Express js 09: Implementing Mongoose findById and findByIdAndDelete

In this tutorial, we will be discussing how to use Mongoose’s findById and findByIdAndDelete methods in an Express.js application. These methods are useful for retrieving and deleting documents from a MongoDB database.

Prerequisites:

1. Node.js installed on your machine.
2. MongoDB installed on your machine.
3. Basic knowledge of Express.js and Mongoose.

Step 1: Set up your Express.js application
To begin, create a new directory for your project and run npm init to create a package.json file. Then, install Express and Mongoose by running the following commands:

npm install express mongoose

Create a new file app.js and set up the basic Express server:

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

const app = express();

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

Step 2: Connect to MongoDB
Next, connect to your MongoDB database using Mongoose. Add the following code to your app.js file:

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

Make sure to replace mydatabase with the name of your database.

Step 3: Create a Mongoose schema and model
Before using the findById and findByIdAndDelete methods, we need to define a Mongoose schema and model for the documents in our database. Let’s create a simple schema for a Product document:

const productSchema = new mongoose.Schema({
  name: { type: String, required: true },
  price: { type: Number, required: true }
});

const Product = mongoose.model('Product', productSchema);

Step 4: Implement findById and findByIdAndDelete in your Express routes
Now that we have set up our database connection and defined a Mongoose model, let’s implement our findById and findByIdAndDelete routes in Express.

app.get('/products/:id', async (req, res) => {
  const id = req.params.id;

  try {
    const product = await Product.findById(id);

    if (!product) {
      return res.status(404).json({ message: 'Product not found' });
    }

    res.json(product);
  } catch (error) {
    res.status(500).json({ message: error.message });
  }
});

app.delete('/products/:id', async (req, res) => {
  const id = req.params.id;

  try {
    const product = await Product.findByIdAndDelete(id);

    if (!product) {
      return res.status(404).json({ message: 'Product not found' });
    }

    res.json({ message: 'Product deleted successfully' });
  } catch (error) {
    res.status(500).json({ message: error.message });
  }
});

Step 5: Test the routes
You can now test the findById and findByIdAndDelete routes by making HTTP requests to your Express server. You can use tools like Postman or curl to send GET and DELETE requests to the respective endpoints:

GET http://localhost:3000/products/:id
DELETE http://localhost:3000/products/:id

Make sure to replace :id with the actual ID of a document in your database.

That’s it! You have successfully implemented findById and findByIdAndDelete methods in an Express.js application using Mongoose. Experiment with different queries and error handling to further enhance your application.