Comment by RaftPeople

> HAVING is different from WHERE because it filters after the aggregation, without requiring a separate query with an extra SELECT.

Personally I rarely use HAVING and instead use WHERE with subqueries for the following reasons:

1-I don't like repeating/duplicating a bunch of complex calcs, easier to just do WHERE in outer query on result

2-I typically have outer queries anyway for multiple reasons: break logic into reasonable chunks for humans, also for join+performance reasons (to give the optimizer a better chance at not getting confused)