Cheatsheets:SPARQL: Difference between revisions

Latest revision as of 09:45, 23 August 2026

Quick reference for smart people — part of our dev cheatsheets collection.

If you are new to SPARQL, see SPARQL101.

Examples featured in this cheatsheet run as-is against the public Wikidata endpoint https://query.wikidata.org/sparql. Querying another Wikibase instance is similar, but small query adjustments may be necessary depending on how each instance is set up. See the documentation for your target instance for more info.

Basic example

Natural language question:

How many dogs and cats are featured in Wikidata?

SPARQL query:

SELECT ?animal ?animalLabel (COUNT(?item) AS ?count) WHERE {
  VALUES ?animal { wd:Q144 wd:Q146 }        # dog, cat
  ?item wdt:P31 ?animal .                   # ?item is an instance of ?animal
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
GROUP BY ?animal ?animalLabel

Result as of 2026-08-19:

dog  553
cat  239

Building a query

A query is a list of triple patterns( subject predicate object). Knowing one or two elements, you can query the rest:

Question	Known parts	Pattern
"What is the population of France?"	subject France (wd:Q142) + predicate population (wdt:P1082)	`wd:Q142 wdt:P1082 ?population .`
"Which things are dogs?"	predicate instance-of (wdt:P31) + object dog (wd:Q144)	`?x wdt:P31 wd:Q144 .`
"What is known about Einstein?"	subject Einstein (wd:Q937)	`wd:Q937 ?predicate ?value .`

Query forms

Form	Returns	Use when
SELECT	table of variable bindings	you want rows of data
ASK	true/false	you only need to know whether something exists
CONSTRUCT	an RDF graph (triples)	you want the result as RDF, not a table
DESCRIBE	a graph describing the resource	you want everything known about an entity

SELECT — what is the population of France?

SELECT ?population WHERE {
  wd:Q142 wdt:P1082 ?population .
}

Result:

68605616

ASK — is there at least one dog in Wikidata?

ASK WHERE { ?x wdt:P31 wd:Q144 . }

Result:

true

CONSTRUCT — every dog as RDF (first two). Each result row becomes a triple ?x wdt:P31 wd:Q144:

CONSTRUCT { ?x wdt:P31 wd:Q144 . }
WHERE { ?x wdt:P31 wd:Q144 . } LIMIT 2

Result (visualised, N-Triples style):

Q186486  wdt:P31  wd:Q144
Q280571  wdt:P31  wd:Q144

DESCRIBE — everything known about Einstein (all triples with wd:Q937 as subject or object):

DESCRIBE wd:Q937

Result (visualised, N-Triples style, first few of thousands):

Q937  rdfs:label   "Albert Einstein"@en
Q937  wdt:P569     1879-03-14
Q937  wdt:P570     1955-04-18
Q937  wdt:P21      wd:Q6581097   # male

Solution modifiers

DISTINCT — drop duplicate rows. Einstein and Obama are both male, so the gender repeats:

Without

With DISTINCT

SELECT ?genderLabel WHERE {
  VALUES ?person { wd:Q937 wd:Q76 }
  ?person wdt:P21 ?gender .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}

Result:

male
male

SELECT DISTINCT ?genderLabel WHERE {
  VALUES ?person { wd:Q937 wd:Q76 }
  ?person wdt:P21 ?gender .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}

Result:

male

ORDER BY + LIMIT — the 3 most populous countries, sorted descending:

Without (arbitrary order)

With ORDER BY DESC + LIMIT

SELECT ?countryLabel ?population WHERE {
  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }   # China, US, India
  ?country wdt:P1082 ?population .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}

Result:

United States        340110988
China               1404890000
India               1326093247

SELECT ?countryLabel ?population WHERE {
  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
  ?country wdt:P1082 ?population .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY DESC(?population)

Result:

China               1404890000
India               1326093247
United States        340110988

LIMIT — at most n rows:

Without (all 3)

With LIMIT 2

SELECT ?countryLabel WHERE {
  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
  ?country wdt:P1082 ?population .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}

Result:

United States
China
India

SELECT ?countryLabel WHERE {
  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
  ?country wdt:P1082 ?population .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
LIMIT 2

Result:

United States
China

OFFSET — skip rows (paging). The 2nd most populous country:

With LIMIT 1 (first)

With LIMIT 1 OFFSET 1 (second)

SELECT ?countryLabel ?population WHERE {
  ?country wdt:P31 wd:Q6256 .
  ?country wdt:P1082 ?population .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY DESC(?population)
LIMIT 1

Result:

China  1404890000

SELECT ?countryLabel ?population WHERE {
  ?country wdt:P31 wd:Q6256 .
  ?country wdt:P1082 ?population .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY DESC(?population)
LIMIT 1 OFFSET 1

Result:

India  1326093247

VALUES & BIND

VALUES restricts a variable to a list; BIND computes a new variable.

