IMHO the real proper solution is to have an SQL parser, so you can have your SQL represented as an AST, do some operations on it, then compile it back to a query.

Sadly, I'm not aware of any good solutions to this. SQLAlchemy Core can build an operates on an AST, but it doesn't parse raw SQL into a query (so one has to write their queries in Python, not SQL). Some parser libraries I've seen were able to parse the query but didn't have much in terms of manipulations and compiling it back.