我之前在 Mac上安装MySQL，brew install mysql，之后长时间没有使用，在执行mysql.server start时报一下错误：

/usr/local/Cellar/mysql/8.0.12/bin/mysqld_safe: line 674: /usr/local/var/mysql/zhangxideMacBook-Air.local.err: Permission denied
Logging to '/usr/local/var/mysql/zhangxideMacBook-Air.local.err'.
rm: /usr/local/var/mysql/zhangxideMacBook-Air.local.pid: Permission denied
2018-09-29T08:35:35.6NZ mysqld_safe Fatal error: Can't remove the pid file:
/usr/local/var/mysql/zhangxideMacBook-Air.local.pid.
Please remove the file manually and start /usr/local/Cellar/mysql/8.0.12/bin/mysqld_safe again;
mysqld daemon not started
/usr/local/Cellar/mysql/8.0.12/bin/mysqld_safe: line 144: /usr/local/var/mysql/zhangxideMacBook-Air.local.err: Permission denied

我这边出现这个问题主要是我没有权限开启mysql，解决方法 掐面添加sudo

sudo mysql.server start

执行后：

⇒  sudo mysql.server start
Password:
Starting MySQL
 SUCCESS!