Create Table: CREATE TABLE `fuinfo` (
  `fid` int(10) unsigned NOT NULL,
  `name` varchar(40) NOT NULL,
  `email` varchar(128) NOT NULL,
  UNIQUE KEY `email` (`email`),
  UNIQUE KEY `fid` (`fid`)
) ENGINE=MyISAM DEFAULT CHARSET=utf8

现在想要删除其中的email索引