创建 Amazon Lambda 函数 - Amazon SDK for JavaScript
配置开发工具包 扫描 DynamoDB 表捆绑 Lambda 函数
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Amazon SDK for JavaScriptV3 API 参考指南详细描述了Amazon SDK for JavaScript版本 3 (V3) 的所有 API 操作。

本文属于机器翻译版本。若本译文内容与英语原文存在差异，则一律以英文原文为准。

创建 Amazon Lambda 函数

配置开发工具包

首先导入必需Amazon SDK for JavaScript(v3) 模块和命令：DynamoDBClient和 DynamoDBScanCommand, 和SNSClient和 Amazon SNSPublishCommand命令。Replace领域使用Amazon区域。然后计算今天的日期并将其分配给参数。然后创建参数ScanCommand. 替换TABLE_NAME与您在中创建的表的名称一致。创建Amazon资源 这个例子的部分。

下面的代码段演示了此步骤。（有关完整示例，请参阅捆绑 Lambda 函数。）

"use strict";
// Load the required clients and commands.
const { DynamoDBClient, ScanCommand } = require("@aws-sdk/client-dynamodb");
const { SNSClient, PublishCommand } = require("@aws-sdk/client-sns");

//Set the AWS Region.
const REGION = "REGION"; //e.g. "us-east-1"

// Get today's date.
const today = new Date();
const dd = String(today.getDate()).padStart(2, "0");
const mm = String(today.getMonth() + 1).padStart(2, "0"); //January is 0!
const yyyy = today.getFullYear();
const date = yyyy + "-" + mm + "-" + dd;

// Set the parameters for the ScanCommand method.
const params = {
  // Specify which items in the results are returned.
  FilterExpression: "startDate = :topic",
  // Define the expression attribute value, which are substitutes for the values you want to compare.
  ExpressionAttributeValues: {
    ":topic": { S: date },
  },
  // Set the projection expression, which the the attributes that you want.
  ProjectionExpression: "firstName, phone",
  TableName: "TABLE_NAME",
};

扫描 DynamoDB 表

首先创建一个名为的 async/await 函数sendText使用 Amazon SNS 发布短信PublishCommand. 然后，添加try区块模式，该模式可以扫描 DynamoDB 表以查找员工今天的工作周年纪念日，然后调用sendText函数向这些员工发送短信。如果出现错误catch块被称为。

下面的代码段演示了此步骤。（有关完整示例，请参阅捆绑 Lambda 函数。）

exports.handler = async (event, context, callback) => {
  // Helper function to send message using Amazon SNS.
  async function sendText(textParams) {
    try {
      const data = await snsclient.send(new PublishCommand(textParams));
      console.log("Message sent");
    } catch (err) {
      console.log("Error, message not sent ", err);
    }
  }
  try {
    // Scan the table to check identify employees with work anniversary today.
    const data = await dbclient.send(new ScanCommand(params));
    data.Items.forEach(function (element, index, array) {
      const textParams = {
        PhoneNumber: element.phone.N,
        Message:
          "Hi " +
          element.firstName.S +
          "; congratulations on your work anniversary!",
      };
      // Send message using Amazon SNS.
      sendText(textParams);
    });
  } catch (err) {
    console.log("Error, could not scan table ", err);
  }
};

捆绑 Lambda 函数

本主题介绍如何将mylambdafunction.js以及所需Amazon SDK for JavaScript这个例子的模块变成一个名为index.js.

  1. 如果您尚不了解，请按照先决条件项对于这个例子来安装 webpack。

    注意

    有关webpack，请参阅使用 webpack 捆绑应用程序.

  2. 在命令行中运行以下命令以捆绑JavaScript对于这个例子到一个名为的文件<index.js>：

    webpack mylamdbafunction.js --mode development --target node --devtool false --output-library-target umd -o index.js
    重要

    请注意，输出被命名为index.js. 这是因为 Lambda 函数必须有index.js处理程序来工作。

  3. 压缩捆绑的输出文件，index.js，转入名为的 ZIP 文件my-lambda-function.zip.

  4. 上传mylambdafunction.zip转到您在中创建的 Amazon S3 存储桶创建Amazon资源 本教程的主题。

以下是完整的浏览器脚本代码mylambdafunction.js.

"use strict";
// Load the required clients and commands.
const { DynamoDBClient, ScanCommand } = require("@aws-sdk/client-dynamodb");
const { SNSClient, PublishCommand } = require("@aws-sdk/client-sns");

//Set the AWS Region.
const REGION = "REGION"; //e.g. "us-east-1"

// Get today's date.
const today = new Date();
const dd = String(today.getDate()).padStart(2, "0");
const mm = String(today.getMonth() + 1).padStart(2, "0"); //January is 0!
const yyyy = today.getFullYear();
const date = yyyy + "-" + mm + "-" + dd;

// Set the parameters for the ScanCommand method.
const params = {
  // Specify which items in the results are returned.
  FilterExpression: "startDate = :topic",
  // Define the expression attribute value, which are substitutes for the values you want to compare.
  ExpressionAttributeValues: {
    ":topic": { S: date },
  },
  // Set the projection expression, which the the attributes that you want.
  ProjectionExpression: "firstName, phone",
  TableName: "TABLE_NAME",
};

// Create the client service objects.
const dbclient = new DynamoDBClient({ region: REGION });
const snsclient = new SNSClient({ region: REGION });

exports.handler = async (event, context, callback) => {
  // Helper function to send message using Amazon SNS.
  async function sendText(textParams) {
    try {
      const data = await snsclient.send(new PublishCommand(textParams));
      console.log("Message sent");
    } catch (err) {
      console.log("Error, message not sent ", err);
    }
  }
  try {
    // Scan the table to check identify employees with work anniversary today.
    const data = await dbclient.send(new ScanCommand(params));
    data.Items.forEach(function (element, index, array) {
      const textParams = {
        PhoneNumber: element.phone.N,
        Message:
          "Hi " +
          element.firstName.S +
          "; congratulations on your work anniversary!",
      };
      // Send message using Amazon SNS.
      sendText(textParams);
    });
  } catch (err) {
    console.log("Error, could not scan table ", err);
  }
};