Alat Google Chart dengan PHP &MySQl

Sesuai dengan dokumen , sudahkah Anda mencoba membuat referensi kolom dan data secara terpisah?

var data = new google.visualization.DataTable();
data.addColumn('string', 'Task');
data.addColumn('number', 'Hours per Day');
data.addRows([
  ['Work', 11],
  ['Eat', 2],
  ['Commute', 2],
  ['Watch TV', 2],
  ['Sleep', {v:7, f:'7.000'}]
]);

Untuk memformat ke dalam JSON yang benar untuk objek, Anda dapat mengaturnya sebagai berikut:

while($r = mysql_fetch_assoc($sth)) {
   if(!isset($google_JSON)){    
     $google_JSON = "{cols: [";    
     $column = array_keys($r);
     foreach($column as $key=>$value){
         $google_JSON_cols[]="{id: '".$key."', label: '".$value."'}";
     }    
     $google_JSON .= implode(",",$google_JSON_cols)."],rows: [";       
   }
   $google_JSON_rows[] = "{c:[{v: '".$r['id']."'}, {v: ".$r['quarters']."}, {v: ".$r['salary']."}]}";
}    
// you may need to change the above into a function that loops through rows, with $r['id'] etc, referring to the fields you want to inject..
echo $google_JSON.implode(",",$google_JSON_rows)."]}";