Setting Up a Node.js Development Environment with MySQL, Sequelize, and TypeScript

Why Node.js with MySQL and Sequelize?

Node.js is a powerful backend technology, and MySQL remains a popular relational database for many applications. Pairing it with Sequelize ORM simplifies database interactions, and TypeScript ensures type safety, improving developer productivity and reducing bugs.

Now, let's get hands-on.

Getting Started

Step 1: Setting Up the Project

mkdir node-mysql-sequelize-ts
cd node-mysql-sequelize-ts
npm init -y

Step 2: Install Dependencies

Install the required packages:

npm install express sequelize mysql2
npm install --save-dev typescript @types/node @types/express ts-node nodemon

Step 3: Configure TypeScript

Generate a tsconfig.json:

tsc --init

Update the configuration:

{
  "compilerOptions": {
    "target": "ES6",
    "module": "CommonJS",
    "outDir": "./dist",
    "rootDir": "./src",
    "strict": true,
    "esModuleInterop": true
  }
}

Step 4: Setting Up Sequelize

Create a src/config/database.ts file:

import { Sequelize } from "sequelize";

const sequelize = new Sequelize("database_name", "username", "password", {
  host: "localhost",
  dialect: "mysql",
});

export default sequelize;

Step 5: Model Definition

Create src/models/User.ts:

import { DataTypes, Model } from "sequelize";
import sequelize from "../config/database";

class User extends Model {}

User.init(
  {
    id: {
      type: DataTypes.INTEGER,
      autoIncrement: true,
      primaryKey: true,
    },
    name: {
      type: DataTypes.STRING,
      allowNull: false,
    },
    email: {
      type: DataTypes.STRING,
      allowNull: false,
      unique: true,
    },
  },
  {
    sequelize,
    tableName: "users",
  }
);

export default User;

Step 6: Connecting Sequelize with the App

Database Sync
In src/index.ts, synchronize Sequelize models:

import sequelize from "./config/database";
import User from "./models/User";

const start = async () => {
  try {
    await sequelize.sync({ force: true }); // Creates tables
    console.log("Database synchronized!");
  } catch (error) {
    console.error("Error syncing database:", error);
  }
};

start();

*Step 6: Testing the Setup *

Add a Basic Route
Update src/index.ts to include a test route:

import express, { Request, Response } from "express";
import sequelize from "./config/database";
import User from "./models/User";

const app = express();
const port = 3000;

app.get("/", async (req: Request, res: Response) => {
  try {
    const users = await User.findAll();
    res.json(users);
  } catch (error) {
    res.status(500).send("Database error");
  }
});

app.listen(port, async () => {
  console.log(`Server running on http://localhost:${port}`);
  await sequelize.authenticate();
});

Start the development server:

npm run dev