Groundhog (http://hackage.haskell.org/package/groundhog) is a nice "ORM" for Haskell. If you need something more flexible you can drop down and write raw SQL with postgresql-simple (http://hackage.haskell.org/package/postgresql-simple). There's also a corresponding mysql-simple package.

There are several HTTP clients:

http-streams (http://hackage.haskell.org/package/http-streams)

http-conduit (http://hackage.haskell.org/package/http-conduit)

wreq (http://hackage.haskell.org/package/wreq)