Create a list of child pages and display their content on the parent page including the featured image

<?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; ?>