function ConstantBasedDbConfig($name)
  {
    parent :: DbConfig($name);

    $this->driver = DB_DRIVER;
    $this->host = DB_HOST;
    $this->database = DB_NAME;
    $this->user = DB_USER;
    $this->password = DB_PASSWORD;
  }
  function IniBasedDbConfig($name)
  {
    parent :: DbConfig($name);

    $toolkit =& Limb :: toolkit();
    $ini =& $toolkit->getIni('common.ini');

    $this->driver = $ini->getOption('driver', 'DB');
    $this->host = $ini->getOption('host', 'DB');
    $this->database = $ini->getOption('database', 'DB');
    $this->user = $ini->getOption('user', 'DB');
    $this->password = $ini->getOption('password', 'DB');
  }