Throwing away what you know with every request is orthogonal to being functional. You really have to squint and turn your head sideways to think of PHP+SQL as b

Throwing away what you know with every request is orthogonal to being functional. You really have to squint and turn your head sideways to think of PHP+SQL as being functional, even though PHP is stateless. From the outside it's stateful, because well you are interacting with a DB. From within the PHP codebase, it's imperative and requires discipline and extended knowledge of any API you call to understand whether something mutates. The only time you can view it as actually stateless and somewhat functional is when you test or debug an integration from idempotent requests to responses without interleaving mutations.