৪। মডেল তৈরি করা

// models/User.js
const { DataTypes, Model } = require("sequelize");
const { sequelize } = require("../config/database");  // Correctly import the sequelize instance

class User extends Model {}

// Initialize the User model
User.init(
  {
    username: {
      type: DataTypes.STRING,
      allowNull: false,
    },
    email: {
      type: DataTypes.STRING,
      allowNull: false,
      unique: true,
    },
    password: {
      type: DataTypes.STRING,
      allowNull: false,
    },
  },
  {
    sequelize, // Pass the sequelize instance here
    modelName: "User", // Define the model name
    tableName: "users", // Define the table name
    timestamps: true,  // Automatically adds `createdAt` and `updatedAt` fields
  }
);

module.exports = User;

// database.js ফাইলে
const User = require("../models/User"); // মডেল আমদানি করা

// সমস্ত মডেল সিঙ্ক করার জন্য ফাংশন তৈরি করা
async function syncModels() {
  try {
    // Import models after sequelize instance is created
    const User = require("../models/User");  // Import User model here

    await sequelize.sync({ alter: true });  // Sync models and create/update tables
    console.log("All models were synchronized successfully.");
  } catch (error) {
    console.error("Error synchronizing models:", error);
  }
}

module.exports = { sequelize, connect, syncModels };

const app = require("./app");
const config = require("./config/config");
const { connect, syncModels } = require("./config/database");

async function startServer() {
    const isDbConnected = await connect();
  
    // ডাটাবেস কানেকশন সফল হলে মডেল সিঙ্ক করা
    if (isDbConnected) {
      await syncModels(); // ডাটাবেসে টেবিল সিঙ্ক করা
      app.listen(config.port, () => {
        console.log(`Server is running on port ${config.port}`);
      });
    } else {
      console.error("Failed to start server: Database connection failed.");
    }
  }

// সার্ভার চালু ফাংশন কল করা
startServer();

your-project/
├── config/
│   ├── config.js
│   ├── database.js
├── models/
│   └── User.js
├── app.js
├── server.js
└── .env