SQLSTATE[HY000] [1698] Access denied for user 'root'@'localhost'

Question

I just installed Ubuntu 16.04 and installed web server on it. Everything works well, but I cannot access database. Even if I create new user and grant all privileges, I can\

Answer 1

In short, on MariaDB

1) sudo mysql -u root;
2) use mysql;
3) UPDATE mysql.user SET plugin = 'mysql_native_password', 
      Password = PASSWORD('pass1234') WHERE User = 'root';
4) FLUSH PRIVILEGES;
5) exit;