Amazon Lambda writing to DynamoDB - amazon-web-services

Question

I'm new to dynamoDB and I'm trying to write some data to the table using Lambda.
So far I have this:
'AddFood': function () {
var FoodName = this.event.request.intent.slots.FoodName.value;
var FoodCalories = this.event.request.intent.slots.FoodCalories.value;
console.log('FoodName : ' + FoodName);
const params = {
TableName: 'Foods',
Item: {
'id': {"S": 3},
'calories': {"S": FoodCalories},
'food': {"S": FoodName}
}
};
writeDynamoItem(params, myResult=>{
var say = '';
say = myResult;
say = FoodName + ' with ' + FoodCalories + ' calories has been added ';
this.response.speak(say).listen('try again');
this.emit(':responseReady');
});
function writeDynamoItem(params, callback) {
var AWS = require('aws-sdk');
AWS.config.update({region: AWSregion});
var docClient = new AWS.DynamoDB();
console.log('writing item to DynamoDB table');
docClient.putItem(params, function (err, data) {
if (err) {
callback(err, null)
} else {
callback(null, data)
}
});
}
}
Does anyone know why the data is not appearing in the database?
I have checked the IAM and the policy is set to AmazonDynamoDBFullAccess.

Answer 1

After making a few changes to the write function, the following code allowed me to write items to the database:
function writeDynamoItem(params, callback) {
const AWS = require('aws-sdk');
AWS.config.update({region: AWSregion});
const docClient = new AWS.DynamoDB.DocumentClient({region: 'eu-west-1'});
console.log('writing item to DynamoDB table');
docClient.put(params, function (err, data) {
if (err) {
callback(err, null)
console.error("Unable to write item. Error JSON:", JSON.stringify(err, null, 2))
} else {
callback(null, data)
}
});
}

Answer 2

To write to DynamoDB from a Lambda function (using Python) you must use the boto3 package and load the dynamodb resource:
Hope this helps, it is writing food and calories from the event and writing them with a generated uuid
import boto3
import os
import uuid
def writeToDynamo(event, context):
recordId = str(uuid.uuid4())
voice = event["food"]
text = event["calories"]
print('Generating new DynamoDB record, with ID: ' + recordId)
print('Input food: ' + food)
print('Input calories: ' + calories)
#Creating new record in DynamoDB table
dynamodb = boto3.resource('dynamodb')
table = dynamodb.Table(os.environ['DB_TABLE_NAME'])
table.put_item(
Item={
'id' : recordId,
'food' : food,
'calories' : calories
}
)
return recordId