How do I connect an AI chatbot to a database for personalized answers?

<!-- BEGIN COPY / PASTE -->
    const express = require('express');
    const app = express();
    const mysql = require('mysql');

    const db = mysql.createConnection({
      host: 'localhost',
      user: 'user',
      password: 'password',
      database: 'chatbot_db'
    });

    app.post('/webhook', (req, res) => {
      const userId = req.body.userId;
      db.query('SELECT * FROM users WHERE id = ?', [userId], (error, results) => {
        if (error) throw error;
        const personalizedResponse = `Hello ${results[0].name}, how can I assist you today?`;
        res.json({ fulfillmentText: personalizedResponse });
      });
    });

    app.listen(3000, () => console.log('Server is running on port 3000'));
    <!-- END COPY / PASTE -->