发布于 2016-03-27 00:18:29 | 156 次阅读 | 评论: 0 | 来源: 网友投递
Mysql关系型数据库管理系统
MySQL是一个开放源码的小型关联式数据库管理系统,开发者为瑞典MySQL AB公司。MySQL被广泛地应用在Internet上的中小型网站中。由于其体积小、速度快、总体拥有成本低,尤其是开放源码这一特点,许多中小型网站为了降低网站总体拥有成本而选择了MySQL作为网站数据库。
一、一般忘记密码的解决办法,需要重启Mysql
1、skip-grant-tables
我们常用的方法是使用skip-grant-tables选项,mysqld server启动之后并不使用权限系统(privilege system)。用户不需要任何账号、不受任何限制的访问数据库中所有数据。为了安全起见,通常加上 skip-networking ,mysqld不侦听任何TCP/IP连接请求。操作过程如下,
1)修改my.cnf配置文件,在mysqld选项中添加skip-grant-tables和skip-networking。
2)再重启mysqld server。
3)通过sql语句修改mysql.user表中存储密码。执行flush privileges,重新启用mysql权限系统。
UPDATE mysql.USER SET Password=PASSWORD('newpwd')WHERE User='root';
FLUSH PRIVILEGES;
UPDATE mysql.user SET Password=PASSWORD('newpwd') WHERE User='root';
FLUSH PRIVILEGES;
mysqld_safe --init-file=/home/me/mysql-init &
二、不重启mysqld的方法
1、首先得有一个可以拥有修改权限的mysql数据库账号,当前的mysql实例账号(较低权限的账号,比如可以修改test数据库)或者其他相同版本实例的账号。把data/mysql目录下面的user表相关的文件复制到data/test目录下面。
[root@localhost mysql]# cp mysql/user.* test/
[root@localhost mysql]# chown mysql.mysql test/user.*
[root@localhost mysql]# mysql -utest -p12345
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 17
Server version: 5.5.25a-log Source distribution
Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql> use test
Reading table information for completion of table and column names
You can turn off this feature to get a quicker startup with -A
Database changed
mysql> update user set password=password('yayun') where user='root';
Query OK, 0 rows affected (0.00 sec)
Rows matched: 5 Changed: 0 Warnings: 0
mysql>
mv mysql/user.MYD mysql/user.MYD.bak
mv mysql/user.MYI mysql/user.MYI.bak
cp test/user.MY* mysql/
chown mysql.mysql mysql/user.*
[root@localhost mysql]# pgrep -n mysql
2184
[root@localhost mysql]#
[root@localhost mysql]# kill -SIGHUP 2184
[root@localhost mysql]# mysql -uroot -pyayun
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 20
Server version: 5.5.25a-log Source distribution
Copyright (c) 2000, 2011, Oracle and/or its affiliates. All rights reserved.
Oracle is a registered trademark of Oracle Corporation and/or its
affiliates. Other names may be trademarks of their respective
owners.
Type 'help;' or '\h' for help. Type '\c' to clear the current input statement.
mysql>