SQL and noSQL are two sides of the same coin (Erik Meijer, Gavin Bierman)

FTA:

"By applying a little more category theory we can show how a single abstraction, monads and monad comprehensions, can be used as a unified query language for both SQL and coSQL."

So just added to my reading list: Grust, T. 2003. Monad comprehensions: a versatile representation for queries. In The Functional Approach to Data Management, eds. P. Gray, L. Kerschberg, P. King, and A. Poulovassilis, 288-311. Springer Verlag.