使用Sequelize根据请求正文中的项数创建动态where子句？

const express = require('express');
const bodyParser = require('body-parser');
const { Sequelize, DataTypes } = require('sequelize');

// 初始化Sequelize
const sequelize = new Sequelize('database', 'username', 'password', {
  host: 'localhost',
  dialect: 'mysql',
});

// 定义模型
const User = sequelize.define('User', {
  name: {
    type: DataTypes.STRING,
    allowNull: false,
  },
  age: {
    type: DataTypes.INTEGER,
    allowNull: false,
  },
});

// 创建Express应用
const app = express();

// 解析请求正文
app.use(bodyParser.json());

// 处理查询请求
app.post('/users', async (req, res) => {
  // 解析请求正文对象
  const { name, age } = req.body;

  // 构建动态查询条件
  let where = {};
  if (name) {
    where.name = name;
  }
  if (age) {
    where.age = age;
  }

  try {
    // 执行查询
    const users = await User.findAll({
      where,
    });

    res.json(users);
  } catch (error) {
    res.status(500).json({ error: 'Internal server error' });
  }
});

// 启动应用
app.listen(3000, () => {
  console.log('Server is running on port 3000');
});