执行mysql -u root -p命令，此时并不知道root密码是什么。
[root@localhost bin]# mysql -u root -p
Enter password:
ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: YES)
2 详细步骤操作
Mysql 安装完成后临时密码存于 /var/log/mysqld.log文件中。获取自动生成的临时密码
[root@localhost bin]# grep "password" /var/log/mysqld.log
2016-12-26T05:36:59.714175Z 1 [Note] A temporary password is generated for root@localhost: tw=gB-DvY4CI
跳过root临时密码登录数据库修改密码
1. Stop mysql:systemctl stop mysqld
2. Set the mySQL environment option
systemctl set-environment MYSQLD_OPTS="--skip-grant-tables"
3. Start mysql usig the options you just set
systemctl start mysqld
4. Login as root
mysql -u root
5. Update the root user password with these mysql commands
mysql> UPDATE mysql.user SET authentication_string = PASSWORD('MyNewPassword') WHERE User = 'root' AND Host = 'localhost';
mysql> FLUSH PRIVILEGES;
mysql> quit
6. Stop mysql
systemctl stop mysqld
7. Unset the mySQL envitroment option so it starts normally next time
systemctl unset-environment MYSQLD_OPTS
8. Start mysql normally:
systemctl start mysqld
9. Try to login using your new password:
mysql -u root -p