Firebase RealtimeDB to Google Sheets through AppScript - firebase

Question

I am trying to write Firebase RealtimeDB data into a Google Sheets spreadsheet through Google Appscript.
This is what my RealtimeDB looks like:
My goal is
I have tried the following code snippet:
function writeSheets() {
var firebaseUrl = "https://<mydatabase>.firebaseio.com/Attendees";
var base = FirebaseApp.getDatabaseByUrl(firebaseUrl);
var data = base.getData();
var ss = SpreadsheetApp.openById("<mySheet>");
var sheet = ss.getSheetByName("Sheet1");
var num = 2;
range = ss.getRange("A"+num+":B"+num+"");
for(var i in data) {
var values = [[ data[i].ID, data[i].Name ] ];
range.setValues(values);
num += 1;
range = sheet.getRange("A"+num+":B"+num+"");
}
console.log(JSON.stringify(data));
}
It seems to print empty cells into Google Sheet. Not exactly sure why.
Any input would be greatly appreciated. Thanks.
EDIT:
Console Log :
[20-04-08 20:46:26:102 HKT] TypeError: Cannot read property 'ID' of null
at writeSheets(Code:13:27)

Answer 1

There is a extra null in the data. Filter it out and map the array of objects to a 2D array and setValues the 2D array:
const data = [null,{"ID":1001,"Name":"Bob"},{"ID":1069,"Name":"Steve"},{"ID":1420,"Name":"Bill"}];
const out = data.filter(Boolean).map(Object.values);
console.log(out);
/*SetValues the entire array*/
//sheet.getRange(1,1,out.length, out[0].length).setValues(out);