javascript - .then 内的 Mongoose 查询，尽管工作正常但仍收到警告和错误

Question

在阅读了关于是否可以在 promise 句柄中执行 Mongoose 查询的文档后，我有点困惑。在本例中，我尝试循环portfolio.coin 中的一组对象，然后在另一个模型中查找它们的当前价格。有一个更好的方法吗？以下代码有效，但我收到 Unhandledpromiserejection 警告和 documentnotfound 错误。

// @route:       GET api/portfolio/
// @description: Get the latest portfolio with price changes
// @access:      Private
router.get('/', passport.authenticate('jwt',
  { session: false }), (req, res) => {
    Portfolio.findOne({
      user: req.user.id
    }).then(portfolio => {
      if (portfolio) {
        // Loop over all the coins in the portfolio
        portfolio.coin.forEach((item, index) => {

          // In scope object 
          let details = {
            _id: item._id,
            exchange: item.exchange,
            currencyname: item.currencyname,
            currencyquantity: item.currencyquantity,
            currencypaidwith: item.currencypaidwith,
            pricepaid: item.pricepaid,
            currentprice: 0,
            pricedifference: 0
          };

          // For each coin find the market prices
          Market.findOne({
            exchange: item.exchange,
            coin_one: item.currencyname,
            coin_two: item.currencypaidwith
          }).then(result => {
            if (result) {

              // details
              details.currentprice = result.price;
              details.pricedifference = result.price; // TODO: percentage 
              portfolio.coin[index] = details;

              if (portfolio.coin.length >= index) {
                portfolio.save().then(portfolio => res.json(portfolio)).catch(err => res.status(404).json({ nodoc: "somethin went wrong" }));
              }
            }
          }).catch(err => res.status(404).json({ nodoc: "could not find a doc" }))
        });
      }
    })
  })

Answer 1

您需要在最后一行添加.catch

// @route:       GET api/portfolio/
// @description: Get the latest portfolio with price changes
// @access:      Private
router.get('/', passport.authenticate('jwt',
{ session: false }), (req, res) => {
    Portfolio.findOne({
    user: req.user.id
    }).then(portfolio => {
    if (portfolio) {
        // Loop over all the coins in the portfolio
        portfolio.coin.forEach((item, index) => {

        // In scope object 
        let details = {
            _id: item._id,
            exchange: item.exchange,
            currencyname: item.currencyname,
            currencyquantity: item.currencyquantity,
            currencypaidwith: item.currencypaidwith,
            pricepaid: item.pricepaid,
            currentprice: 0,
            pricedifference: 0
        };

        // For each coin find the market prices
        Market.findOne({
            exchange: item.exchange,
            coin_one: item.currencyname,
            coin_two: item.currencypaidwith
        }).then(result => {
            if (result) {

            // details
            details.currentprice = result.price;
            details.pricedifference = result.price; // TODO: percentage 
            portfolio.coin[index] = details;

            if (portfolio.coin.length >= index) {
                portfolio.save().then(portfolio => res.json(portfolio)).catch(err => res.status(404).json({ nodoc: "somethin went wrong" }));
            }
            }
        }).catch(err => res.status(404).json({ nodoc: "could not find a doc" }))
        });
    }
    }).catch(err => res.status(404).json({ nodoc: "could not find a portfolio" }))
})