One feature I'd expect a functional programming language to have is functions as 'first class'. (e.g. can pass as input to higher order functions). But e.g. Po

One feature I'd expect a functional programming language to have is functions as 'first class'. (e.g. can pass as input to higher order functions). But e.g. PostgreSQL doesn't have functions as a datatype. https://www.postgresql.org/docs/current/datatype.html https://www.postgresql.org/docs/current/datatype.html So, uh, SQL isn't 'functional', right?