我將 node.js 與 express 和 sequelize 一起使用，我的數據庫是 mysql。我試圖創建一個類模型，如文檔中所寫：https://sequelize.org/master/manual/model-basics.html。我能夠連接到數據庫，但無法弄清楚如何將模型與數據庫同步以創建表。這是我的用戶模型：const { DataTypes, Model } = require('sequelize');const connection = require("../server");export class User extends Model { }User.init({    id: {        type: DataTypes.BIGINT,        autoIncrement: true,        primaryKey: true,        unique: true,        allowNull: false    },    username: {        type: DataTypes.STRING,        allowNull: false,        unique: true,    },    password: {        type: DataTypes.STRING,        allowNull: false,    },    userType: {        type: DataTypes.STRING,        allowNull: false,    }}, {    connection});這是我的 server.js：const express = require("express");const Sequelize = require("sequelize");const app = express();const port = 8080;const connection = new Sequelize("coupons2", "root", "1234", {    host: "localhost",    dialect: "mysql"})connection.sync()    .then(() => {        console.log("Connection to DB was successful");    })    .catch(err => {        console.error("Unable to connect to DB", err);    });app.listen(port, () => {    console.log(`Server is running on port ${port}`);})module.exports = connection;謝謝你！