SELECT ?personLabel ?birthYear WHERE {
  VALUES ?person { wd:Q937 wd:Q76 }        # Einstein, Obama
  ?person wdt:P569 ?birth .
  BIND(YEAR(?birth) AS ?birthYear)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}

Result:

Albert Einstein  1879
Barack Obama     1961

FILTER

Category	Operators / functions
comparison	= < > <= >= !=
logical	`&& \|\| !`
string	STR() CONTAINS() STRSTARTS() STRENDS() REGEX()
numeric	ABS() ROUND() FLOOR() CEIL()
date/time	YEAR() MONTH() DAY() NOW()
term tests	isIRI() isBlank() isLiteral() LANG() DATATYPE()

comparison — countries with more than 1 billion people:

SELECT ?countryLabel ?population WHERE {
  ?country wdt:P31 wd:Q6256 .
  ?country wdt:P1082 ?population .
  FILTER(?population > 1000000000)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}

Result:

China   1404890000
India   1326093247

logical (AND) — countries with 300M–500M people:

SELECT ?countryLabel ?population WHERE {
  ?country wdt:P31 wd:Q6256 .
  ?country wdt:P1082 ?population .
  FILTER(?population > 300000000 && ?population < 500000000)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}

Result:

United States  340110988

string (STRSTARTS) — countries whose English label starts with "S":

SELECT ?countryLabel WHERE {
  ?country wdt:P31 wd:Q6256 .
  ?country rdfs:label ?countryLabel .
  FILTER(LANG(?countryLabel) = "en" && STRSTARTS(?countryLabel, "S"))
}
LIMIT 3

Result:

Saint Kitts and Nevis
Somaliland
Saint Vincent and the Grenadines

numeric (ROUND) — France's population in millions, rounded:

SELECT ?millions (ROUND(?millions) AS ?rounded) WHERE {
  wd:Q142 wdt:P1082 ?population .
  BIND(?population / 1000000 AS ?millions)
}

Result:

68.605616  69

date/time (YEAR) — Einstein's birth year:

SELECT ?personLabel (YEAR(?birth) AS ?birthyear) WHERE {
  wd:Q937 wdt:P569 ?birth .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}

Result:

Albert Einstein  1879

term test (isIRI) — the values of wdt:P31 on a dog are entities (IRIs), not literals:

SELECT ?o WHERE {
  wd:Q144 wdt:P31 ?o .
  FILTER(isIRI(?o))
}

Result:

http://www.wikidata.org/entity/Q55983715
http://www.wikidata.org/entity/Q136772238

Gotcha: an unbound variable in a FILTER makes the row fail (unbound ≠ false) — guard with BOUND() or restructure with OPTIONAL.
The unbound FILTER fails silently. This returns no rows, although Einstein exists and was born in 1879:
SELECT ?personLabel WHERE {
  VALUES ?person { wd:Q937 }
  ?person rdfs:label ?personLabel .
  FILTER(LANG(?personLabel) = "en" && ?birthYear = 1879)   # ?birthYear never bound
}
Result:
(no rows — the FILTER on an unbound variable dropped Einstein)
Fix: bind the variable first, then filter:
SELECT ?personLabel WHERE {
  VALUES ?person { wd:Q937 }
  ?person wdt:P569 ?birth .
  BIND(YEAR(?birth) AS ?birthYear)
  ?person rdfs:label ?personLabel .
  FILTER(LANG(?personLabel) = "en" && ?birthYear = 1879)
}
Result:
Albert Einstein

UNION, OPTIONAL, MINUS

Keyword	Meaning
UNION	pattern A OR pattern B (the default between patterns is AND, not OR)
OPTIONAL	declare a statement optional: do not omit a result entity because it has no value for statement
MINUS	negation: search for things that do NOT satisfy a given pattern

The default between triple patterns is AND (join): the same variable must satisfy all patterns. The following query returns only dogs that also have an image:

