如何增加PhpMyAdmin / mysql用户帐户的用户名长度？

ALTER TABLE t1 MODIFY col1 VARCHAR(2000);

参考：http://dev.mysql.com/doc/refman/5.1/en/alter-table.html

如果是MysqL的User表,则以root身份登录

MysqL --user=root MysqL -pPASSWORD
ALTER TABLE user MODIFY user CHAR(100);
commit;

以上不推荐

感谢您的反馈.我已经尝试了上述内容,并且可以成功更改列用户.但是,MysqL手册警告它

MysqL user names can be up to 16 characters long. Changing the maximum length is not supported. If you try to change it,for example by changing the length of the User column in the MysqL database tables,this will result in unpredictable behavior. (Altering privilege tables is not supported in any case.) Operating system user names might have a different maximum length. For example,Unix user names typically are limited to eight characters.

参见http://dev.mysql.com/doc/refman/4.1/en/user-names.html

谢谢@BoltClock提及它.