@ -17,7 +17,7 @@ class Db {
* @param Array $array data
* @return String string of '?' placeholders matching the number of elements in array
*/
public function buildPlaceholders($array){
public static function buildPlaceholders($array){
$count = count($array);
$placeholders = array_fill(0, $count, '?');
$stmt = implode(', ', $placeholders);