Question

I’m watching some lecture’s on Functional Programming and the main ‘data structure’ so to say, but there really isn’t one in FP, is lists, so my question is: when one deals a lot with database’s and ‘lists’ of data, then is Functional Programming not superior to OOP?

Answer 1

Well, Lisp deals with lists, but the lists are heterogenous, and can well represent a tree. Other languages, like Haskell, give you structured types, named and unnamed, and – in contrast to lisp – allow for static type checking.

One thing that pure functional languages do not have is the notion of stateful variables that can be assigned. Some Lisp implementations provide such state – you get a setq opeator -, while Haskell doesn’t. Reading and writing databases, however, is all about having state – and lots of it, that’s what databases are for – and about reading from and writing into it. So, operating on a database is quite the opposite of using a functional language.

It does, however, make sense to create a database query language which expresses the DB operations in a non-imperative, but in a declarative, and hence in a functional way. That’s how SQL makes sense, and that’s also how the way LINQ is defined makes sense.

So, it makes sense to have a database language which is functional, but it’s not because of the lists.