使用游标将数据更新，陷入死循环，求解释

DELIMITER $$CREATE DEFINER=`root`@`localhost` PROCEDURE `pr_test3`()BEGIN  DECLARE p_username VARCHAR(20);  DECLARE p_email VARCHAR(20) ;    DECLARE Done INT;    #得到游标，选择老的表里面的username和emailDECLARE rs CURSOR FOR SELECT username,email FROM  user LIMIT 100;  DECLARE CONTINUE HANDLER FOR SQLSTATE '02000' SET Done = 1;    OPEN rs;FETCH NEXT FROM rs INTO p_username,p_email;  #开始遍历  REPEAT  IF NOT Done THEN  #执行需要的操作    SELECT @p_username;#插入到新的库的表  INSERT INTO NEW_DB.`USER_ACCOUNT` (USERID,`PASSWORD`,`EMAIL`,`REGTIME`,`MODTIME`) VALUES (p_username,,'123456',p_email,NOW(),NOW()); #下一条 FETCH NEXT FROM rs INTO p_username,p_email;  END IF;  UNTIL Done END REPEAT;  CLOSE rs;  END$$DELIMITER ;