批量计算新购优惠

const Big = require('big.js');

function calculateDiscount(originalPrice, discountRate) {
    const bigOriginalPrice = new Big(originalPrice);
    const bigDiscountRate = new Big(discountRate);
    return bigOriginalPrice.times(bigDiscountRate).toFixed(2);
}

BEGIN TRANSACTION;
UPDATE orders SET status = 'processed', discount = calculated_discount WHERE id = order_id;
COMMIT;

const express = require('express');
const app = express();
const Big = require('big.js');

app.use(express.json());

app.post('/calculate-discount', (req, res) => {
    const { originalPrice, discountRate } = req.body;
    const discountedPrice = calculateDiscount(originalPrice, discountRate);
    res.json({ discountedPrice });
});

function calculateDiscount(originalPrice, discountRate) {
    const bigOriginalPrice = new Big(originalPrice);
    const bigDiscountRate = new Big(discountRate);
    return bigOriginalPrice.times(bigDiscountRate).toFixed(2);
}

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