在你的MySQL Workbench中，你可以到左边的侧边栏，在Management下选择“Users and Privileges”，在User Accounts下点击root，在右边的部分点击tab“Account Limits”增加最大查询，更新等，然后点击tab“Administrative Roles”，勾选复选框赋予该帐户访问权限。

需要检查的一件事是from-host筛选器。默认情况下可能是“localhost”。您正在尝试从远程客户端连接吗?将其更改为“%”。

打开并编辑/etc/my.cnf或/etc/mysql/my.cnf，具体取决于你的发行版。 在[mysqld]下添加skip-grant-tables 重新启动MySQL 你现在应该可以使用下面的命令MySQL -u root -p登录MySQL 运行mysql> flush特权; 设置新密码ALTER USER 'root'@'localhost' IDENTIFIED by 'NewPassword' 回到/etc/my.cnf，删除/comment skip-grant-tables 重新启动MySQL 现在你可以用新密码mysql -u root -p登录了

对于新Linux用户来说，这可能是一项艰巨的任务。让我用MySQL 8更新这个(目前可用的最新版本是8.0.12，截至2018-09-12)

Open "mysqld.cnf" configuration file at "/etc/mysql/mysql.conf.d/". Add skip-grant-tables to the next line of [mysql] text and save. Restart the MySQL service as "sudo service mysql restart". Now your MySQL is free of any authentication. Connect to the MySQL client (also known as mysql-shell) as mysql -u root -p. There is no password to be keyed in as of now. Run SQL command flush privileges; Reset the password now as ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPassword'; Now let's get back to the normal state; remove that line "skip-grant-tables" from "mysqld.cnf" and restart the service.

就是这样。

窗口:

cd \ampps\mysql\bin ：

mysql.exe -u root -pmysql

mysql启动后(可以看到shell是这样的mysql>) 使用这个查询:

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

请再次使用root访问

使用sudo修改密码:

sudo mysql

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

来源:Phoenixnap -拒绝访问用户根localhost