表结构:
1 CREATE TABLE IF NOT EXISTS `user` ( 2 `user_id` int(11) NOT NULL COMMENT '主键', 3 `user_level` int(11) NOT NULL DEFAULT 0 COMMENT '等级', 4 `user_name` varchar(32) NOT NULL DEFAULT 0 COMMENT '名称', 5 `server_id` int(11) NOT NULL DEFAULT 0 COMMIT '服务器编号', 6 PRIMARY KEY (`user_id`) 7 ) ENGINE=InnoDB DEFAULT CHARSET=utf8;
示例sql：
1 UPDATE user a, 2 ( 3 SELECT a.user_id FROM user a,(SELECT user_name,count(user_id) as num FROM user GROUP BY user_name HAVING num > 1) b WHERE a.user_name = b.user_name 4 ) b 5 SET a.user_name = concat('s', server_id, '.', user_name) 6 WHERE a.user_id = b.user_id