Moodle Integration Sample Sites or the way to do it
No such integration exists today so there is no sample. To implement such integration, I would recommend building an extension for CiviCRM that could interface with Moodle's APIs:

https://docs.moodle.org/dev/Core_APIs

You could also consider the opposite, creating a Moodle plugin that would interface with the CiviCRM API:

https://wiki.civicrm.org/confluence/display/CRMDOC/Using+the+API