I cannot imagine why does this work:
select * {
<http://dbpedia.org/resource/Mahatma_Gandhi> dbpedia-owl:birthName ?name.
OPTIONAL{<http://dbpedia.org/resource/Mahatma_Gandhi> dbpedia-owl:birthDate ?birthDate}
OPTIONAL{<http://dbpedia.org/resource/Mahatma_Gandhi> dbpedia-owl:restingPlace ?restingPlace}
OPTIONAL{<http://dbpedia.org/resource/Mahatma_Gandhi> dbpedia-owl:deathDate ?deathDate}
}
and this - NOT (empty bindings):
select * {
<http://dbpedia.org/resource/Winston_Churchill> dbpedia-owl:birthName ?name.
OPTIONAL{<http://dbpedia.org/resource/Winston_Churchill> dbpedia-owl:birthDate ?birthDate}
OPTIONAL{<http://dbpedia.org/resource/Winston_Churchill> dbpedia-owl:restingPlace ?restingPlace}
OPTIONAL{<http://dbpedia.org/resource/Winston_Churchill> dbpedia-owl:deathDate ?deathDate}
}
on http://live.dbpedia.org/sparql
UPD
This answer is good but when I tried to look for Vincent_van_Gogh - same problem
dbpedia:Mahatma_Gandhi
has dbpedia-owl:birthName
and dbpprop:birthName
. On the other hand dbpedia:Winston_Churchill
has only dbpprop:birthname
(note the different capitalization).
Not sure what the right way to deal with this is.