一，问题描述：

MysqlERROR1698(28000)解决，新装了mysql-server-5.7,登录为这一问题，普通用户不能进mysql,只有root用户才能进，并且不需要任何密码。

~$ mysql -u root -p

Enter password:

ERROR 1698 (28000): Access denied for user 'root'@'localhost'

二，解决步骤：

停止mysql服务

~$ sudo service mysql stop

以安全模式启动MySQL

~$ sudo mysqld_safe --skip-grant-tables &

MySQL启动之后就可以不用密码登陆了

~$ mysql -u root

Welcome to the MySQL monitor. Commands end with ; or g.

Your MySQL connection id is 2

Server version: 5.7.10 MySQL Community Server (GPL)

查看一下user表，错误的起因就是在这里， root的plugin被修改成了auth_socket，用密码登陆的plugin应该是mysql_native_password。

mysql> select user, plugin from mysql.user;

+-----------+-----------------------+

| user | plugin |

+-----------+-----------------------+

| root | auth_socket |

| mysql.sys | mysql_native_password |

| dev | mysql_native_password |

+-----------+-----------------------+

3 rows in set (0.01 sec)

关于auth_socket，在官方有说明： https://dev.mysql.com/doc/mysql-security-excerpt/5.5/en/socket-authentication-plugin.html ，反正现在暂时不用它， 那就把这里改了。

mysql> update mysql.user set authentication_string=PASSWORD('newPwd'), plugin='mysql_native_password' where user='root';

Query OK, 1 row affected, 1 warning (0.00 sec)

Rows matched: 1 Changed: 1 Warnings: 1

mysql> flush privileges;

Query OK, 0 rows affected (0.00 sec)

重启服务，问题就解决了

~$ sudo service mysql stop

...

* MySQL Community Server 5.7.10 is stopped

~$ sudo service mysql start

..

* MySQL Community Server 5.7.10 is started

~$ mysql -u root -p

Enter password:

Welcome to the MySQL monitor. Commands end with ; or g.

Your MySQL connection id is 2

Server version: 5.7.10 MySQL Community Server (GPL)