使用 node.js 和 aws lambda 将 Alexa 技能连接到 mysql 数据库

Question

我正在尝试使用 AWS Lambda 中的 node.js 将我的 Alexa 技能连接到 Amazon RDS mySQL 数据库。我在将连接上传到 lambda 之前对其进行了测试，它可以正常工作，但是当我上传它时，我收到“完成请求之前退出进程”或“技能响应有问题”错误。

'use strict';
const Alexa = require('alexa-sdk');

const APP_ID = 'amzn1.ask.skill.11069fc0-53bc-4cd0-8961-dd41e2d812f8';

var testSQL = 'SELECT weight, height from users where pin=1100';
//=========================================================================================================================================
//Database connection settings
//=========================================================================================================================================
var mysql = require('mysql');
var config = require('./config.json');
// Add connection details for dB
var pool  = mysql.createPool({
    host     : config.dbhost,
    user     : config.dbuser,
    password : config.dbpassword,
    database : config.dbname
  });

// var dbHeight, dbWeight, dbMuscle, dbExerciseOne, dbExerciseTwo, dbExerciseThree, dbExerciseFour; 
var dbResult;

function searchDB(quest) {
    pool.getConnection(function(err, connection) {
      // Use the connection
        console.log(quest);
        connection.query(quest, function (error, results, fields) {
            // And done with the connection.
            connection.release();
            // Handle error after the release.
            if (!!error) {
                console.log('error')
            }
            else {
                console.log(results[0]);
                dbResult = results[0];
                return dbResult;
                console.log(dbResult.height);
            }
            process.exit();
        });
    });
};

//searchDB(testSQL);

//=========================================================================================================================================
//TODO: The items below this comment need your attention.
//=========================================================================================================================================



const SKILL_NAME = 'My Application';
const GET_FACT_MESSAGE = "Here's your fact: ";
const HELP_MESSAGE = 'You can say tell me a space fact, or, you can say exit... What can I help you with?';
const HELP_REPROMPT = 'What can I help you with?';
const STOP_MESSAGE = 'Goodbye!';

var name, pinNumber;


//=========================================================================================================================================
//Editing anything below this line might break your skill.
//=========================================================================================================================================

const handlers = {
    'LaunchRequest': function () {
        if(Object.keys(this.attributes).length === 0){
            this.attributes.userInfo = {
                'userName': '',
                'pinNo': 0
                }
            this.emit('GetPinIntent');
        }
        else{

            name = this.attributes.userInfo.userName;
            pinNumber = this.attributes.userInfo.pinNo;
            var sql = "";
            //var result = searchDB(sql);
            //var uWeight = result.weight;
            //var uHeight = result.height;
            var speechOutput = 'Welcome ' + name + 'Please select an option: Check My BMI, Create Exercise Plan, Create Meal Plan, Update Height and Weight, Update workout status?';
            this.emit(':ask', speechOutput);
        }
    },

    'GetPinIntent': function (){
      this.emit(':ask','Welcome to my Application, as this is your first time please say your name followed by your pin. For example, my name is Jason and my pin is zero one zero one');
      //this.emit(':responseReady');
   },

    'RememberNameID': function (){
        var filledSlots = delegateSlotCollection.call(this);
        this.attributes.userInfo.userName = this.event.request.intent.slots.name.value;
        this.attributes.userInfo.pinNo = this.event.request.intent.slots.pin.value;

        var speechOutput = 'Welcome ' + this.attributes.userInfo.userName + ' we have stored your Pin Number and we will call you by name next time. Please select an option: BMI or exercise';

        this.response.speak(speechOutput);
        this.emit(':responseReady');

    },

    'CheckBMI': function(){

        var sql = 'SELECT height, weight FROM users WHERE pin=' + this.attributes.userInfo.pinNo;
        var heightWeight = searchDB(sql);
        dbHeight = parseInt(heightWeight.height);
        dbWeight = parseInt(heightWeight.weight);
        var speechOutput = bmiCalculator(dbHeight, dbWeight);
        this.emit(':ask', speechOutput);  

