删除无主菜单项目

function _wp_delete_orphaned_draft_menu_items() {
	global $wpdb;
	$delete_timestamp = time() - ( DAY_IN_SECONDS * EMPTY_TRASH_DAYS );

	// Delete orphaned draft menu items.
	$menu_items_to_delete = $wpdb->get_col( $wpdb->prepare( "SELECT ID FROM $wpdb->posts AS p LEFT JOIN $wpdb->postmeta AS m ON p.ID = m.post_id WHERE post_type = 'nav_menu_item' AND post_status = 'draft' AND meta_key = '_menu_item_orphaned' AND meta_value