<?php
/*
 * this code results in:
 *
 * array(3) {
 *   [0]=>
 *   string(5) "42601"
 *   [1]=>
 *   int(7)
 *   [2]=>
 *   string(81) "FEHLER:  Syntaxerror at »$2«
 * LINE 2:   ORDER BY $1 $2
 *                       ^"
 * }
 */

$pdo = new PDO( ... );

$sql = <<<EOF
  SELECT id FROM foo
  ORDER BY :sort :order
  OFFSET :offset
  LIMIT :limit
EOF;

$stmt = $pdo->prepare( $sql );
$stmt->bindValue( ':sort', 'id' );
$stmt->bindValue( ':order', 'ASC' );
$stmt->bindValue( ':offset', 0, PDO::PARAM_INT );
$stmt->bindValue( ':limit', 10, PDO::PARAM_INT );

if ( $stmt->execute() !== true )
{
  var_dump( $stmt->errorInfo() );
  return;
}

var_dump( $stmt->fetchAll() );
?>