DynamoDB table seed works in cli but not AWS-SDK - amazon-dynamodb

Question

I have a table that has more than 25 items and wrote a basic script to break them into sub arrays of 25 items each then loops thru that collection of sub arrays to run a batch write item command in the AWS DynamoDB Client. The issue I am getting is a returned validation error. When I run the same seed file via the aws-cli it seeds the table perfectly. This makes me think it has something to do with my script. See anything I am missing? Thanks in advance!
var { DynamoDB } = require('aws-sdk');
var db = new DynamoDB.DocumentClient({
region: 'localhost',
endpoint: 'http://localhost:8000',
});
const allItems = require('./allItems.json');
const tableName = 'some-table-name';
console.log({ tableName, allItems });
var batches = [];
var currentBatch = [];
var count = 0;
for (let i = 0; i < allItems.length; i++) {
//push item to the current batch
count++;
currentBatch.push(allItems[i]);
if (count === 25) {
batches.push(currentBatch);
currentBatch = [];
}
}
//if there are still items left in the curr batch, add to the collection of batches
if (currentBatch.length > 0 && currentBatch.length !== 25) {
batches.push(currentBatch);
}
var completedRequests = 0;
var errors = false;
//request handler for DynamoDB
function requestHandler(err, data) {
console.log('In the request handler...');
return function (err, data) {
completedRequests++;
errors = errors ? true : err;
//log error
if (errors) {
console.error('Request caused a DB error.');
console.error('ERROR: ' + err);
console.error(JSON.stringify(err, null, 2));
} else {
var res = {
statusCode: 200,
headers: {
'Content-Type': 'application/json',
'Access-Control-Allow-Methods': 'GET,POST,OPTIONS',
'Access-Control-Allow-Origin': '*',
'Access-Control-Allow-Credentials': true,
},
body: JSON.stringify(data),
isBase64Encoded: false,
};
console.log(`Success: returned ${data}`);
return res;
}
if (completedRequests == batches.length) {
return errors;
}
};
}
//Make request
var params;
for (let j = 0; j < batches.length; j++) {
//items go in params.RequestedItems.id array
//format for the items is {PutRequest : {Item: ITEM_OBJECT}}
params = '{"RequestItems": {"' + tableName + '": []}}';
params = JSON.parse(params);
params.RequestItems[tableName] = batches[j];
console.log('before db.batchWriteItem: ', params);
try {
//send to db
db.batchWrite(params, requestHandler(params));
} catch{
console.error(err)
}
}
Here is the formatted request object and the error:
before db.batchWriteItem:
{ RequestItems:
{ 'some-table-name': [ [Object], [Object], [Object], [Object] ] }
}
In the request handler...
Request caused a DB error.
ERROR: ValidationException: Invalid attribute value type
{
"message": "Invalid attribute value type",
"code": "ValidationException",
"time": "2020-08-04T10:51:13.751Z",
"requestId": "dd49628c-6ee9-4275-9349-6edca29636fd",
"statusCode": 400,
"retryable": false,
"retryDelay": 47.94198279972915
}

Answer 1

You are using the DocumentClient in the nodejs code. This will automatically convert the data format used by DynamoDB to a more easily consumable format.
e.g.
{
"id": {
"S": "A string value"
}
}
would become
{
"id": "A string value"
}
The CLI does not perform this data conversion.
You can use the regular DynamoDB client to not perform this conversion in Nodejs. e.g. const db = new Dynamodb()