dynamodb node aws-sdk simple getItem() call - node.js

Question

Folks, New to Javascript... trying to do simple dynamo queries from node:
var AWS = require('aws-sdk');
AWS.config.update({region: 'us-east-1'});
var db = new AWS.DynamoDB();
var params = {
"TableName" : 'admins',
"Key" : [
{ "username" : { "S" : "foo" } },
],
}
db.getItem(params, function(err, data) {
console.log('error: '+ err);
console.log(data);
return next();
res.send(data);
});
}
Output:
error: UnexpectedParameter: Unexpected key 'username' found in params.Key['0']
Thanks! Any help would be greatly appreciated!

Answer 1

Must follow the SDK and Docs, its simple:
http://docs.aws.amazon.com/amazondynamodb/latest/APIReference/API_GetItem.html
var params = {
AttributesToGet: [
"password"
],
TableName : 'foo',
Key : {
"username" : {
"S" : "bar"
}
}
}
db.getItem(params, function(err, data) {
if (err) {
console.log(err); // an error occurred
}
else {
console.log(data); // successful response
res.send(data);
}
return next();
});

Answer 2

I was trying to do it as it was suggested in the documentation, but also got errors.
At the end the following worked:
var aws = require('aws-sdk');
var db = new aws.DynamoDB({
region: 'eu-central-1',
maxRetries: 1
});
exports.handler = event => {
return queryMyThings();
}
const queryMyThings = async (event) => {
var params = {
Key: {
"ColumnByWhichYouSearch": {
S: "ValueThatYouAreQueriing"
}
},
TableName: "YourTableName"
};
return await db.getItem(params).promise();
}

Answer 3

Here are great resources for DynamoDB using NodeJS:
Getting Started guide
Documentaion and examples
If you're using the DocumentClient