[Solved] Consider this Lambda function triggered by a DynamoDB Stream event that logs the "NewImage" of the... };What will be logged if an item with {"userId": "789", "active": true} is inserted? | DynamoDB

DynamoDB - with Serverless

Consider this Lambda function triggered by a DynamoDB Stream event that logs the "NewImage" of the record:

exports.handler = async (event) => {
  event.Records.forEach(record => {
    console.log(JSON.stringify(record.dynamodb.NewImage));
  });
};

What will be logged if an item with {"userId": "789", "active": true} is inserted?

AAn error because NewImage is undefined on insert

B{"userId":"789","active":true}

Cnull

D{"userId":{"S":"789"},"active":{"BOOL":true}}

Step-by-Step Solution

Solution:

Step 1: Understand DynamoDB Stream record format
NewImage contains the new item in DynamoDB's attribute value format (with types).
Step 2: Analyze the inserted item
The item has a string and a boolean attribute, so NewImage will show {"S":"789"} and {"BOOL":true} respectively.
Final Answer:
{"userId":{"S":"789"},"active":{"BOOL":true}} -> Option D
Quick Check:
NewImage uses DynamoDB attribute types [OK]

Quick Trick: NewImage logs DynamoDB typed attributes [OK]

Common Mistakes:

MISTAKES

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Consider this Lambda function triggered by a DynamoDB Stream event that logs the "NewImage" of the record: