以前写的，笨办法，不知道大家有什么好的办法没有？
表结构：
/*DDL Information For - t_girl.yld1*/
-------------------------------------
Table Create Table
------ ---------------------------------------------------------
yld1 CREATE TABLE `yld1` (
`id` int(11) default NULL,
`uid` int(11) default NULL
) ENGINE=MyISAM DEFAULT CHARSET=utf8 ROW_FORMAT=DYNAMIC
初始数据：
query result(4 records)
| id | uid |
| (NULL) | 6 |
| (NULL) | 5 |
| 2 | (NULL) |
| 1 | (NULL) |
执行过程：
create table yld2 select * from yld1
delete from yld1 where id is null;
delete from yld2 where id is not null;
alter table yld1 add autoid int not null AUTO_INCREMENT primary key;
alter table yld2 add autoid int not null AUTO_INCREMENT primary key;
update yld1 as a,yld2 as b set a.uid = b.uid where a.autoid = b.autoid;
alter table yld1 drop autoid;
drop table yld2;
最终结果：
query result(2 records)
| id | uid |
| 2 | 6 |
| 1 | 5 |
