The unexpected benefits of Hibernate Query Language (HQL)

I started using Castle ActiveRecord last week, in an effort to refactor the data access layer of a medium-size application that I have to re-write (or at least rinse, DRY and repeat until it is maintainable).

Firstly, kudos to the Castle team. For the most part, they have made the simple things simple. In case you're not familiar, Castle ActiveRecord is an API that supports the ActiveRecord data access pattern. Rather than re-invent the wheel, they use the robust (but somewhat complex and under-documented) NHibernate O/R Mapper for their data access.

Anyway, on to the subject at hand - HQL = Hibernate Query Language. I was hesitant to use this at first, because it is after all *text*. I dislike using text-sql in my applications because there is no type-safety, and that limits my ability to change the code. Nevertheless, as part of the refactoring process, I decided to leave some of the SQL there, for now.

I did not want to learn HQL. It seemed a waste - I don't need to work with multiple database flavors - just with Sql Server. But after many struggles, I eventually did learn it. And I am glad, because I quickly (ok, slowly) realized that HQL addressed my biggest pet peeve regarding normal SQL - it treats relations as first class citizens. This leads to wonderful, easy to read and write queries, almost exactly like I thought they should look (see my previous post for my thoughts on that).

HQL - if you have been avoiding it, consider taking a second look. Its much more than just a way of abstracting the database implementation. It is SQL, the way it should have been.