Your comment made me curious, so I looked around the website and found this.

Our dataset documents Texas death row inmates executed from 1976, when the Supreme Court reinstated the death penalty, to the present. On one level, the data is simply a part of a mundane programming book. On another, each row represents immense suffering, lives lost, and in some cases amazing redemption and acceptance. In preparing for this dataset, I was deeply moved by a number of the statements and found myself re-evaluting my position on capital punishment. I hope that as we examine the data, you too will contemplate the deeper issues at play.

Just a warning for folks who might not be in a good mental spot for seeing this in their SQL tutorial right now, or even just if it wouldn’t be to your personal tastes. It’s not your average school exercise but with morbid flavoring, the site really integrates its data. It provides a lot more information about capital punishment than you strictly need to solve the database problems. That works nicely with their intention of “Exercises should be realistic and substantial”.

Likewise, the exercises here have been designed to introduce increasingly sophisticated SQL techniques while exploring the dataset in ways that people would actually be interested in.