query-a354276e935fefc7812f3c303b0a5500

rq turtle/ttl

optional WHERE statement?Hi, using an f-String for replacement in Python, I loop through a list of historical persons trying to get their family information. Unfortunately, my query only gives me information if the person has an entry for her/his father AND an entry for her/his mother AND an entry for one or more child(ren). Since many persons do not have entries for one or the other, I don't receive any information from the Wikidata. How can I make the WHERE statements facultative/optional? I mean like "try; except: continue" . I would like to get something like an empty string, if there is no information in the database. In the example, Tilo Wilmowsky (Q2433711) does not have an entry for his mother.

Use at

• https://query.wikidata.org/sparql

PREFIX wikibase: <http://wikiba.se/ontology#>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX bd: <http://www.bigdata.com/rdf#>
SELECT ?personLabel ?motherLabel ?mother ?fatherLabel ?father ?childLabel ?child 
            WHERE { VALUES ?person { wd:Q2433711 } 
            ?person wdt:P22 ?father . 
            ?person wdt:P25 ?mother . 
            ?person wdt:P40 ?child .
            SERVICE wikibase:label { bd:serviceParam wikibase:language "[AUTO_LANGUAGE],de" }
            }

Query found at

• https://www.wikidata.org/wiki/Wikidata:Request_a_query/Archive/2021/10