Dynamodb trigger to update another dynamobo table using lambda

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I am using dynamodb trigger for my lambda.So i am considering two conditions, whenever my table 1 gets updated lambda should be triggered and based on condition expression table 2 should be updated just like the changes i have applied in table 2. Since i am going to use boto 3 resource need sample logic regrading the same. I am new to handling events with dynamodb triggers. Any help will be highly appreciated.

aws-lambda amazon-web-services
2 Answers

Generally you would setup event source mapping between table 1 and your lambda function.

The lambda function would process the records from table 1, e.g. filter them out based on some condition, and then the remaining records would be written to the table 2.

For writing to table 2, boto3 provides interface to dynamodb.

user_2488230

Table-1 ~~~~~~~~> AWS Lambda --------->Table2

Event received by AWS Lambda will look something like this. What you need to do is based on event name process the values present and store it in Table-2.

def lambda_handler(event, context):
    dynamodb = boto3.resource('dynamodb', region_name='eu-west-1')
    table2 = dynamodb.Table('Table-2')

    # Read the records in the event
    for record in event['Records']:
        # process record and prepare required object for Table-2
        table_2_obj = process_record(record)
        put_item_response = table2.put_item(table_2_obj)
        # Verify the response if required
        print(put_item_response)
user_53589500
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