安装
brew install mysql@5.7 // 安装
brew link --force mysql@5.7 // 链接
brew services start mysql@5.7 // 启动服务
brew services stop mysql@5.7
brew services restart mysql@5.7
设置密码
启动之后，输入一行mysql_secure_installation
5.7.x对密码有了更严格的要求，分为LOW，MEDIUM，STRONG三个等级，对应要求如下：
LOW Length >= 8
MEDIUM Length >= 8, numeric, mixed case, and special characters
STRONG Length >= 8, numeric, mixed case, special characters and dictionary file
选low即可，要输入8位，我这里使用12345678 ，其他一路y。
启动
➜ ~ brew services start mysql@5.7
==> Successfully started `mysql@5.7` (label: homebrew.mxcl.mysql@5.7)
来源：oschina
链接：https://my.oschina.net/u/4366189/blog/3226362