Linux/Windows下修改Mysql的用户(root)的密码

一、说明
1、查看mysql版本
方法一（终端状态，未登录mysql）
#mysql -V
方法二（登录mysql状态）
mysql>select version();
2、mysql5.7版本后mysql.user表的password字段更改为authentication_string字段，即update语句中authentication_string=password("test123")，但"="号后面password不变。
例如：#update user set password=password("test123") where user='root'; 改成#update user set authentication_string=password("test123") where user='root';
3、忘记密码时Linux和Windows下修改方法不太一样
4、修改密码后记得flush privileges刷新权限。
二、实现
1、知道密码
方法一：终端状态
#mysqladmin -uroot -p password root
Enter password:

方法二：登录状态mysql>

mysql>use mysql;
mysql>update mysql.user set password = password('root') where user = 'root';
mysql>flush privileges;2、忘记密码
Windows
#net stop mysql
#cd C:\Program Files\MySQL\MySQL Server 5.5\bin
#mysqld -nt --skip-grant-tables提示
171222 17:35:42 [Warning] option 'new': boolean value 't' wasn't recognized. Set to OFF.
171222 17:35:42 [Note] --secure-file-priv is set to NULL. Operations related to importing and exporting data are disabled
171222 17:35:42 [Note] mysqld (mysqld 5.5.54) starting as process 75604 ...
则，关闭当前cmd窗口，Ctrl+R重新打开cmd
直接
#mysql
mysql>update user set password=password("test123") WHERE user='root';   
mysql>flush privileges;
#net start mysqlLinux
#service mysql stop
#mysqld_safe --skip-grant-tables &
#mysql
mysql>
mysql> use mysql;
mysql> update mysql.user set password=password("test123") where user='root';
mysql> flush privileges;
mysql> exit;三、问题（可忽略）

1、若Windows下执行命令

#mysqladmin -uroot -p password 'root'
Enter password:
提示Warning: single quotes were not trimmed line client, as you might have expected.
则参考博文：http://blog.csdn.net/justinqin/article/details/78875977
2、Windows/Linux跳过安全检查#mysqld_safe --skip-grant-tables &
提示mysqld_safe Directory '/var/run/mysqld' for UNIX socket file don't exists
参考博文：http://blog.csdn.net/z_yttt/article/details/73650495