最近在家想写的东西，在MacOS上需要使用到MySQL。在MacOS下，使用brew来安装软件是最便捷。关于brew是什么，可在brew官网查看：brew官网
安装：
➜ ~ brew info mysql
mysql: stable 5.7.18 (bottled)
Open source relational database management system
......
➜ ~ brew install mysql
mysql的安装过程会显示，注，我安装的5.7.18，目录为/usr/local/Cellar/mysql/5.7.18_1：
==> /usr/local/Cellar/mysql/5.7.18_1/bin/mysqld –initialize-insecure –user=xiao –basedir=/usr/local/Cellar/mysql/5.7.18_1 –datadir=/usr/local/var/mysql –t
.....
We’ve installed your MySQL database without a root password. To secure it run:
mysql_secure_installation
这说明MySQL已安装成功，必需要使用mysql_secure_installation来初始化用户密码：
➜ ~ mysql.server start
Starting MySQL
SUCCESS!
➜ ~ mysql_secure_installation
Securing the MySQL server deployment.
Connecting to MySQL using a blank password.
......
按英文提示一步步设置password validation policy与password等。
测试，输入mysql_secure_installation设置过程的密码：
➜ ~ mysql -u root –p
Enter password:
Welcome to the MySQL monitor. Commands end with ; or \g.
Your MySQL connection id is 6
Server version: 5.7.18 Homebrew
......
新增用户xiao，密码为123456，并赋所有权限给他：
mysql>use mysql;
mysql>GRANT ALL PRIVILEGES ON *.* TO 'xiao'@'%' IDENTIFIED BY '123456' WITH GRANT OPTION;
mysql>flush privileges;
如果想设置开机启动MySQL，执行如下命令：
➜ ~ mkdir -p ~/Library/LaunchAgents
➜ ~ cp /usr/local/Cellar/mysql/5.7.18_1/homebrew.mxcl.mysql.plist ~/Library/LaunchAgents/
➜ ~ launchctl load -w ~/Library/LaunchAgents/homebrew.mxcl.mysql.plist
使用命令行来操作MySQL不方便，推荐使用Navicat MySQL/Preminum软件。软件安装包在网上搜索吧。
参考：
[1] https://dev.mysql.com/doc/refman/5.7/en/mysql-secure-installation.html