Question

我想知道是否有更好的方法来更新数组中的现有元素，而不是三次获取数据库。如果您有任何想法，我将不胜感激。谢谢！

    const creatStock = async (symbol, webApiData) => {
      try {
        // reversed array
        const webApiDataReversed = webApiData.reverse();

        const query = { symbol };
        const update = { $addToSet: { data: webApiDataReversed } };
        const options = { upsert: true, new: true };
        // create/update Stock
        const stockResult = await Stock.findOneAndUpdate(query, update, options);
        const lastElement = stockResult.data.length - 1;

        const updatePull = {
          $pull: { data: { date: stockResult.data[lastElement].date } },
        };
        // removes last date from data array
        await Stock.findOneAndUpdate(query, updatePull);
        // update Stock
        await Stock.findOneAndUpdate(query, update);
      } catch (ex) {
        console.log(`creatStock error: ${ex}`.red);
      }
    };

架构

const ChildSchemaData = new mongoose.Schema({
  _id: false,
  date: { type: mongoose.Types.Decimal128 },
  open: { type: mongoose.Types.Decimal128 },
  high: { type: mongoose.Types.Decimal128 },
  low: { type: mongoose.Types.Decimal128 },
  close: { type: mongoose.Types.Decimal128 },
  volume: { type: mongoose.Types.Decimal128 },
});

const ParentSchemaSymbol = new mongoose.Schema({
  symbol: {
    type: String,
    unique: true,
  },
  // Array of subdocuments
  data: [ChildSchemaData],
});

module.exports.Stock = mongoose.model('Stock', ParentSchemaSymbol);

输出

Answer 1

好吧，如果您不需要返回更新的文档，请尝试执行此操作-这将仅返回写入结果，并且可以通过一个DB调用来实现：

const creatStock = async (symbol, webApiData) => {
    try {
        // reversed array
        const webApiDataReversed = webApiData.reverse();
        const query = { symbol };

        await Stock.bulkWrite([
            {
                updateOne:
                {
                    "filter": query,
                    "update": { $pop: { data: 1 } }
                }
            }, {
                updateOne:
                {
                    "filter": query,
                    "update": {
                        $addToSet: {
                            data: webApiDataReversed
                        }
                    }
                }
            }
        ])
    } catch (ex) {
        console.log(`creatStock error: ${ex}`.red);
    }
};

参考： mongoDB bulkWrite

Answer 2

您可以这样操作：

  const creatStock = async (symbol, webApiData) => {
  try {
    // reversed array
    const webApiDataReversed = webApiData.reverse();

    const query = { symbol };

    let stock =  await Stock.findOne(query);
    if(stock){
       let stockData = JSON.parse(JSON.stringify(stock.data));
       if(stockData.length>0){
          stockData.pop(); 
       }
       stockData.concat(webApiDataReversed);
       stock.data = stockData;
       await stock.save();
    }
  } catch (ex) {
      console.log(`creatStock error: ${ex}`.red);
  }

猫鼬：如何更新数组中的现有元素？

2 个答案: