WordPress Show title and excerpt of child pages on Parent page

When you want to display all the child pages title and excerpt of current parent page then you can display by adding following code in your page template file

<?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( $pageChild ); ?>
<h2 class="subpagetitle"><a href="<?php echo  get_permalink($pageChild->ID); ?>" rel="bookmark" title="<?php echo $pageChild->post_title; ?>"><?php echo $pageChild->post_title; ?></a></h2>
<?php/* And if you want to get the custom field values then you can get that by */
$your_custom_field = get_post_meta($pageChild->ID, 'your_custom_field', $single = true);
the_excerpt();?>
<?php endforeach; endif; ?>

If you don’t want to display child pages on every page then you can use WordPress Conditional Tags.