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

之前的答案都没有帮助我解决这个问题，所以这里是我找到的解决方案。

相关部分:

In Ubuntu systems running MySQL 5.7 (and later versions), the root MySQL user is set to authenticate using the auth_socket plugin by default rather than with a password. This allows for some greater security and usability in many cases, but it can also complicate things when you need to allow an external program (e.g., phpMyAdmin) to access the user. In order to use a password to connect to MySQL as root, you will need to switch its authentication method from auth_socket to mysql_native_password. To do this, open up the MySQL prompt from your terminal: sudo mysql Next, check which authentication method each of your MySQL user accounts use with the following command: SELECT user,authentication_string,plugin,host FROM mysql.user; Output +------------------+-------------------------------------------+-----------------------+-----------+ | user | authentication_string | plugin | host | +------------------+-------------------------------------------+-----------------------+-----------+ | root | | auth_socket | localhost | | mysql.session | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost | | mysql.sys | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost | | debian-sys-maint | *CC744277A401A7D25BE1CA89AFF17BF607F876FF | mysql_native_password | localhost | +------------------+-------------------------------------------+-----------------------+-----------+ 4 rows in set (0.00 sec) In this example, you can see that the root user does in fact authenticate using the auth_socket plugin. To configure the root account to authenticate with a password, run the following ALTER USER command. Be sure to change password to a strong password of your choosing, and note that this command will change the root password you set in Step 2: ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY 'password'; Then, run FLUSH PRIVILEGES which tells the server to reload the grant tables and put your new changes into effect: FLUSH PRIVILEGES; Check the authentication methods employed by each of your users again to confirm that root no longer authenticates using the auth_socket plugin: SELECT user,authentication_string,plugin,host FROM mysql.user; Output +------------------+-------------------------------------------+-----------------------+-----------+ | user | authentication_string | plugin | host | +------------------+-------------------------------------------+-----------------------+-----------+ | root | *3636DACC8616D997782ADD0839F92C1571D6D78F | mysql_native_password | localhost | | mysql.session | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost | | mysql.sys | *THISISNOTAVALIDPASSWORDTHATCANBEUSEDHERE | mysql_native_password | localhost | | debian-sys-maint | *CC744277A401A7D25BE1CA89AFF17BF607F876FF | mysql_native_password | localhost | +------------------+-------------------------------------------+-----------------------+-----------+ 4 rows in set (0.00 sec) You can see in this example output that the root MySQL user now authenticates using a password. Once you confirm this on your own server, you can exit the MySQL shell: exit

如果你没有足够的特权，就会发生这种情况。

输入su，输入root密码后重试。

我这样做是为了在OS x中MySQL的初始设置中设置我的根密码。

sudo sh -c 'echo /usr/local/mysql/bin > /etc/paths.d/mysql'

关闭终端并打开一个新终端。

在Linux中，可以使用以下方法设置根密码。

sudo /usr/local/mysql/support-files/mysql.server stop
sudo mysqld_safe --skip-grant-tables

(sudo mysqld_safe——skip-grant-tables:第一次对我不起作用。但在第二次尝试时，成功了。)

然后登录MySQL:

mysql -u root

FLUSH PRIVILEGES;

现在修改密码:

ALTER USER 'root'@'localhost' IDENTIFIED BY 'newpassword';

重新启动MySQL:

sudo /usr/local/mysql/support-files/mysql.server stop
sudo /usr/local/mysql/support-files/mysql.server start

根据我的经验，如果你没有sudo，它是行不通的。所以确保你的命令是;

sudo mysql -uroot -p

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“%”。