这就是对我有效的方法:

Make sure no other MySQL process is running. To check this do the following: From the terminal, run this command: lsof -i:3306 If any PID is returned, kill it using kill -9 PID Go to System Preferences → MySQL → check if any MySQL instances are running, stop them. Start MySQL with the command: sudo /usr/local/mysql/bin/mysqld_safe --skip-grant-tables The password for every user is stored in the mysql.user table under columns User and authentication_string respectively. We can update the table as: UPDATE mysql.user SET authentication_string='your_password' where User='root'

当您登录MySQL终端时，请尝试执行FLUSH PRIVILEGES命令。如果这不起作用，请在MySQL终端中尝试以下命令集

mysql -u root

mysql> USE mysql;
mysql> UPDATE user SET password=PASSWORD("NEWPASSWORD") WHERE User='root';
mysql> FLUSH PRIVILEGES;
mysql> quit

用你想要的任何密码更改NEWPASSWORD。应该都准备好了!

更新:从MySQL 5.7开始，密码字段被重命名为authentication_string。修改密码时，使用以下查询来修改密码。所有其他命令保持不变:

mysql> UPDATE user SET authentication_string=PASSWORD("NEWPASSWORD") WHERE User='root';

请不要使用MySQL 8.0+

mysql> UPDATE mysql.user SET authentication_string='password' WHERE User='root'; 

因为它覆盖了authentication_string，它应该是一个哈希而不是纯文本，而是使用:

mysql> `ALTER USER 'root'@'localhost' IDENTIFIED BY 'MyNewPass';` 

这就是对我有效的方法:

Make sure no other MySQL process is running. To check this do the following: From the terminal, run this command: lsof -i:3306 If any PID is returned, kill it using kill -9 PID Go to System Preferences → MySQL → check if any MySQL instances are running, stop them. Start MySQL with the command: sudo /usr/local/mysql/bin/mysqld_safe --skip-grant-tables The password for every user is stored in the mysql.user table under columns User and authentication_string respectively. We can update the table as: UPDATE mysql.user SET authentication_string='your_password' where User='root'

在终端中，写入mysql -u root -p并点击Return。

输入您必须记下的当前MySQL密码。

并设置密码:

SET PASSWORD = PASSWORD('new_password');

更多细节请参考这里的文档。

MySQL 8有了很大的变化。我发现MySQL 8.0“如何重置根密码”文档的以下修改适用于Mac OS X。

创建一个临时文件$HOME/mysql.root.txt，用SQL更新根密码:

ALTER USER 'root'@'localhost' IDENTIFIED WITH mysql_native_password BY '<new-password>';

这使用mysql_native_password来避免身份验证插件'caching_sha2_password'无法加载错误，如果我省略该选项，我就会得到这个错误。

停止服务器，使用——init-file选项来设置根密码，然后重新启动服务器:

mysql.server stop
mysql.server start --init-file=$HOME/mysql.root.txt
mysql.server stop
mysql.server start

mysqld_safe --skip-grant-tables
mysql -u root
UPDATE mysql.user SET authentication_string='yourpasswd' WHERE User='root';
FLUSH PRIVILEGES;
ALTER USER 'root'@'localhost' IDENTIFIED WITH caching_sha2_password BY 'yourpasswd';

每次我的MacBook重启时，我都需要这样做。