SELECT ?itemLabel WHERE {
  ?item wdt:P31 wd:Q144 .     # ?item is a dog
  ?item wdt:P18 ?image .      # AND has an image (same ?item!)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
LIMIT 3

Result:

Laika
Hachikō
Pickles

Because the default is AND, when you would like to find something that is/has either A "or" B, you need to use UNION

Without UNION (AND)

With UNION

SELECT ?animalLabel (COUNT(?item) AS ?n) WHERE {
  ?item wdt:P31 wd:Q144 .                    # AND: ?item must be a dog
  ?item wdt:P31 wd:Q146 .                    # AND also a cat — impossible!
  BIND("dog" AS ?animalLabel)
}
GROUP BY ?animalLabel

Result:

(no rows — nothing is both a dog and a cat)

SELECT ?animalLabel (COUNT(?item) AS ?n) WHERE {
  { ?item wdt:P31 wd:Q144 . BIND("dog" AS ?animalLabel) }
  UNION
  { ?item wdt:P31 wd:Q146 . BIND("cat" AS ?animalLabel) }
}
GROUP BY ?animalLabel

Result:

dog  553
cat  239

Use OPTIONAL when you would like to find out something when data is available, but don't care if the data is missing — Einstein (died 1955) vs Obama (alive); ?deathLabel is unbound for Obama:

SELECT ?personLabel ?deathLabel WHERE {
  VALUES ?person { wd:Q937 wd:Q76 }         # Einstein, Barack Obama
  OPTIONAL { ?person wdt:P570 ?death . }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}

Result:

Albert Einstein  1955-04-18
Barack Obama     (unbound)

If you do not declare OPTIONAL, Barack Obama will not appear in the results, as there is logically no date of death on his record.

Use MINUS when you would like to find out about things that are/have NOT something

E.g., non-French Nobel laureates:

SELECT ?personLabel WHERE {
  ?person wdt:P166 wd:Q7191 .
  MINUS { ?person wdt:P27 wd:Q142 . }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
LIMIT 3

Result:

Nobel Prize winner
Adam Bernau
Santiago Carril

Gotcha: FILTER NOT EXISTS and MINUS usually give the same result, but differ when a variable is unbound — prefer MINUS for set-difference semantics.
Both express "non-French Nobel laureates"; the results are identical:
# FILTER NOT EXISTS
SELECT ?personLabel WHERE {
  ?person wdt:P166 wd:Q7191 .
  FILTER NOT EXISTS { ?person wdt:P27 wd:Q142 . }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
LIMIT 3
# MINUS
SELECT ?personLabel WHERE {
  ?person wdt:P166 wd:Q7191 .
  MINUS { ?person wdt:P27 wd:Q142 . }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
LIMIT 3
Result (both):
Nobel Prize winner
Adam Bernau
Santiago Carril
The difference appears only when a variable inside the negated pattern is unbound: FILTER NOT EXISTS tests per-row (an unbound variable never matches), while MINUS subtracts whole patterns regardless of unbound variables.

Property paths

Path	Meaning
wdt:P279/wdt:P279	two hops (sequence)
wdt:P279+	one or more hops
wdt:P279*	zero or more hops (transitive)
wdt:P279?	zero or one hop
wdt:P31	either property
^wdt:P279	inverse direction
!wdt:P279	any property except P279

A path chains several properties into one pattern. The dog example uses subclass of (wdt:P279). Compare the direct pattern with the transitive (* = zero or more hops):

Pattern	What it matches	Live example	Returns
`?x wdt:P279 wd:Q144`	classes that are a direct kind of dog (one hop)	`?x wdt:P279 wd:Q144`	Rottweiler, Swedish Vallhund — 314
`?x wdt:P279* wd:Q144`	classes that are dog or any kind-of-kind-of-dog (any number of hops)	`?x wdt:P279* wd:Q144`	adds sub-breeds like Norman Hound → scent hound → dog — 511

The * finds things several hops away that a single triple cannot:

SELECT ?thing ?thingLabel WHERE {
  ?thing wdt:P279* wd:Q144 .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
LIMIT 3

Result:

Lapponian Herder
autism assistance dog
diabetic alert dog

(These are sub-subclasses: Lapponian Herder → herding dog → dog.)

