WordPress删除文章函数:wp_delete_post

【描述】
删除一个文章,附件,或者页面.
当在文章或页面使用这个函数的时候，所有依赖这个文章或页面的内容也将被删除。包括评论，自定义字段，和文章与类别的关系

【使用方法】

<?php wp_delete_post( $postid, $force_delete ); ?>

【参数】

$postid
(整形)(可选) 文章 ID.
默认: 0

$force_delete
(布尔型) (可选) 是否绕过回收站箱直接删除 (在 WordPress 2.9 添加).
默认: false
返回值
混合型(mixed)
False on failure and a random wpdb object on success.

【例子】
删除文章
删除默认文章 “Hello World” 文章 ID 是 ‘1’.

<?php wp_delete_post(1); ?> 
 

【源文件】
wp_delete_post() 位于 wp-includes/post.php.

/**
 * Trashes or deletes a post or page.
 *
 * When the post and page is permanently deleted, everything that is tied to it is deleted also.
 * This includes comments, post meta fields, and terms associated with the post.
 *
 * The post or page is moved to trash instead of permanently deleted unless trash is
 * disabled, item is already in the trash, or $force_delete is true.
 *
 * @since 1.0.0
 * @uses do_action() on 'delete_post' before deletion unless post type is 'attachment'.
 * @uses do_action() on 'deleted_post' after deletion unless post type is 'attachment'.
 * @uses wp_delete_attachment() if post type is 'attachment'.
 * @uses wp_trash_post() if item should be trashed.
 *
 * @param int $postid Post ID.
 * @param bool $force_delete Whether to bypass trash and force deletion. Defaults to false.
 * @return mixed False on failure
 */
function wp_delete_post( $postid = 0, $force_delete = false ) {
 global $wpdb, $wp_rewrite;

 if ( !$post = $wpdb->get_row($wpdb->prepare("SELECT * FROM $wpdb->posts WHERE ID = %d", $postid)) )
  return $post;

 if ( !$force_delete && ( $post->post_type == 'post' || $post->post_type == 'page') && get_post_status( $postid ) != 'trash' && EMPTY_TRASH_DAYS )
   return wp_trash_post($postid);

 if ( $post->post_type == 'attachment' )
  return wp_delete_attachment( $postid, $force_delete );

 do_action('before_delete_post', $postid);

 delete_post_meta($postid,'_wp_trash_meta_status');
 delete_post_meta($postid,'_wp_trash_meta_time');

 wp_delete_object_term_relationships($postid, get_object_taxonomies($post->post_type));

 $parent_data = array( 'post_parent' => $post->post_parent );
 $parent_where = array( 'post_parent' => $postid );

 if ( 'page' == $post->post_type) {
   // if the page is defined in option page_on_front or post_for_posts,
  // adjust the corresponding options
  if ( get_option('page_on_front') == $postid ) {
   update_option('show_on_front', 'posts');
   delete_option('page_on_front');
  }
  if ( get_option('page_for_posts') == $postid ) {
   delete_option('page_for_posts');
  }

  // Point children of this page to its parent, also clean the cache of affected children
  $children_query = $wpdb->prepare("SELECT * FROM $wpdb->posts WHERE post_parent = %d AND post_type='page'", $postid);
  $children = $wpdb->get_results($children_query);

  $wpdb->update( $wpdb->posts, $parent_data, $parent_where + array( 'post_type' => 'page' ) );
 } else {
  unstick_post($postid);
 }

 // Do raw query.  wp_get_post_revisions() is filtered
 $revision_ids = $wpdb->get_col( $wpdb->prepare( "SELECT ID FROM $wpdb->posts WHERE post_parent = %d AND post_type = 'revision'", $postid ) );
 // Use wp_delete_post (via wp_delete_post_revision) again.  Ensures any meta/misplaced data gets cleaned up.
 foreach ( $revision_ids as $revision_id )
  wp_delete_post_revision( $revision_id );

 // Point all attachments to this post up one level
 $wpdb->update( $wpdb->posts, $parent_data, $parent_where + array( 'post_type' => 'attachment' ) );

 $comment_ids = $wpdb->get_col( $wpdb->prepare( "SELECT comment_ID FROM $wpdb->comments WHERE comment_post_ID = %d", $postid ));
 if ( ! empty($comment_ids) ) {
  do_action( 'delete_comment', $comment_ids );
  foreach ( $comment_ids as $comment_id )
   wp_delete_comment( $comment_id, true );
  do_action( 'deleted_comment', $comment_ids );
 }

 $post_meta_ids = $wpdb->get_col( $wpdb->prepare( "SELECT meta_id FROM $wpdb->postmeta WHERE post_id = %d ", $postid ));
 if ( !empty($post_meta_ids) ) {
  do_action( 'delete_postmeta', $post_meta_ids );
  $in_post_meta_ids = "'" . implode("', '", $post_meta_ids) . "'";
  $wpdb->query( "DELETE FROM $wpdb->postmeta WHERE meta_id IN($in_post_meta_ids)" );
  do_action( 'deleted_postmeta', $post_meta_ids );
 }

 do_action( 'delete_post', $postid );
 $wpdb->query( $wpdb->prepare( "DELETE FROM $wpdb->posts WHERE ID = %d", $postid ));
 do_action( 'deleted_post', $postid );

 if ( 'page' == $post->post_type ) {
  clean_page_cache($postid);

  foreach ( (array) $children as $child )
   clean_page_cache($child->ID);

  $wp_rewrite->flush_rules(false);
 } else {
  clean_post_cache($postid);
 }

 wp_clear_scheduled_hook('publish_future_post', array( $postid ) );

 do_action('after_delete_post', $postid);

 return $post;
}