Related Q&A: Python Sololearn Database Access
/*
  versioned. Push required on change:
  Save.
  File|Manage versions...
  Save New Version
  Publish|Deploy as web app
  Update Project Version
  
  New services? Auth scope changes.
  Must approve additional svcs (send email, ...)
  Script Editor Run | Setup
*/
var GSP = PropertiesService.getScriptProperties();

function doGet(e) {
  return doIt(e);
}

function doPost(e) {
  return doIt(e);
}

function doIt(e) {
  var gpl=LockService.getPublicLock();
  gpl.waitLock(1250); // 1.25s
  
  try {
    var sheets=SpreadsheetApp.openById(GSP.getProperty("key"));
    var sheet=sheets.getSheetByName("sheet1");
    
    var headers=sheet.getRange(1,1,1, sheet.getLastColumn()).getValues()[0];
    var nextRow=sheet.getLastRow()+1;
    
    var row=[];
    for(i in headers){
      if(headers[i]=="timestamp"){
        row.push(new(Date));
      } else {
        row.push(e.parameter[headers[i]]);
      }
    }
    sheet.getRange(nextRow,1,1, row.length).setValues([row]);
    return ContentService
      .createTextOutput(JSON.stringify({"result":"success", "row": nextRow}))
      .setMimeType(ContentService.MimeType.JSON);
  } catch(e) {
    return ContentService
      .createTextOutput(JSON.stringify({"result":"error", "error": e}))
      .setMimeType(ContentService.MimeType.JSON);
  } finally {
    gpl.releaseLock();
  }
}

function setup() {
  var doc=SpreadsheetApp.getActiveSpreadsheet();
  GSP.setProperty("key", doc.getId());
}
persistent data app script
