Tutorial for working with relations?

Hi,

I’m trying to get my head around model relationships with phoenix and ecto and I keep running into tutorials and docs like this one (http://michaelhudson.net.au/on-getting-started-with-phoenix-v1-3-0) that get the relationships set up but don’t do anything with them. Is there perhaps a tutorial or an example app that is more complete than this?

Thank you.

The plataformatec book on ecto talks a lot about queries and relationships.
http://pages.plataformatec.com.br/ebook-whats-new-in-ecto-2-0