Linux下mysql的root密码修改方法

 $ cat /proc/version
 Linux version 4.8.3-x86_64-linode76 (maker@build) (gcc version 4.7.2 (Debian 4.7.2-5) ) #1 SMP Thu Oct 20 19:05:39 EDT 2016
 $ lsb_release -a
 No LSB modules are available.
 Distributor ID: Ubuntu
 Description: Ubuntu 16.04.1 LTS
 Release: 16.04
 Codename: xenial

 mysql> show variables like "%version%";
 +-------------------------+-------------------------+
 | Variable_name  | Value   |
 +-------------------------+-------------------------+
 | innodb_version  | 5.7.16   |
 | protocol_version | 10   |
 | slave_type_conversions |    |
 | tls_version  | TLSv1,TLSv1.1  |
 | version   | 5.7.16-0ubuntu0.16.04.1 |
 | version_comment  | (Ubuntu)  |
 | version_compile_machine | x86_64   |
 | version_compile_os | Linux   |
 +-------------------------+-------------------------+

 sudo service mysql stop

 sudo mysqld_safe --skip-grant-tables --skip-networking &

 mysql -u root

 mysql> use mysql;
 mysql> update user set authentication_string=password('password') where user='root';
 mysql> flush privileges;

 mysql > quit

 sudo service mysql restart

 mysql -u root -p

 mysql> update user set password=PASSWORD("password") where User='root';

 ERROR 1054 (42S22): Unknown column 'password' in 'field list'

 update user set authentication_string=password('password') where user='root';

ERROR 2002 (HY000): Can't connect to local MySQL server through socket '/var/run/mysqld/mysqld.sock' (2)

 ps -A|grep mysql

 sudo pkill mysql

 ps -A|grep mysqld

 sudo pkill mysqld

 service mysql restart

 mysql -u root -p