mysql的key

--
-- 表的结构 `ecs_ad`
--

CREATE TABLE IF NOT EXISTS `ecs_ad` (
  `ad_id` smallint(5) unsigned NOT NULL auto_increment,
  `position_id` smallint(5) unsigned NOT NULL default '0',
  `media_type` tinyint(3) unsigned NOT NULL default '0',
  `ad_name` varchar(60) NOT NULL default '',
  `ad_link` varchar(255) NOT NULL default '',
  `ad_code` text NOT NULL,
  `start_time` int(11) NOT NULL default '0',
  `end_time` int(11) NOT NULL default '0',
  `link_man` varchar(60) NOT NULL default '',
  `link_email` varchar(60) NOT NULL default '',
  `link_phone` varchar(60) NOT NULL default '',
  `click_count` mediumint(8) unsigned NOT NULL default '0',
  `enabled` tinyint(3) unsigned NOT NULL default '1',
  PRIMARY KEY  (`ad_id`),
  KEY `position_id` (`position_id`),
  KEY `enabled` (`enabled`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8 AUTO_INCREMENT=5 ;