I strongly object to such obfuscated programming. How many beginners who subscribed to this forum could be misled into thinking "wow ! clever trick I've got to find an occasion to use it".
The purpose of these brainteasers is not to confuse anyone nor to encourage folks to write code that is not clear, but to get you to fully understand HOW things work. After all, what would be the fun in always working with clear examples that don't encourage you to think?
OK, if you want to play with brainteasers. However, beginners and even intermediate SQL'ers would benefit a lot by reading topnotch articles such as the Running Count by Jeff Moden. Then you end up with considerably more useful and practical knowledge.
As I mentioned, this isn't to confuse newbies, but to give us "old hands" a bit of a noggin nuggin'!
I remember from the early 1980's the great Obfuscated C Code contest. One in particular was formatted so that the listing looked like the pi number, only it was calculating the value of e.
I remember those contests quite well and rather enjoyed them. Again, the purpose was not to encourage obfuscated coding in production use but to provide brain stimulation. Don't get so upset over it!
"...when ye are in the service of your fellow beings ye are only in the service of your God." -- Mosiah 2:17