Home Database Mysql Tutorial [转]Access denied for user 'root'@'l_MySQL

[转]Access denied for user 'root'@'l_MySQL

Jun 01, 2016 pm 01:39 PM

bitsCN.com 转载:http://blog.csdn.net/lyflower/article/details/6137021

# mysql -uroot -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

使用网上介绍的方法修改root用户的密码:
# mysqladmin -uroot -p password 'newpassword'
Enter password:
mysqladmin: connect to server at 'localhost' failed
error: 'Access denied for user 'root'@'localhost' (using password: YES)'

现在终于被我找到了解决方法,如下(请先测试方法三,谢谢!):
方法一:
# /etc/init.d/mysql stop
# mysqld_safe --user=mysql --skip-grant-tables --skip-networking &
# mysql -u root mysql
mysql> UPDATE user SET Password=PASSWORD('newpassword') where USER='root';
mysql> FLUSH PRIVILEGES;
mysql> quit

# /etc/init.d/mysql restart
# mysql -uroot -p
Enter password:

mysql>

 

一、MySQL修改密码方法总结

首先要说明一点的是:一般情况下,修改MySQL密码是需要有mysql里的root权限的,这样一般用户是无法更改密码的,除非请求管理员帮助修改。   

  方法一   

  使用phpMyAdmin

  (图形化管理MySql数据库的工具),这是最简单的,直接用SQL语句修改mysql数据库库的user表,不过别忘了使用PASSWORD函数,插入用户用Insert命令,修改用户用Update命令,删除用Delete命令。在本节后面有数据表user字段的详细介绍。   

  方法二   

  使用mysqladmin。输入  

  mysqladmin -u root -p oldpassword newpasswd  

执行这个命令后,需要输入root的原密码,这样root的密码将改为newpasswd。同样,把命令里的root改为你的用户名,你就可以改你自己的密码了。

  当然如果你的mysqladmin连接不上mysql

  server,或者你没有办法执行mysqladmin,那么这种方法就是无效的,而且mysqladmin无法把密码清空。   

  下面的方法都在mysql提示符下使用,且必须有mysql的root权限:   

  方法三   

  mysql> INSERT INTO mysql.user (Host,User,Password) VALUES('%','system', PASSWORD('manager'));

  mysql> FLUSH PRIVILEGES   

  确切地说这是在增加一个用户,用户名为system,密码为manager。注意要使用PASSWORD函数,然后还要使用FLUSH

  PRIVILEGES来执行确认。   

  方法四   

  和方法三一样,只是使用了REPLACE语句

  mysql> REPLACE INTO mysql.user (Host,User,Password) VALUES('%','system',PASSWORD('manager'));

  mysql> FLUSH PRIVILEGES  

  方法五   

  使用SET PASSWORD语句   

  mysql> SET PASSWORD FOR system@"%" = PASSWORD('manager');   

  你也必须使用PASSWORD()函数,但是不需要使用FLUSH PRIVILEGES来执行确认。   

方法六   

  使用GRANT ... IDENTIFIED BY语句,来进行授权。   

  mysql> GRANT USAGE ON *.* TO system@"%" IDENTIFIED BY 'manager';   

  这里PASSWORD()函数是不必要的,也不需要使用FLUSH PRIVILEGES来执行确认。   

  注:PASSWORD()函数作用是为口令字加密,在程序中MySql自动解释。  

  二、MySql中访问限制的设置方法

  我们采用两种方法来设置用户。

  进入到Mysql执行目录下(通常是c:/mysql/bin)。输入mysqld-shareware.exe,输入mysql

  --user=root mysql ,不然不能添加新用户。进入到mysql>提示符下进行操作。   

  假设我们要建立一个超级用户,用户名为system,用户口令为manager。  


  方法一  

  用Grant 命令授权,输入的代码如下:

  mysql>GRANT ALL PRIVILEGES ON *.* TO system@localhost IDENTIFIED BY 'manager' WITH GRANT OPTION;   

  应显示:Query OK, 0 rows affected (0.38 sec)  

方法二   

  对用户的每一项权限进行设置:   

  mysql>INSERT INTO user

  VALUES('localhost','system',PASSWORD('manager'),'Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y','Y');

  对于3.22.34版本的MySQL,这里共14个"Y",其相应的权限如下(按字段顺序排列):   

  权限 表列名称 相应解释 使用范围

  select Select_priv 只有在真正从一个表中检索时才需要select权限 表

  insert Insert_priv 允许您把新行插入到一个存在的表中 表

  update Update_priv 允许你用新值更新现存表中行的列 表

  delete Delete_priv 允许你删除满足条件的行 表

  create Create_priv 允许你创建新的数据库和表 数据库、表或索引

  drop Drop_priv 抛弃(删除)现存的数据库和表 数据库或表

        reload Reload_priv 允许您告诉服务器再读入授权表 服务器管理

  shutdown Shutdown_priv 可能被滥用(通过终止服务器拒绝为其他用户服务) 服务器管理

  process Process_priv 允许您察看当前执行的查询的普通文本,包括设定或改变口令查询 服务器管理

  file File_priv 权限可以被滥用在服务器上读取任何可读的文件到数据库表 服务器上的文件存取

  grant Grant_priv 允许你把你自己拥有的那些权限授给其他的用户 数据库或表

  references References_priv 允许你打开和关闭记录文件 数据库或表

  index Index_priv 允许你创建或抛弃(删除)索引 表

        alter Alter_priv 允许您改变表格,可以用于通过重新命名表来推翻权限系统 表  

  如果创建用户时只有select、insert、update和delete权限,则允许用户只能在一个数据库现有的表上实施操作.

  下面就可以创建我们要用到的数据库了,我们直接输入. 例如:我们要创建数据库名为XinXiKu,可用如下代码:  

  mysql>create database XinXiKu;   

  应显示:Query OK, 1 row affected (0.00 sec)

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