MySQL Error::'Access denied for user'root'@'localhost'エラー解決

ソース:https://stackoverflow.com/questions/41645309/mysql-error-access-denied-for-user-rootlocalhost
用:sudo mysql
ALTER USER ‘root’@‘localhost’ IDENTIFIED WITH mysql_native_password BY ‘root’; 解決した
インストールサービスでパスワードの設定などの指示がない場合はパスワードエラーです.解決策は以下の通りsudo vim /etc/mysql/debian.cnf mysqlファイルにアクセスして元のパスワードを表示

[client]
host     = localhost
user     = debian-sys-maint     
password = 1v5Fuo0zjy6GkSCz         
socket   = /var/run/mysqld/mysqld.sock
[mysql_upgrade]
host     = localhost
user     = debian-sys-maint
password = 1v5Fuo0zjy6GkSCz
socket   = /var/run/mysqld/mysqld.sock

デフォルトのユーザー名パスワードでログイン:mysql-u debian-sys-maint-p
原文抜粋:
Asked 3 years, 2 months ago
$ ./mysqladmin -u root -p ‘redacted’ Enter password:

mysqladmin: connect to server at 'localhost' failed error:
'Access denied for user 'root'@'localhost' (using password: YES)'

How can I fix this?
Answers

Open & Edit /etc/my.cnf o r /etc/mysql/my.cnf , depending on your distro.

Add skip-grant-tables under [mysqld]

Restart Mysql

You should be able to login to mysql now using the below command mysql -u root -p

Run mysql> flush privileges;

Set new password by ALTER USER 'root'@'localhost' IDENTIFIED BY 'NewPassword';

Go back to/etc/my.cnf and remove/comment skip-grant-tables

Restart Mysql

Now you will be able to login with the new password mysql -u root -p

All solutions I found were much more complex than necessary and none worked for me. Here is the solution that solved my problem. No need to restart mysqld or start it with special privileges.

sudo mysql

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'root';

With a single query we are changing the auth_plugin to mysql_native_password and setting the root password to root (feel free to change it in the query)
Now you should be able to login with root. More information can be found in mysql documentation
(exit mysql console with Ctrl + D or by typing exit)