For my own edification, what is the goal of SPARQL compared to normal SQL or if you live in predicate-land, Prolog or Datalog?

The semantic web tools never seemed to have their breakout moment and seem to run in parallel to "mainstream" history of relational and logic programming, but I've never really understood why.

I started thinking more deeply about how I would actually do this today and it won't be as straight forward as I initially thought. Will keep it on the radar and see if I can figure out a clean way to implement. Great suggestions!