node.js - 如何使用nodejs将过滤后的数据从dynamodb导出到csv？

Question

我想将过滤后的数据从 dynamodb 导出到 csv。我有一个使用名称和 ID 过滤数据的功能。现在我需要将过滤后的数据导出到 excel 中。我该如何解决这个问题？我见过这个 npm dynamodb-csv。但这并没有解决我的问题..

标签： node.jsamazon-dynamodb

Answer 1

我正在使用以下代码片段进行导出和导入：

const AWS = require('aws-sdk');
const dynamoDb = new AWS.DynamoDB.DocumentClient({ region: 'eu-central-1' });
const READ_FROM_TABLE = "example-table-prod"
const STORE_TO_TABLE = "example-table-dev"
const fs = require('fs');

async function loadAllResults() {
  var results = []
  var currentResults = await loadAdditionalResults()
  results = results.concat(currentResults.Items)
  while (currentResults.LastEvaluatedKey) {
    currentResults = await loadAdditionalResults(currentResults.LastEvaluatedKey)
    results = results.concat(currentResults.Items)
  }
  fs.writeFile("output.json", JSON.stringify(results, null, 2), () => {
    console.log(results.length)
  })
  return results
}

async function loadAdditionalResults(start) {
  console.log("Loading more results...")
  var params = {
    TableName: READ_FROM_TABLE,
  }

  if (start) {
    params.ExclusiveStartKey = start
  }

  return new Promise((resolve, reject) => {
    dynamoDb.scan(params, (error, result) => {
      if (error) {
        console.log(error);
        reject(error)
      } else if (result) {
        resolve(result)
      } else {
        reject("Unknown error")
      }
    })
  })
}

async function storeAllResults(results) {
  var count = 0
  for (result of results) {
    await storeItem(result)
    count++
    console.log("Stored " + count + " / " + results.length)
  }
}

async function storeItem(item) {
  const params = {
    TableName: STORE_TO_TABLE,
    Item: item
  };

  return new Promise((resolve, reject) => {
    dynamoDb.put(params, function (error, data) {
      if (error) {
        console.log(error);
        reject({ error: 'Could not create item' });
      }
      resolve("Stored");
    });
  });
};

async function main() {
  let results = await loadAllResults()
  storeAllResults(results)
}


main()

随意使用对您有用的任何片段。另请注意，您可以使用https://www.npmjs.com/package/json2csv将 json 转换为 csv