public static function addCategory(Base_PDO $_dbh, $name)
 {
     $_dbh->query("INSERT INTO category (`subject`) VALUES (?)", array($name));
     $id = $_dbh->lastInsertId();
     self::$categories[$id] = $name;
     return intval($id);
 }
 public static function addAuthor(Base_PDO $_dbh, $name)
 {
     $_dbh->query("INSERT INTO author (name_full) VALUES (?)", array($name));
     $id = $_dbh->lastInsertId();
     self::$authors[$id] = $name;
     return intval($id);
 }