使用适用于 DynamoDB 的 AWS-SDK，createSet 创建 Map 而不是 Set

Question

If you were to create a new item and leave an empty list (ie { a: 'string', b: [] } in your params, it'll convert this to a List Attribute. What I actually want is a String Set Attribute, or SS.

I scoured through the documentation more and found createSet and was hopeful this will solve my problem. But unfortunately it created a Map Attribute instead. Currently, this is how I'm creating it:

const aws = require('aws-sdk');

(async () => {
    const docClient = new aws.DynamoDB.DocumentClient();

    const params = {
        TableName: 'some_table_in_dynamodb',
        Item: {
            a: 'some string',
            b: docClient.createSet([])
        }
    };

    const response = await docClient.put(params).promise();
    console.log(response);
})();

Answer 1

I got the solution from playing with the UI on DynamoDB: The list CANNOT be empty, otherwise it'll convert it to a Map attribute. to fix this, just add an empty string.

const aws = require('aws-sdk');

(async () => {
    const docClient = new aws.DynamoDB.DocumentClient();

    const params = {
        TableName: 'some_table_in_dynamodb',
        Item: {
            a: 'some string',
            b: docClient.createSet(['']) // ADD STRING FOR SS ATTRIBUTE
        }
    };

    const response = await docClient.put(params).promise();
    console.log(response);
})();