Datalog generally has n-ary relations instead of binary relations like RDF. (That's not to say there aren't Datalogs restricted to binary relations. I believe the Datomic stuff is that way, but not this one).

Datalog precedes SPARQL by years... decades. Though not standardized AFAIK. But also ... honestly... SPARQL also is not nearly as elegant to my eyes as Datalog.

I'm glad to see a recent flush of interest for this stuff. Seems like there's a new Datalog article every week.

(I am not a Datalog expert, but I'm a relational-model-nerd)