In my case, the file did not exist. In MySQL Workbench I went to OPTIONS FILE and found some default values. I clicked apply. It asked for permission. It then created the my.cnf file under /etc. However, it is very important to keep in mind that the first time you click "apply", you do not make any changes to the default configuration. Once the file has been created, you can make changes which will be applied when you click "apply". Otherwise you will not be shown the apply button when you make changes.

我在macOS High Sierra 10.13.3版本中使用mysql 5.7.17版本，我在这里找到了mysql配置文件。

cd /usr/local/mysql/support-files/my-default.cnf

MySQL 5.7.18版本后，在support-files目录下不再提供默认配置文件。 因此，您可以在MySQL读取的位置手动创建my.cnf文件，例如/etc/mysql/my.cnf，并在该文件中添加您想要添加的配置。

在MAC OS上，一个快速的方法是:

sudo find /usr/ -type f -iname "*my.cnf*"

or

brew list mysql@5.7 |grep -i my.cnf

问候

我正在运行MacOS Catalina(10.15.3)，并在/usr/local/etc中找到my.cnf

rDefault选项按照给定的顺序从以下文件中读取: /etc/my.cnf /etc/mysql/my.cnf /usr/local/mysql/etc/my.cnf ~/.my.cnf