mysql登陆问题

1.centos6下mysql5.7的登陆问题

问题的描述：ERROR 1045 (28000): Access denied for user 'root'@'localhost' (using password: NO)

解决方法：1. 关闭服务 service mysqld stop

2. --skip-grant-tables启动  mysqld_safe --user=mysql --skip-grant-tables

2016-12-16T11:11:07.958205Z mysqld_safe Logging to '/var/log/mysqld.log'.
2016-12-16T11:11:07.963470Z mysqld_safe Logging to '/var/log/mysqld.log'.
2016-12-16T11:11:08.009734Z mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql

3. 登陆命令  mysql -uroot

4. 选择数据库： use mysql

5. 修改密码和host: update user set host='%' ,authentication_string=password('root') where user='root'

6. 刷新权限：flush privileges; 注意这一步不要忘记

7. 重启服务：service mysqld restart;

8. 登陆：mysql -uroot -p root

2. mysql5.7密码重置问题

问题描述：ERROR 1820 (HY000): You must reset your password using ALTER USER statement before executing this statement.

问题解决方法：1. 设置密码：set password = password('123456');

报错：ERROR 1819 (HY000): Your password does not satisfy the current policy requirements

原因是MySQL5.6.6增加了密码强度验证插件validate_password，相关参数设置的较为严格密码的长度,

123456不符合mysql的默认密码约束， 如果一定 要用这个密码请修改相关配置，

参考：http://blog.csdn.net/zyz511919766/article/details/12752741

2.  设置密码永不过期： alter user 'root'@'%' password expire never;

3.  刷新 flush privileges;