Still don't know if you want an external or internal DSL.

External means you need an interpreter (parser + compiler) for a string holding SQL.

Internal means chaining/cascading Perl functions/methods with "SQL-like" names and semantics in combination with Perl builtins like shown before.

I prefer the latter.

> I mean SELECTs of not more than moderate complexity.

Please gimme some explicit examples of those SQLs of "moderate complexity" and I'll be pleased to show an internal DSL approach built on FP.