  A significant category of NoSQL approaches is known as graph da-tabases. They
are usually represented by one property graph. We introduce a functional
approach to modelling relations and property graphs. Single-valued and
multivalued functions will be sufficient in this case. Then, a typed
{\lambda}-calculus, i.e., the language of lambda terms, will be used as a data
manipulation lan-guage. Some integration options at the query language level
are discussed.
