【1】sudo vim /etc/mysql/debian.cnf

显示

# Automatically generated for Debian scripts. DO NOT TOUCH!

[client]

host    = localhost

user    = debian-sys-maint

password = yXFCM3LmQ5wZlcKU

socket  = /var/run/mysqld/mysqld.sock

[mysql_upgrade]

host    = localhost

user    = debian-sys-maint

password = yXFCM3LmQ5wZlcKU

socket  = /var/run/mysqld/mysqld.sock

-------------------------------------------------------------------------------------------------------------------------------------------

【2】用debian-sys-maint进入mysql

mysql -u debian-sys-maint -p

password = yXFCM3LmQ5wZlcKU

use mysql

select * from user

select host,user,password_expired,password_last_changed,password_lifetime,account_locked from user;

【3】过滤查看用户信息，我的是因为plugin=auth_socket 问题

select host,user,plugin,authentication_string,password_last_changed,password_lifetime from user;

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

| host      | user            | plugin                | authentication_string                    |

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

| localhost | root            | auth_socket          | *DF4DD04B3437D57619CDDFDD68DF49E2FDCDB2A3 |

| localhost | mysql.session    | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |

| localhost | mysql.sys        | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |

| localhost | debian-sys-maint | mysql_native_password | *E635E132EF9AD03B99F30035D1F6ECBBFAB0F089 |

| %        | root            | mysql_native_password | *DF4DD04B3437D57619CDDFDD68DF49E2FDCDB2A3 |

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

【4】将首条root的plugin个in更新 

update user set plugin="mysql_native_password" where plugin="auth_socket";

mysql> select host,user,plugin,authentication_string from user;

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

| host      | user            | plugin                | authentication_string                    |

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

| localhost | root            | mysql_native_password | *DF4DD04B3437D57619CDDFDD68DF49E2FDCDB2A3 |

| localhost | mysql.session    | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |

| localhost | mysql.sys        | mysql_native_password | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE |

| localhost | debian-sys-maint | mysql_native_password | *E635E132EF9AD03B99F30035D1F6ECBBFAB0F089 |

| %        | root            | mysql_native_password | *DF4DD04B3437D57619CDDFDD68DF49E2FDCDB2A3 |

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

5 rows in set (0.00 sec)

[5]退出，重启，解决问题

exit

sudo service mysql restart