Gotcha: a variable that appears only inside a path is not bound, so it cannot be selected.
A two-hop path (wdt:P279/wdt:P279) finds dogs two levels down (bloodhound, beagle) — but the intermediate hop is anonymous, so there is nothing to select for it:
# Path form: intermediate hop is anonymous — ?mid is not available
SELECT ?xLabel WHERE {
  ?x wdt:P279/wdt:P279 wd:Q144 .
  ?x rdfs:label ?xLabel . FILTER(LANG(?xLabel) = "en")
}
LIMIT 3
Result:
bloodhound
beagle
Chesapeake Bay Retriever
To select the intermediate value, write two explicit triples with a variable:
# Explicit form: ?mid is selectable
SELECT ?xLabel ?midLabel WHERE {
  ?x wdt:P279 ?mid .
  ?mid wdt:P279 wd:Q144 .
  ?x rdfs:label ?xLabel . FILTER(LANG(?xLabel) = "en")
  ?mid rdfs:label ?midLabel . FILTER(LANG(?midLabel) = "en")
}
LIMIT 3
Result:
shepherd dog        pastoral dog
livestock guardian dog   pastoral dog
Canadian Eskimo Dog      inuit sledge dog

Aggregates

Aggregates collapse many rows into one per group. All examples use the same three countries (China, US, India).

COUNT — how many values (the running example counts instances per animal; here: values of wdt:P1082 for the three countries):

SELECT (COUNT(?population) AS ?n) WHERE {
  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
  ?country wdt:P1082 ?population .
}

Result:

SUM — combined population of the three:

SELECT (SUM(?population) AS ?total) WHERE {
  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
  ?country wdt:P1082 ?population .
}

Result:

3071094235

AVG — mean population of the three:

SELECT (AVG(?population) AS ?avg) WHERE {
  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
  ?country wdt:P1082 ?population .
}

Result:

1023698078.33

MIN / MAX — smallest and largest of the three:

SELECT (MIN(?population) AS ?min) (MAX(?population) AS ?max) WHERE {
  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
  ?country wdt:P1082 ?population .
}

Result:

340110988  1404890000

SAMPLE — one arbitrary value (useful to squash duplicates):

SELECT (SAMPLE(?countryLabel) AS ?anyCountry) WHERE {
  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
  ?country wdt:P1082 ?population .
  ?country rdfs:label ?countryLabel .
  FILTER(LANG(?countryLabel) = "en")
}

Result:

United States

GROUP_CONCAT — Einstein's awards in one cell:

SELECT ?personLabel (GROUP_CONCAT(?awardLabel; SEPARATOR=", ") AS ?awards) WHERE {
  VALUES ?person { wd:Q937 }
  ?person wdt:P166 ?award .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
GROUP BY ?personLabel

Result:

Albert Einstein  Nobel Prize in Physics, …

GROUP BY + HAVING — the running example, filtered to groups with more than 400 instances:

SELECT ?animalLabel (COUNT(?item) AS ?n) WHERE {
  VALUES ?animal { wd:Q144 wd:Q146 }
  ?item wdt:P31 ?animal .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
GROUP BY ?animal ?animalLabel
HAVING (COUNT(?item) > 400)

Result:

dog  553

Gotcha: aggregates need GROUP BY for every non-aggregated variable. Forgetting one is a query error, not a wrong result.
Missing GROUP BY for ?animalLabel:
SELECT ?animalLabel (COUNT(?item) AS ?n) WHERE {
  VALUES ?animal { wd:Q144 wd:Q146 }
  ?item wdt:P31 ?animal .
  ?animal rdfs:label ?animalLabel .
  FILTER(LANG(?animalLabel) = "en")
}
Result:
ERROR: Bad aggregate — every non-aggregated variable needs GROUP BY

Subqueries

A query inside a query — useful for "the X with the max Y" patterns.

The most populous country, computed via a subquery:

SELECT ?countryLabel ?max WHERE {
  {
    SELECT (MAX(?population) AS ?max) WHERE {
      ?c wdt:P31 wd:Q6256 .
      ?c wdt:P1082 ?population .
    }
  }
  ?country wdt:P31 wd:Q6256 .
  ?country wdt:P1082 ?max .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}

Result:

China  1404890000

SERVICE (labels, federation)

The label service turns entity IDs into human-readable labels — used in most queries above:

SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
# then reference ?xLabel for every ?x in the query

# Federating to another endpoint (needs the remote's own IRIs, e.g. via owl:sameAs)
SELECT ?cityLabel WHERE {
  wd:Q64 wdt:P36 ?city .
  ?city owl:sameAs ?dbpediaCity .
  SERVICE <https://dbpedia.org/sparql> {
    ?dbpediaCity rdfs:label ?cityLabel .
    FILTER(LANG(?cityLabel) = "en")
  }
}

