参考自：https://www.cnblogs.com/weixuqin/p/7258000.html
brew install mongodb
如果报错：
mongodb: A full installation of Xcode.app 8.3.2 is required to compile this software.
Installing just the Command Line Tools is not sufficient.
Xcode can be installed from the App Store.
Error: An unsatisfied requirement failed this build.
说明Xcode版本过低，需要更新，如果你不想更新，可以通过使用命令：
homebrew search mongodb
查看更低版本的MongoDB，然后安装更低版本的MongoDB。
brew install mongodb@3.4
启动MongoDB服务：
brew services start mongodb@3.4
关闭MongoDB服务：
brew services stop mongodb@3.4
进入MongoDB图形化界面：
mongo
查看homebrew安装的服务情况：
brew services list
If you need to have this software first in your PATH run:
echo 'export PATH="/usr/local/opt/mongodb@3.4/bin:$PATH"' >> ~/.zshrc
To have launchd start mongodb@3.4 now and restart at login:
brew services start mongodb@3.4
Or, if you don't want/need a background service you can just run:
mongod --config /usr/local/etc/mongod.conf
**我的个人博客 **：http://blog.zd200572.com和www.zd200572.com
