title: Get Url for all videos in a YouTube playlist
body: <p>I am fresh android developer who is trying to develop an app that displays videos from a YouTube playlist and user can like it or comment it.
  I have used YouTube API to display the videos and work fine but for like and comment options I need to create a database.
  In order to create the database, I need to get the videos Id(I think is the url or URI) and I don't know how to get it.
  Secondly, which database would you recommend me in order to enable the app to be used by multiple users from different android phones in the same time.
  Please help me, I am struggling for many days to achieve this.</p>