Project Setup

A project to demostrate rest-api crud operation in node-express application. Node and express allows for easy api building and super easy to create application.

create package.json

npm init -y

install express

npm install --save express

in index.js file

import express from 'express';  // both are same (works with node 14.5 and above..)
const express = require('express'); // old version

To enable the first line of code for above we have to make changes in package.json as follows

"type" : "module",

run server

npm start

install nodemon package to refresh the server on each save

npm install --save-dev nodemon

In package.json add under scripts. This is done to start application using nodemon.

"start": "nodemon index.js";

For modularity we create another folder where we would store all our routes create a folder routes/users.js which has the following basic template.

import express from 'express';

// Use the express.Router class to create modular, mountable route handlers
const router = express.Router();

// routes here
// eg: router.get(...)

// export the app `router` so that it can be imported in index.js
export default router;

Now import the exported router app to index.js as follows

import router from './routes/users.js';

app.use("/people", router);

now

router.post('/', (req, res) => {
    // when making post request, we have access to req.body
    user_list.push(req.body);  // user_list is list of dictoriay contianing all users
})

Next step: Setting up mongo db database

npm install mongoose

import mongoose from 'mongoose';

const CONNECTION_URL = "mongodb+srv://<username>:<password>@cluster0.frghl.mongodb.net/<data_basename>?retryWrites=true&w=majority";
mongoose.connect(CONNECTION_URL, { useNewUrlParser: true, useUnifiedTopology: true })
  .then(() => app.listen(PORT, () => console.log(`Server Running on Port: http://localhost:${PORT}`))) // what to do when we connection is made
  .catch((error) => console.log(`${error} did not connect`)); // what if it goes wrong
mongoose.set('useFindAndModify', false);

We now create schema for our database. Since this is basic crud, we want username, email. we do so by creating user_model.js file inside models folder in root directory.

import mongoose from 'mongoose';

const postSchema = mongoose.Schema({
    firstname: String,
    lastname: String,
    email: { // required field
        type: String,
        required: true
    },
    createdAt: { 
        type: Date,
        default: new Date(),
    },
})

var user_model = mongoose.model('user_model', postSchema);

export default user_model;

After exporting the model, we now import in our functions.js file.

Error messages

import { Mongoose } from 'mongoose';
         ^^^^^^^^
SyntaxError: Named export 'Mongoose' not found. The requested module 'mongoose' is a CommonJS module, which may not support all module.exports as named exports.
CommonJS modules can always be imported via the default export, for example using:

import pkg from 'mongoose';
const { Mongoose } = pkg;