我们还可以使用固定链接为多个产品指定每个产品的数量吗？

CREATE TABLE products (
    id INT PRIMARY KEY,
    name VARCHAR(255),
    quantity INT
);

const express = require('express');
const app = express();
const bodyParser = require('body-parser');
const db = require('./db'); // 假设这是一个数据库连接模块

app.use(bodyParser.json());

// 获取所有产品及其数量
app.get('/products', async (req, res) => {
    try {
        const products = await db.query('SELECT * FROM products');
        res.json(products);
    } catch (error) {
        res.status(500).json({ error: error.message });
    }
});

// 更新某个产品的数量
app.put('/products/:id', async (req, res) => {
    const { id } = req.params;
    const { quantity } = req.body;
    try {
        await db.query('UPDATE products SET quantity = ? WHERE id = ?', [quantity, id]);
        res.json({ message: 'Product quantity updated successfully' });
    } catch (error) {
        res.status(500).json({ error: error.message });
    }
});

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

app.put('/products/:id', async (req, res) => {
    const { id } = req.params;
    const { quantity } = req.body;
    try {
        await db.transaction(async trx => {
            await trx.query('UPDATE products SET quantity = ? WHERE id = ?', [quantity, id]);
        });
        res.json({ message: 'Product quantity updated successfully' });
    } catch (error) {
        res.status(500).json({ error: error.message });
    }
});