[issue] AWS SDK javascript v3 DynamoDb Client BatchWriteItemCommand

Question

Hello,

my code leads to this error: Cannot read properties of undefined (reading '0') in AWS Lambda (nodeJs 18).

Here comes the related code:

```
import { DynamoDBClient, BatchWriteItemCommand } from "@aws-sdk/client-dynamodb";

const client = new DynamoDBClient({ region: "eu-west-1" });

async function addBuildingRoomEvents(events) {

try {

const exp = Math.round((Date.now() + (2 * 60 * 60) * 1000) / 1000); // seconds

let putRequests = [];

for (const event of events) {

const item = {
                timestamp: event.timestamp,
                uuid: generateUUID(),
                building_room_uuid: event.buildingRoomUuid,
                building_uuid: event.buildingUuid,
                expiration_timestamp: exp,
                event_type: event.eventType,
                event_attribute_name: event.eventAttributeName,
                event_attribute_value: event.eventAttributeValue.toString(),
                hvac_uuid: event.itemUuid
            }

const putRequest = { PutRequest: { Item: item } };
            putRequests.push(putRequest);
        }

const params = {

RequestItems: {
                'event_building_room': putRequests
            }
        };

console.log(`[addBuildingRoomEvents] params: ${JSON.stringify(params)}`);

const response = await client.send(
            new BatchWriteItemCommand(params)
        );

return response;

} catch (err) {

throw err;
    }
}
```

This code creates for instance those params:

```
{
    "RequestItems": {
        "event_building_room": [
            {
                "PutRequest": {
                    "Item": {
                        "timestamp": 1676575456197,
                        "uuid": "ff1493f1-737a-44e70-ya96a-afc30133e5cf",
                        "building_room_uuid": "226c0c82-86ac-445f8-yb1de-3525366f4d61",
                        "building_uuid": "348af157-2177-4bb3-b322-cf8ff2f54d11",
                        "expiration_timestamp": 1676582656,
                        "event_type": "request",
                        "event_attribute_name": "desired_temperature",
                        "event_attribute_value": "10",
                        "hvac_uuid": "e1858b08-0258-4c71-bf9a-d79a1b2de523"
                    }
                }
            },
            {
                "PutRequest": {
                    "Item": {
                        "timestamp": 1676575456197,
                        "uuid": "ecaccce5-8c10-443ee-ybbf9-adab7aaeb7fd",
                        "building_room_uuid": "226c0c82-86ac-445f8-yb1de-3525366f4d61",
                        "building_uuid": "348af157-2177-4bb3-b322-cf8ff2f54d11",
                        "expiration_timestamp": 1676582656,
                        "event_type": "request",
                        "event_attribute_name": "mode",
                        "event_attribute_value": "heat",
                        "hvac_uuid": "e1858b08-0258-4c71-bf9a-d79a1b2de523"
                    }
                }
            },
            {
                "PutRequest": {
                    "Item": {
                        "timestamp": 1676575456197,
                        "uuid": "2f65a6ee-2dec-44153-ya904-8317364ef869",
                        "building_room_uuid": "226c0c82-86ac-445f8-yb1de-3525366f4d61",
                        "building_uuid": "348af157-2177-4bb3-b322-cf8ff2f54d11",
                        "expiration_timestamp": 1676582656,
                        "event_type": "request",
                        "event_attribute_name": "power",
                        "event_attribute_value": "false",
                        "hvac_uuid": "e1858b08-0258-4c71-bf9a-d79a1b2de523"
                    }
                }
            }
        ]
    }
}
```

I suspect that I am supposed to write Json with type specification but I can't figure how to do it.

Thank you for your help.

Accepted Answer

You need to use a higher level client, such as the `Document Client`. Try instantiate your client like below:

```
import { DynamoDBClient, } from "@aws-sdk/client-dynamodb";
import { DynamoDBDocumentClient, BatchWriteCommand} from "@aws-sdk/lib-dynamodb";

const ddb = new DynamoDBClient({ region: "eu-west-1" });
const client = DynamoDBDocumentClient.from(ddb);

...
...
 const response = await client.send(
            new BatchWriteCommand(params)
        );

```

This should allow you to work with native JSON with no issue.

Be sure you have installed the `@aws-sdk/lib-dynamodb` if you do not have the entire `@aws-sdk` package installed.

An example can be seen [here](https://github.com/awsdocs/aws-doc-sdk-examples/blob/main/javascriptv3/example_code/dynamodb/src/movies/writeData.js)

[issue] AWS SDK javascript v3 DynamoDb Client BatchWriteItemCommand

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