ddb example

var params = {
    Key: { cognitoId:{ S: cognitoId } },
    TableName: "people",
    UpdateExpression: "SET #attrName =:attrValue",
    ExpressionAttributeNames : {
        "#attrName" : "cheater"
    },
    ExpressionAttributeValues : {
        ":attrValue" : {
            "S" : "TRUE"
        }
    }
};
dynamo.updateItem(params, function(err, data) {
    if (err) {
        console.log("Oops!");
        console.log(err, err.stack);
    }
    cb();
});