尽管能够使用不同的数组写入数据库以 PUT 到数据库，但 DynamoDB 抛出未定义值错误

Question

I have a method that's making a call to a table with the following schema: userId: string | sessionId: string | orders: list Here's the following code:

const marshallOptions = {
    convertEmptyValues: false,
    removeUndefinedValues: false,
    convertClassInstanceToMap: false,
  };
  
const unmarshallOptions = {
    wrapNumbers: false,
  };
  
const translateConfig = { marshallOptions, unmarshallOptions };

const client: DynamoDBClient = new DynamoDBClient({});
const dynamo: DynamoDBDocument = DynamoDBDocument.from(client, translateConfig);

async function handleOrder(event: APIGatewayProxyEventV2): Promise<string> {
    let req: any = JSON.parse(String(event?.body));
    // Get student's orders
    let studentOrderSubmissions: any = await dynamo.send(new GetCommand({
        TableName: orderBook,
        Key: {
            userId: req.userId,
            sessionId: sessionIdPlaceholder
        }
    }))
    let studentOrders: any = studentOrderSubmissions.Item?.orders;
    const orderInfo: OrderInfo = {
        orderNumber: req.orderNumber,
        userId: req.userId,
        price: req.price,
        position: req.position,
        isLong: req.isLong,
        isBuy: req.isBuy,
        quantity: req.quantity,
        closedOut: req.closedOut
    } 
    studentOrders.push(orderInfo);
    const params = {
        TableName: orderBook,
        Item: {
            userId: req.userId,
            sessionId: req.sessionId,
            orders: studentOrders
        }
    };
    await dynamo.put(params, function(err: any, data: any) {
        if (err) {
            console.log("Error", err);
        } 
        else {
            console.log("Success", data);
        }
    });

When modifying the studentOrders array pushing a new student order into it, after trying to PUT the changes into DynamoDb into the OrderBook table, I always get the following error: Pass options.removeUndefinedValues=true to remove undefined values from map/array/set. EVEN after setting marshall options.removeUndefinedValues to false (despite it by default being false).

When I create a new array with the following code:

const testArray: any = [];
testArray.push(orderInfo);

and replace studentOrders with testArray, DynamoDB saves the data and doesn't throw an error. Is this because DynamoDB doesn't allow you to pass in an array from itself? How would one update a list attribute in a table then? If I can't use put or PutCommand that leaves me with the query options and writing a new query but I figured I'd ask more experienced people first if they've ever run into this problem.

Answer 1

Found out what the issue was. My object wasn't undefined. What was undefined was my sort key. It was throwing an error letting me know one of my values being passed into the parameters was undefined but didn't tell me which one specifically: With that being said the error was here:

Item: {
   userId: req.userId,
   sessionId: req.sessionId,
   orders: studentOrders
}

I never defined req.sessionId, SO THAT was what was causing the freak out. It really should've been cannot pass undefined KEY rather than just say that you can't pass an undefined value.