Show list of Child pages and Featured Image on Current Page

<?php
$child_pages = $wpdb->get_results("SELECT *    FROM $wpdb->posts WHERE post_parent = ".$post->ID."    AND post_type = 'page' ORDER BY menu_order", 'OBJECT');    ?>
<?php if ( $child_pages ) : foreach ( $child_pages as $pageChild ) : setup_postdata( $pageChild ); ?>
<div class="child-thumb">
  <?php echo get_the_post_thumbnail($pageChild->ID, 'thumbnail'); ?>
 <a href="<?php echo  get_permalink($pageChild->ID); ?>" rel="bookmark" title="<?php echo $pageChild->post_title; ?>"><?php echo $pageChild->post_title; ?></a>
</div>
<?php endforeach; endif;
?>