/**
 * 使用CodeIgniter检查数据库连接
 *
 * @access protected
 * @param string  $protocol protocol to connect with
 * @param string  $host  host to connect to
 * @param string  $user  username to login with
 * @param string  $pass  password to login with
 * @param string  $database database to check for
 * @param integer  $port  port to connect on (optional)
 * @return bool
 * @arrange (512.笔记) jb51.cc
 **/
protected function _check_db($protocol,$host,$user,$password,$database,$port = NULL)
{
 // prep the DSN string
 $dsn = "{$protocol}://{$user}:{$password}@{$host}/{$database}";
 if($port !== NULL)
 {
  $dsn .="?port={$port}";
 }
 // Load the database and dbutil
 $this->load->database($dsn);
 $this->load->dbutil();
 // check the connection details
 $check = $this->dbutil->database_exists($database);
 // close the database
 $this->db->close();
 // return our status
 return $check;
}


/***   来自编程之家 jb51.cc（jb51.cc）   ***/