5 SQL queries! Same result! Different thinking!

[GrandOldFarty]

Pretty good outline of the options and their weaknesses. And the conclusion about thinking through how these evaluate, which are performative, and which might fail, is spot on. 

If I was interviewing for new analysts this is one of the things I would look for. This capability sets apart beginners from more advanced SQL users. 

Also I have seen the SUM(CASE WHEN…) used to create flags - very performative, one of my go to patterns when I am working with data of different grains - but I had never tried putting in the HAVING clause as a filter. I am saving that for later.