
    if (!book) return res.status(404).send('Book not found');
    res.send(book);
  } catch (err) {
    res.status(400).send(err);
  }
});

// Delete
app.delete('/books/:id', async (req, res) => {
  try {
    const book = await Book.findByIdAndDelete(req.params.id);
    if (!book) return res.status(404).send('Book not found');
    res.send({ message: 'Book deleted' });
  } catch (err) {
    res.status(400).send(err);
  }
});

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