添加到购物车不工作Nodejs Expressjs Mysql

这是controller中products.js的代码

let cart = [];

function addToProduct(products) {
  cart.push(products);
}

exports.addToCart = (req, res) => {
  const productId = req.params.id;
  const sql = `SELECT * FROM products WHERE id = ${productId}`;
  connection.query(sql, (error, result) => {
    if (error) {
      return res.send('Error adding to cart');
    } else {
      res.redirect('/allProducts');
      addToProduct(result);
      console.log("length of cart is"+cart.length);
      for(let i= 0; i < cart.length; i++) {
        console.log(cart[i]);
      }
    }
  });
};

function getProducts() {
  return cart.map(product => ({
    name: product.name,
    description: product.description,
    price: product.price,
    stock: product.stock
  }));

}

function getTotal() {
  return cart.reduce((total, product) => total + product.price * product.stock, 0);
}


exports.getCart = (req, res, next) => {
  const products = getProducts();
  const total = getTotal();
  req.cart = { products, total };
  return next();
};

这是routes中pages.js的代码

router.post('/add-to-cart/:id', productsController.addToCart);


router.get('/cart', productsController.getCart, (req, res) => {
  res.render('cart', {
    products: req.cart.products,
    total: req.cart.total
  });
});

现在我没有把产品放进我的车里。bs它只是空的，没有显示错误。Exports.addtocart工作正常，但问题是在那之后。请帮我认出它。

我尝试了很多事情，但最终还是在这里