mysql ERROR 1044 (42000): Access denied for user ''@'localhost' to database

新安装的mysql密码是空的。

./mysql -u root -p
use mysql
SELECT `Host`,`User` FROM user;
UPDATE user SET `Host` = '%' WHERE `User` = 'root' LIMIT 1;
FLUSH PRIVILEGES;

GRANT ALL PRIVILEGES ON *.* TO 'mysql'@'%' IDENTIFIED BY 'test' WITH GRANT OPTION;

方法一：
1.关闭mysql
   # service mysqld stop
2.屏蔽权限
   # mysqld_safe --skip-grant-table
   屏幕出现： Starting demo from .....
3.新开起一个终端输入
   # mysql -u root mysql
   mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root';
   mysql> FLUSH PRIVILEGES;//记得要这句话，否则如果关闭先前的终端，又会出现原来的错误
   mysql> \q

 

方法二：

mysql> use mysql
ERROR 1044 (42000): Access denied for user 'root'@'localhost' to database 'mysql'
mysql> exit
Bye
[root@testtest ~]# service mysqld stop
Stopping mysqld:                      [ OK ]
[root@testtest ~]# mysqld_safe --user=mysql --skip-grant-tables --skip-networking & 

[root@testtest ~]# mysql -u root -p -hlocalhost
Enter password: 

mysql> use mysql

mysql> SELECT host,user,password,Grant_priv,Super_priv FROM mysql.user;

mysql> UPDATE mysql.user SET Grant_priv='Y', Super_priv='Y' WHERE User='root';

mysql> FLUSH PRIVILEGES;

mysql> GRANT ALL ON *.* TO 'root'@'localhost';

mysql> GRANT ALL ON *.* TO 'root'@'cn.cn.cn.cn';

mysql> GRANT ALL ON *.* TO 'root'@'245.245.245.245';

mysql> GRANT ALL ON *.* TO 'root'@'127.0.0.1';

mysql> FLUSH PRIVILEGES;

mysql> quit
Bye
[root@testtest ~]# service mysqld start 

方法三:

在my.ini的[mysqld]字段加入： 

skip-grant-tables

?

重启mysql服务，这时的mysql不需要密码即可登录数据库

然后进入mysql

?

mysql>use mysql;

mysql>update user set password=password('新密码') WHERE User='root';

mysql>flush privileges;

运行之后最后去掉my.ini中的skip-grant-tables，重启mysqld即可。

 

 

 

 

mysql> use mysql

ERROR 1044 (42000): Access denied for user 'root'@'localhost' to database 'mysql'

mysql> exit

Bye

[root@testtest ~]# service mysqld stop

Stopping mysqld:                      [ OK ]

[root@testtest ~]# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &

 

[root@testtest ~]# mysql -u root -p -hlocalhost

Enter password:

 

mysql> use mysql

 

mysql> SELECT host,user,password,Grant_priv,Super_priv FROM mysql.user;

 

mysql> UPDATE mysql.user SET Grant_priv='Y', Super_priv='Y' WHERE User='root';

 

mysql> FLUSH PRIVILEGES;

 

mysql> GRANT ALL ON *.* TO 'root'@'localhost';

 

mysql> GRANT ALL ON *.* TO 'root'@'cn.cn.cn.cn';

 

mysql> GRANT ALL ON *.* TO 'root'@'245.245.245.245';

 

mysql> GRANT ALL ON *.* TO 'root'@'127.0.0.1';

 

mysql> FLUSH PRIVILEGES;

 

 

mysql> quit

Bye

[root@testtest ~]# service mysqld start