WordPress教程：如何删除文章的同时删除图片附件以及特色图像

/* 删除文章时删除图片附件
/* ———————— */
function delete_post_and_attachments($post_ID) {
global $wpdb;


//删除特色图片
$thumbnails = $wpdb->get_results("SELECT * FROM $wpdb->postmeta WHERE meta_key = '_thumbnail_id' AND post_id = $post_ID");
foreach ($thumbnails as $thumbnail) {
wp_delete_attachment($thumbnail->meta_value, true);
}


//删除图片附件
$attachments = $wpdb->get_results("SELECT * FROM $wpdb->posts WHERE post_parent = $post_ID AND post_type = 'attachment'");
foreach ($attachments as $attachment) {
wp_delete_attachment($attachment->ID, true);
}
$wpdb->query("DELETE FROM $wpdb->postmeta WHERE meta_key = '_thumbnail_id' AND post_id = $post_ID");
}
add_action('before_delete_post', 'delete_post_and_attachments');