Wikidata query for finding presidents - sparql

Question

I was learning the wikidata query language, and wanted to find the US president's name along with grand father, great grand father and so on...
I tried this to get a father, but how to find the father's father and so on...
SELECT ?valLabel ?resLabel
WHERE {
?val wdt:P31 wd:Q5.
?val wdt:P27 wd:Q30.
?val wdt:P106 wd:Q82955.
?val wdt:P22 wd:Q11806.
OPTIONAL { ?val wdt:P22 ?res. }
SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
}

Answer 1

Your query is looking for humans who are US citizens who are politicians and whose father is John Adams.
Instead, you want a query like this (in pseudo-SPARQL):
SELECT ?presidentLabel ?fatherLabel ?gFatherLabel ?ggFatherLabel ...
WHERE {
?president position_held president_of_the_US .
OPTIONAL{?president has_father ?father .}
OPTIONAL{?father has_father ?gFather .}
OPTIONAL{?gFather has_father ?ggFather .} ...
SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
}
Notice that the optional is necessary, as there may be no information up to the great-grandfather of a president, in which case no information about the president would be returned at all.
In Wikidata, the following should work:
SELECT
?presidentLabel
?fatherLabel
?gFatherLabel
?ggFatherLabel
WHERE {
?president wdt:P39 wd:Q11696.
OPTIONAL{?president wdt:P22 ?father}
OPTIONAL{?father wdt:P22 ?gFather}
OPTIONAL{?gFather wdt:P22 ?ggFather}
SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
}
However the query seems to time out when you look beyond the president's grandfather.
Bonus: If you want the presidents in chronological order, use this query:
SELECT ?ord ?presidentLabel ?fatherLabel ?gFatherLabel
WHERE {
?president wdt:P39 wd:Q11696 ;
p:P39 ?presidency .
?presidency ps:P39 wd:Q11696 ;
pq:P1545 ?ordString .
OPTIONAL{?president wdt:P22 ?father .}
OPTIONAL{?father wdt:P22 ?gFather .}
BIND(xsd:integer(?ordString) AS ?ord)
SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
}
ORDER BY ?ord

Answer 2

Try this query
#Father - GrandFather and so on ...
SELECT ?childLabel ?fatherLabel ?grandFatherLabel ?greatGrandFather1Label ?greatGrandFather2Label
WHERE {
?child wdt:P31 wd:Q5.
?child wdt:P27 wd:Q30.
?child wdt:P106 wd:Q82955.
?child wdt:P22 wd:Q11806.
OPTIONAL { ?child wdt:P22 ?father. }
OPTIONAL { ?father wdt:P22 ?grandFather. }
OPTIONAL { ?grandFather wdt:P22 ?greatGrandFather1. }
OPTIONAL { ?greatGrandFather1 wdt:P22 ?greatGrandFather2. }
SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],en". }
}

Answer 3

Here is a query with all fathers (and their fathers, as far back as there is data in Wikidata) of all US presidents:
SELECT ?presidentLabel ?fatherLabel
WHERE
{
?president wdt:P39 wd:Q11696;
wdt:P31 wd:Q5;
wdt:P22+ ?father .
SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
Try it!