dynamodb is being very indecisive for me. I have a random id generator that includes both letters and numbers, but when I use putItem an error appears saying: ValidationException: The parameter cannot be converted to a numeric value: random3string8of5letters4and2numbers.
If I give in and decide to make my id generator number only, it appears with another error: ValidationException: One or more parameter values were invalid: Type mismatch for key user_id expected: S actual: N if I put user_id: "999999"
I am very confused right now. Any help would help :)

Function where weird stuff is happening:

const dynamo = new AWS.DynamoDB();

async function addUser(username, password, email, firstName) {
    const items = {
        "user_id": {
            "N": 2 //or "2" or "j38873kjhad8123" or something like that
                   //normally r() - the random id generator that returns a random id
        },
        "username": {
            "S": username
        },
        "password": {
            "S": password
        },
        "email": {
            "S": email
        },
        "firstName": {
            "S": firstName
        }
    };


    const message = new Promise((res, rej) => {
        dynamo.putItem({
            TableName: 'user_data',
            Item: items 
        }, 
        (err, data) => {
            if (err) rej(err);
            else res({ id: user_id, message: `User added to database with user_id ${user_id}` });
        });
    });
    return message;
}
//example usage of function:
addUser("test", "test", "test", "test").then(...);

random id generator:

function r() { //get randomized string 30 chars long
    let res = '';
    const chars = ["a","b","c","d","e","f","g","h","i","j","k","l","m","n","o","p","q","r","s","t","u","v","w","x","y","z","0","1","2","3","4","5","6","7","8","9"];
    for (let i = 0; i < 30; i  ) {
        res  = chars[Math.floor(Math.random() * chars.length)];
    }
    return res;
}

CodePudding user response：

There are two places that you need to indicate that user_id is a string:

1. in the attribute definitions when creating your table
2. in the item you are passing to the putItem call

It looks like your table definition was correctly configured with user_id as a string so the problem must be in the parameters to your putItem call. Use the following:

"user_id" : { "S": r() }