bhupendra-chouhan/contact-manager

This is a MERN stack based mini project

Basic Backend Folder Structure:

• .env
• package.json
• package-lock.json
• extras: (Readme.md, .git, lint, prettier, etc)

/src

• index.js (db connects)
• App.js (config, cookie, url_encode)
• constants.js (enums, db_name)

/db (contains db_calls) /models (contains db_schema_structure) /controllers (contains functions) /routes (contains url_paths) /middlewares /utils (contains code/functions which can be used in many places throughout the project) /more (depends)

Step to setup backend server using ExpressJS and NodeJS:

1. Initialise package.json using command : npm init

// package.json

{
  "name": "mycontacts-backend-api",
  "version": "1.0.0",
  "description": "This is a express project for my contacts backend api",
  "main": "server.js",
  "scripts": {
    "test": "echo \"Error: no test specified\" && exit 1"
  },
  "repository": {
    "type": "git",
    "url": "git+https://github.com/Bhupendrachouhan19/contact-manager.git"
  },
  "keywords": [
    "contact-manager"
  ],
  "author": "Bhupendra Chouhan",
  "license": "MIT",
  "bugs": {
    "url": "https://github.com/Bhupendrachouhan19/contact-manager/issues"
  },
  "homepage": "https://github.com/Bhupendrachouhan19/contact-manager#readme"
}

2. Create .gitignore, server.js, README.md files in the root directory.

3. Install ExpressJS package using command: npm install express

4. Install Nodemon package as a Dev-dependency(It restarts the server whenever we make any changes to our application) using command: npm install -D nodemon

5. Create an Express Server:

// server.js

const express = require("express");

const app = express();

const port = 5000;

app.get('/', (req, res)=>{
    res.send('Hello World!!!');
})

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

6. Set up the environmental variables inside the .env file:
   • Install the donenv package using command: npm install dotenv
   • As we have installed dotenv, this will allow us to fetch the value of the port from the .env file, with the help of a module name 'process' (It's a core module of node.js).

// .env

PORT=5001

7. Serperate the API routes on NodeJS and Express
8. Setting up the Controller which contains the logic all to our CRUD request connection to our database.

---

What are Middlewares in the backend?

• It is those methods/functions/operations that are called BETWEEN processing the Request and sending the Response in your application method.
• Express provides you with middleware to deal with the (incoming) data (object) in the body of the request.
• Every middleware(declared as app.use()) gets executed sequentially, top-to-bottom as mentioned in the server.js file.

What are a Schema Diagrams?

• Database schema is the logical:
  • View of the entire database.
  • These schema are obviously going to represent
  • In Mongoose, a single model can have multiple schemas, but typically, a model is associated with a single schema. This allows for consistency and clarity in defining the structure of documents stored in a MongoDB collection. However, in more complex scenarios, you might have a need to define multiple schemas for a single model, such as when dealing with inheritance or dynamic schemas.
  • A single database in MongoDB can have an unlimited number of models, each representing a different collection.