16.8. Creating a CRUD with NodeJS and MongoDB: Implementation of functions to create, read, update and delete data

For software developers, the ability to create, read, update, and delete data (CRUD) is an essential skill. In the context of our e-book course on how to create APIs in NodeJS, we will now focus on how to implement these operations using NodeJS and MongoDB.

Configuring the Environment

Before we get started, it's important to make sure you have the right development environment. You will need NodeJS and MongoDB installed on your system. In addition, we will use Express, a framework for NodeJS, and Mongoose, an ORM (Object Relational Mapping) for MongoDB.

Creating the Data Model

First, we need to define our data model. Let's assume we are creating an API for a blog application. So our data model could be a 'Post', with properties like 'title', 'content' and 'author'. Using Mongoose, we can define this model like this:

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const PostSchema = new Schema({
    title: String,
    content: String,
    author: String
});

module.exports = mongoose.model('Post', PostSchema);

Implementing CRUD Operations

Create

Let's start with the 'Create' operation. We will use the POST route for this. Here is an example of how this can be done:

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

router.post('/', async (req, res) => {
    const post = new Post({
        title: req.body.title,
        content: req.body.content,
        author: req.body.author
    });

    try {
        const savedPost = await post.save();
        res.json(savedPost);
    } catch (err) {
        res.json({ message: err });
    }
});

Read (Read)

Next, let's implement the 'Read' operation. We will use the GET route for this. Here is an example of how to read all posts and a specific post:

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// Get All Posts
router.get('/', async (req, res) => {
    try {
        const posts = await Post.find();
        res.json(posts);
    } catch (err) {
        res.json({ message: err });
    }
});

// Get Specific Post
router.get('/:postId', async (req, res) => {
    try {
        const post = await Post.findById(req.params.postId);
        res.json(post);
    } catch (err) {
        res.json({ message: err });
    }
});

Update

Now, let's implement the 'Update' operation. We will use the PATCH route for this. Here is an example of how to update a specific post:

router.patch('/:postId', async (req, res) => {
    try {
        const updatedPost = await Post.updateOne(
            { _id: req.params.postId },
            { $set: { title: req.body.title, content: req.body.content, author: req.body.author } }
        );
        res.json(updatedPost);
    } catch (err) {
        res.json({ message: err });
    }
});

Delete (Delete)

Finally, let's implement the 'Delete' operation. We will use the DELETE route for this. Here is an example of how to delete a specific post:

router.delete('/:postId', async (req, res) => {
    try {
        const removedPost = await Post.remove({ _id: req.params.postId });
        res.json(removedPost);
    } catch (err) {
        res.json({ message: err });
    }
});

Conclusion

With that, we complete the implementation of CRUD operations using NodeJS and MongoDB. The beauty of NodeJS is its simplicity and efficiency, and with the help of packages like Express and Mongoose, we can create powerful and scalable APIs. Remember, practice makes perfect, so keep practicing and experimenting.