Not strictly related by I really enjoy using SQL as a general-purpose programming language for coding challenges. Here's my n queens solution in SQL, for example: https://gist.github.com/seisvelas/952185983a625cd16e1ed4d901.... I made that because I ran out of challenges on CodeWars.

implementing algorithms in SQL really made my intuition for SQL skyrocket, to the point where no tasks in my day to day data engineering role were very challenging - at least not in terms of dealing with crazy joins and subqueries and such.

I miss SQL now days (as an appsec dev). Currently, I'm learning Hoon, which is too intuitive to really replace SQL as a language for doing toy problems while having to think wierd.