private function escapeQuestionmark($query, $params) {

		preg_match_all('#([\\\]{0,})(\?)#', $query, $variables);

 		if(true === isset($variables[0])) {

 			foreach($variables[0] as $index => $variable) {

 				//Check if ? sign is escaped or not
 				if(strlen($variables[1][$index]) % 2 !== 0) {
 					continue;
 				}

 				if(false === isset($params[$index])) {
 					return trigger_error('Number of variable elements query string does not match number of bind variables');
 				}

 				$var = $params[$index];

 				switch(gettype($var)) {

					case 'string' : $var = '"' . $this -> escape($var) . '"'; break;
					case 'NULL' : $var = 'NULL'; break;
					default : $var = $this -> escape($var); break;
				}
 				
 				$query = preg_replace('#' . preg_quote($variable, '/') . '#', $var, $query, 1);
 			}
 		}

		return $query;
	}