    },

    'AMAZON.HelpIntent': function () {
        const speechOutput = HELP_MESSAGE;
        const reprompt = HELP_REPROMPT;

        this.response.speak(speechOutput).listen(reprompt);
        this.emit(':responseReady');
    },
    'AMAZON.CancelIntent': function () {
        this.response.speak(STOP_MESSAGE);
        this.emit(':responseReady');
    },
    'AMAZON.StopIntent': function () {
        this.response.speak(STOP_MESSAGE);
        this.emit(':responseReady');
    },
    'SessionEndedRequest': function() {
        console.log('session ended!');
        this.emit(':saveState', true);
    }
};

exports.handler = function (event, context, callback) {
    var alexa = Alexa.handler(event, context, callback);
    alexa.APP_ID = APP_ID;
    alexa.dynamoDBTableName = 'fitnessDB';
    alexa.registerHandlers(handlers);
    alexa.execute();


};

function delegateSlotCollection(){
  console.log("in delegateSlotCollection");
  console.log("current dialogState: "+this.event.request.dialogState);
    if (this.event.request.dialogState === "STARTED") {
      console.log("in Beginning");
      var updatedIntent=this.event.request.intent;
      //optionally pre-fill slots: update the intent object with slot values for which
      //you have defaults, then return Dialog.Delegate with this updated intent
      // in the updatedIntent property
      this.emit(":delegate", updatedIntent);
    } else if (this.event.request.dialogState !== "COMPLETED") {
      console.log("in not completed");
      // return a Dialog.Delegate directive with no updatedIntent property.
      this.emit(":delegate");
    } else {
      console.log("in completed");
      console.log("returning: "+ JSON.stringify(this.event.request.intent));
      // Dialog is now complete and all required slots should be filled,
      // so call your normal intent handler.
      return this.event.request.intent;
    }
};
function bmiCalculator (userHeight, userWeight ) {


        var speechOutput = " "; 

        var h = userHeight/100;

        var calcBMI = 0;
        calcBMI = userWeight / (h*h);
        calcBMI = calcBMI.toFixed(2);


        if (calcBMI < 18.5) {
            speechOutput += "Based on your weight of " +weight+ " kilograms and your height of " + height + " metres, your BMI is " +calcBMI+ ". Meaning you are currently underweight.";
            speechOutput += " I would advise you to increase your calorie intake, whilst remaining active.";
            return speechOutput;

        }
        else if (calcBMI >=18.5 && calcBMI < 25){

            speechOutput += "Based on your weight of " +weight+ " kilograms and your height of" + height + " metres, your BMI is " +calcBMI+ ". Meaning you are currently at a normal weight.";
            speechOutput += " I would advise you to stay as you are but ensure you keep a healthy diet and lifestyle to avoid falling above or below this.";
            this.response.speak(speechOutput);
            return speechOutput;
        }
        else if (calcBMI >=25 && calcBMI < 29.9){

            speechOutput += "Based on your weight of " +weight+ " kilograms and your height of" + height + " metres, your BMI is " +calcBMI+ ". Meaning you are currently overweight.";
            speechOutput += " I would advise you to exercise more to fall below this range. A healthy BMI is ranged between 18.5 and 24.9";
            this.response.speak(speechOutput);
            return speechOutput;
        }
        else{

            speechOutput += "Based on your weight of " +weight+ " kilograms and your height of" + height + " metres, your BMI is " +calcBMI+ ". Meaning you are currently obese.";
            speechOutput += " I would advise you to reduce your calorie intake, eat more healthy and exercise more. A healthy BMI is ranged between 18.5 and 24.9";
            return speechOutput;

        }


 };

代码概述了我的数据库连接。我将连接查询创建为一个函数，因为我需要根据上下文对数据库进行不同的查询。有没有办法在exports.handler 函数中创建一个只在需要时调用查询的函数？ 或者有没有其他关于以这种方式连接到数据库的解决方案。

Answer 1

您遇到了多个问题，没有使用 Promise 或 await，您的调用正在异步运行，并且您永远不会立即从 RDS 中获得 lambda 调用的答案。您需要创建一个函数，该函数将在继续其逻辑之前等待答案。 您将遇到的另一个问题是 MySQL RDS 实例是否持续运行，可能存在冷启动问题。 最后一件事是在 AWS lambda 控制台中确保分配足够的计算资源和运行此函数的时间默认 128 mb 的内存和运行函数的时间可以调整以提高性能

Answer 2

使用sync-mysql 对mysql 数据库进行同步查询。它对我有用。