Ubuntu 升级到 20.04 后，用户“root”@“localhost”的访问被拒绝（使用密码：是）

Question

将 Ubuntu 从 18.04 升级到 20.04 后，我无法访问我们的系统。我收到Access Denied denied for user 'root'@'localhost' (using password: yes)。我尝试使用mysql -u root -p，输入密码后我可以连接，但使用mysql -u root -h 127.0.0.1 时出现错误access denied。

补充一下，数据库中有3个root用户，如下：

+------------------+-----------------+
| user             | host            |
+------------------+-----------------+
| remote           | %               |
| root             | 127.0.0.1       |
| root             | ::1             |
| debian-sys-maint | localhost       |
| mysql.session    | localhost       |
| mysql.sys        | localhost       |
| phpmyadmin       | localhost       |
| remote           | localhost       |
| root             | localhost       |
+------------------+-----------------+

Answer 1

GRANT ALL PRIVILEGES ON *.* TO 'root'@'%' IDENTIFIED BY 'YOURPWD';