(US/western, not coastal)

I pronounce it ess que lite.

and always letter out SQL.

postgresql is the tricky one, naively there is no good way to pronounce it. so when formal I say "postgres Q L" but mostly just call it postgres

and because of the previous cases I have started slurring mysql, easily the most pronounceable one into "mys Q L"

Microsofts SQL server (which I have never actually used, and almost never talk about) is simply "S Q L server"