I was sad to find that the author proclaimed "just write SQL" then fell into the trap of modeling his data as objects.
If you're going to model your data this way... you might as well use an ORM.
A better way is to just just write SQL (or datalog) and model our data, from DB all the way up to the application, as relations rather than objects.
Rather than re-hash, this idea has previously been discussed on HN here: https://news.ycombinator.com/item?id=34948816