Connecting MySQL to your node sequilize application

Goal
To successfully connect our node application to mysql using sequilize adapter.

Prerequisites

To follow this artice along with me effectively:

You will need to have Node.js installed on your computer.
A basic understanding of Node.js.
A suitable code editor. I will go with Visual Studio Code.

Packages

npm i -s dot-env sequelize express cors

Start by defining our database credentials in my .env and install .env

.env

DB_HOST="localhost"
DB_USER="root"
DB_PW="root"
DB_NAME="youtube"

We access the values in the .env file by firstly requiring dotenv in our db config file like so.

config.js

require("dotenv").config({ path: ".env" });

module.exports = {
  HOST: process.env.DB_HOST,
  USER: process.env.DB_USER,
  PASSWORD: process.env.DB_PW,
  DB: process.env.DB_NAME,
  dialect: "mysql",
  pool: {
    max: 5,
    min: 0,
    acquire: 30000,
    idle: 10000,
  },
};

Models

module.exports = (sequelize, Sequelize) => {
  const Channel = sequelize.define("channel", {
    id: {
      type: Sequelize.STRING,
      primaryKey: true,
    },
    channel_name: {
      type: Sequelize.STRING,
    },
  });

  return Channel;
};

Controllers

const db = require("../models");
const Channel = db.channels;
const Op = db.Sequelize.Op;

// Create and Save a new Channel
exports.create = (req, res) => {
  // Validate request
  if (!req.body.channel_name) {
    res.status(400).send({
      message: "Content can not be empty!",
    });
    return;
  }

  // Create a Channel
  const channel = {
    channel_name: req.body.channel_name,
  };

  // Save Channel in the database
  Channel.create(channel)
    .then((data) => {
      res.send(data);
    })
    .catch((err) => {
      res.status(500).send({
        message:
          err.message || "Some error occurred while creating the Channel.",
      });
    });
};

Routers

module.exports = (app) => {
  const channels = require("../controllers/channel.controller.js");

  var router = require("express").Router();

  // Create a new Tutorial
  router.post("/", channels.create);

  // Delete all channels
  router.delete("/", channels.deleteAll);

  app.use("/api/channels", router);
};

Main Server

const express = require("express");
const cors = require("cors");

const app = express();

var corsOptions = {
  origin: "http://localhost:8081",
};
app.use(morgan("tiny"));

app.use(cors(corsOptions));

// parse requests of content-type - application/json
app.use(express.json());

// parse requests of content-type - application/x-www-form-urlencoded
app.use(express.urlencoded({ extended: true }));

const db = require("./app/models");

db.sequelize
  .sync()
  .then(() => {
    console.log("Synced db.");
  })
  .catch((err) => {
    console.log("Failed to sync db: " + err.message);
  });

require("./app/routes/channel.routes")(app);

// set port, listen for requests
const PORT = process.env.PORT || 8080;
app.listen(PORT, () => {
  console.log(`Server is running on port ${PORT}.`);
});

module.exports = app;

we run the application by

node server.js