Return a nested data structure from a SPARQL query

Question

If I have a graph with this kind of structure:

@prefix  :        .
@prefix  rdf:     .
         


        

Answer 1

Both answers do not mention the danger of Cartesian explosion. If you have mulivalued fields of the root person, these will be multiplied by the multiple related persons, creating unnecessary rows. A construct may collapse those extra rows, but still: the worry should not make them in the first place. So use Union instead of straight patterns.