Negation

Understanding Negation

Negation in SPARQL lets you find things that DON'T have a property or relationship. FILTER NOT EXISTS checks if a pattern doesn't match, while MINUS subtracts matching solutions. Both achieve similar results but work differently with variable bindings.

FILTER NOT EXISTS

SELECT ?person ?personLabel ?birth
WHERE {
  ?person wdt:P31 wd:Q5 ;
          wdt:P106 wd:Q82955 ;
          wdt:P569 ?birth .
  FILTER NOT EXISTS { ?person wdt:P570 ?death . }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
LIMIT 20

FILTER NOT EXISTS checks if the inner pattern does NOT match for each result. Politicians without a death date (P570) are returned. This is the most common way to find entities missing a property.

SELECT ?country ?countryLabel
WHERE {
  ?country wdt:P31 wd:Q6256 .
  FILTER NOT EXISTS { ?country wdt:P35 ?monarch . }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY ?countryLabel

This finds countries that don't have a head of state who is a monarch. The inner pattern checks for the "head of state" property (P35), and countries without it are returned.

Using MINUS

SELECT ?person ?personLabel
WHERE {
  ?person wdt:P31 wd:Q5 ;
          wdt:P106 wd:Q901 ;
          wdt:P27 wd:Q30 .
  MINUS {
    ?person wdt:P166 ?award .
    ?award wdt:P31 wd:Q7191 .
  }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
LIMIT 20

MINUS subtracts solutions that match the inner pattern. This finds American scientists, then removes those who have received a Nobel Prize (award of instance Q7191). The result is scientists who haven't won a Nobel.

Negating Specific Values

SELECT ?city ?cityLabel ?countryLabel
WHERE {
  ?city wdt:P31 wd:Q515 ;
        wdt:P1082 ?pop ;
        wdt:P17 ?country .
  FILTER(?pop > 5000000)
  FILTER NOT EXISTS { ?city wdt:P17 wd:Q30 . }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY DESC(?pop)

This combines a population filter with negation to find large cities not in the USA. The NOT EXISTS checks specifically for country = Q30 (USA), excluding only American cities while keeping cities from other countries.

Key Entities Used in Examples