protected function doDelete()
 {
     global $ilDB;
     $this->deleteImage();
     include_once "Modules/Blog/classes/class.ilBlogPosting.php";
     ilBlogPosting::deleteAllBlogPostings($this->id);
     // remove all notifications
     include_once "./Services/Notification/classes/class.ilNotification.php";
     ilNotification::removeForObject(ilNotification::TYPE_BLOG, $this->id);
     $ilDB->manipulate("DELETE FROM il_blog" . " WHERE id = " . $ilDB->quote($this->id, "integer"));
 }