Could Not get the second column picker value

Hi I am getting the second column picker, Iam assigning global variables, Iam not getting Table2 data,

var rows = db.execute('SELECT field1_Id,field1_Desc,field2_Id,field2_Desc FROM Table1, Table2 WHERE Table1.field1_Id = Table2.field2_Id');
var column1 = Ti.UI.createPickerColumn();
var column2 = Ti.UI.createPickerColumn();   
 
while (rows.isValidRow())
{
 
column1.addRow(Ti.UI.createPickerRow({
    title:rows.fieldByName('field1_Desc'),
    id:rows.fieldByName('field1_Id') 
}));
column2.addRow(Ti.UI.createPickerRow({
    title:rows.fieldByName('field2_Desc'),
    titleName:rows.fieldByName('field2_Id') 
}));
 
rows.next();
}
 
 var picker = Ti.UI.createPicker({
  top:'14%',
  borderColor:'#B6B6B4',
  visibleItems:6,
  useSpinner: true
});
picker.add([column1,column2]);
picker.selectionIndicator = true;   
self.add(picker);
 self.addEventListener("open", function(){
 
   picker.setSelectedRow(0, 0, false);
});
 
picker.addEventListener('change',function(e){
    Ti.App.filed1Id = {field1Desc:e.row.id};
    Ti.App.field2Id = {field2Desc:e.row.titleName};
     alert(Ti.App.filed1Id.field1Desc);
    alert(Ti.App.field2Id.field2Desc);
     infoBtn.title = '';
 
});

Iam getting the the first global variable called, but whereas secnd variable which is a second picker column doesnt dispaly the value. Thanks