MYSQL：使用UPDATE修改用户名，无法登录的问题
1、创建一个用户test/test
www.2cto.com
[sql]
mysql> create user test identified by 'test';
Query OK, 0 rows affected (0.00 sec)
mysql> exit
Bye
2、使用test/test用户登录成功
[sql]
C:\Users\qxl>mysql -utest -ptest
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 25
Server version: 5.1.28-rc-community MySQL Community Server (GPL)
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> exit www.2cto.com
Bye
3、使用root用户登录，修改test用户名为newuser
[sql]
C:\Users\qxl>mysql -uroot -p
Enter password: ****
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 27
Server version: 5.1.28-rc-community MySQL Community Server (GPL)
Type 'help;' or '\h' for help. Type '\c' to clear the buffer.
mysql> update mysql.user set user='newuser' where user='test';
Query OK, 1 row affected (0.00 sec)
Rows matched: 1 Changed: 1 Warnings: 0
mysql> exit
Bye
4、使用newuser/test登录失败
[sql]
C:\Users\qxl>mysql -unewuser -ptest
ERROR 1045 (28000): Access denied for user 'newuser'@'localhost' (using password: YES)