Trying to write to AWS dynamo db via api - aws-lambda

Question

I am new to AWS and I've slowly been trying to perform different actions. I recently set up an API that allows me to query a dynamodb table and now I am trying to set up an api that will allow me to update a value in the table with the current temperature. This data will come from a script running on a raspberry pi.
I've been wading through so many tutorials but I haven't gotten this quite locked down. I am able to write to the db using a hard-coded python script so I know my db and roles is set up correctly. I am now trying to create a node-based lambda function that will accept parms from the URL and put the values into the table. I am missing something.
First, do I need to map the values in the api? Some guides do it, others do not. Like I said, ideally I want to pass them in as URL parms.
const AWS = require('aws-sdk');
const dynamodb = new AWS.DynamoDB({apiVersion: '2012-08-10'});
exports.handler = (event, context, callback) => {
dynamodb.putItem({
TableName: "temperature",
Item: {
"tempid": {
S: event.queryStringParameters["tempid"]
}
}
}, function(err, data) {
if (err) {
console.log(err, err.stack);
callback(null, {
statusCode: '500',
body: err
});
} else {
callback(null, {
statusCode: '200',
body: 'Result from ' + event.queryStringParameters["tempid"] + '!'
});
}
})
};
When I test it in the api using "tempid=hotttub1" in the query string I get this error:
START RequestId: 1beb4572-65bf-4ab8-81a0-c217677c3acc Version: $LATEST
2020-07-09T14:02:05.773Z 1beb4572-65bf-4ab8-81a0-c217677c3acc INFO { tempid: 'hottub1' }
2020-07-09T14:02:05.774Z 1beb4572-65bf-4ab8-81a0-c217677c3acc ERROR Invoke Error {"errorType":"TypeError","errorMessage":"Cannot read property 'tempid' of undefined","stack":["TypeError: Cannot read property 'tempid' of undefined"," at Runtime.exports.handler (/var/task/index.js:11:47)"," at Runtime.handleOnce (/var/runtime/Runtime.js:66:25)"]}
EDIT
If I print out event I can see that the value is coming in and I am apparently referencing it wrong. Still looking.
{
"tempid": "hottub1"
}

Answer 1

It needed to be in this format:
const AWS = require('aws-sdk');
const dynamodb = new AWS.DynamoDB({apiVersion: '2012-08-10'});
exports.handler = (event, context, callback) => {
console.info("EVENT\n" + JSON.stringify(event.tempid, null, 2))
var temperatureid = JSON.stringify(event.tempid, null, 2)
dynamodb.putItem({
TableName: "temperature",
Item: {
"tempid": {
S: temperatureid
}
}