Formatting DynamoDB data to normal JSON in Typescript and AWS Lambda-CodePudding

I am retrieving data from DynamoDB using a query and I get the following returned:

[{"serviceUserId":{"S":"123456789"},"createdDate":{"S":"11-12-2021"}}]

The DynamoDB JSON format has the type in in which I am trying to get rid of by converting to a normal JSON format. I have tried using the AWS.DynamoDB.Converter.unmarshall but I am getting an error in my code:

Argument of type 'ItemList' is not assignable to parameter of type "AttributeMap".
  Index signature for type 'string' is missing in type "AttributeMap[]".

Here is my code:

                 if (result.Count > 0) {
                     const newImage = AWS.DynamoDB.Converter.unmarshall(
                        result.Items
                         )
                   console.log('new Image: '   JSON.stringify(newImage));
                    resolve(newImage);
                 } else { 
                     console.log('No record found');
                     reject(err);
                 }

If I remove the [] brackets in the DynamoDB JSON then it is converted successfully, but obviously I cannot do this in my program as the brackets are there for a reason!

Does anyone know how to convert my JSON file to a format that unmarshall will accept?

CodePudding user response：

Map through the items and unmarshal one by one. (un)marshal accepts an object type, not an array.

import { marshall, unmarshall } from '@aws-sdk/util-dynamodb';  // SDK V3, but worked the same in V2

(() => {
  const items = [{ serviceUserId: { S: '123456789' }, createdDate: { S: '11-12-2021' } }];
  
  // from DynamoDB JSON
  const unmarshalled = items.map((i) => unmarshall(i));

  // make the return trip back to DynamoDB JSON
  const marshalled = unmarshalled.map((i) => marshall(i));
})();