当我点击提交时递增字段user.entries

CREATE TABLE users (
    id INT AUTO_INCREMENT PRIMARY KEY,
    username VARCHAR(255) NOT NULL,
    entries INT DEFAULT 0
);

const express = require('express');
const mysql = require('mysql');
const app = express();

// 创建数据库连接
const db = mysql.createConnection({
    host: 'localhost',
    user: 'your_username',
    password: 'your_password',
    database: 'your_database'
});

db.connect((err) => {
    if (err) throw err;
    console.log('Database connected!');
});

app.use(express.json());

app.post('/submit', (req, res) => {
    const userId = req.body.userId; // 假设从前端获取用户ID

    const sql = 'UPDATE users SET entries = entries + 1 WHERE id = ?';
    db.query(sql, [userId], (err, result) => {
        if (err) throw err;
        res.send('Entries incremented successfully!');
    });
});

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

START TRANSACTION;
UPDATE users SET entries = entries + 1 WHERE id = ?;
COMMIT;