Cheatsheets:SPARQL: Difference between revisions

SeedBot (talk | contribs)

Latest revision as of 09:45, 23 August 2026

Contents

Basic example

Building a query

Query forms

Solution modifiers

VALUES & BIND

FILTER

UNION, OPTIONAL, MINUS

Property paths

Aggregates

Subqueries

SERVICE (labels, federation)

Further reading

Navigation menu

@@ Line 1: / Line 1: @@
 {{Cheatsheet}}
-SPARQL 1.1 quick syntax reference — for people who already know what SPARQL is
+If you are new to SPARQL, see [[FOSS:SPARQL|SPARQL101]].
-and need reminders on syntax. For a proper tutorial, take the
-[https://www.wikidata.org/wiki/Wikidata:SPARQL_tutorial Wikidata SPARQL tutorial]
+<blockquote>
-(works against any Wikibase endpoint). For querying a specific Wikibase
+Examples featured in this cheatsheet run as-is against the public Wikidata endpoint <syntaxhighlight lang="text" inline>https://query.wikidata.org/sparql</syntaxhighlight>. Querying another Wikibase instance is similar, but small query adjustments may be necessary depending on how each instance is set up. See the documentation for your target instance for more info.
-instance (endpoint, prefixes, label service), see [[Help:Contributing/query]].
+</blockquote>
+== Basic example ==
+Natural language question:
+<syntaxhighlight lang="text" copy>
+How many dogs and cats are featured in Wikidata?
+</syntaxhighlight>
+SPARQL query:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?animal ?animalLabel (COUNT(?item) AS ?count) WHERE {
+  VALUES ?animal { wd:Q144 wd:Q146 }        # dog, cat
+  ?item wdt:P31 ?animal .                   # ?item is an instance of ?animal
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+GROUP BY ?animal ?animalLabel
+</syntaxhighlight>
+Result as of 2026-08-19:
+<syntaxhighlight lang="text" copy>
+dog  553
+cat  239
+</syntaxhighlight>
+== Building a query ==
+A query is a list of '''triple patterns'''(
+<syntaxhighlight lang="sparql" inline>subject predicate object</syntaxhighlight>).
+Knowing one or two elements, you can query the rest:
+{| class="wikitable"
+! Question !! Known parts !! Pattern
+|-
+| "What is the population of France?" || subject France (wd:Q142) + predicate population (wdt:P1082) || <syntaxhighlight lang="sparql" inline>wd:Q142 wdt:P1082 ?population .</syntaxhighlight>
+|-
+| "Which things are dogs?" || predicate instance-of (wdt:P31) + object dog (wd:Q144) || <syntaxhighlight lang="sparql" inline>?x wdt:P31 wd:Q144 .</syntaxhighlight>
+|-
+| "What is known about Einstein?" || subject Einstein (wd:Q937) || <syntaxhighlight lang="sparql" inline>wd:Q937 ?predicate ?value .</syntaxhighlight>
+|}
 == Query forms ==
 {| class="wikitable"
-! Form !! Returns !! Example
+! Form !! Returns !! Use when
 |-
-| SELECT || table of variable bindings || <syntaxhighlight lang="sparql" inline>SELECT ?s ?p ?o WHERE { ?s ?p ?o }</syntaxhighlight>
+| SELECT || table of variable bindings || you want rows of data
 |-
-| ASK || boolean — does the pattern match? || <syntaxhighlight lang="sparql" inline>ASK WHERE { ?s ?p ?o }</syntaxhighlight>
+| ASK || true/false || you only need to know whether something exists
 |-
-| CONSTRUCT || an RDF graph || <syntaxhighlight lang="sparql" inline>CONSTRUCT { ?s ?p ?o } WHERE { ?s ?p ?o }</syntaxhighlight>
+| CONSTRUCT || an RDF graph (triples) || you want the result as RDF, not a table
 |-
-| DESCRIBE || a graph describing the resource || <syntaxhighlight lang="sparql" inline>DESCRIBE ?s WHERE { ?s ?p ?o }</syntaxhighlight>
+| DESCRIBE || a graph describing the resource || you want everything known about an entity
 |}
-== Prefixes & triple patterns ==
+'''SELECT''' — what is the population of France?
+<syntaxhighlight lang="sparql" copy>
+SELECT ?population WHERE {
+  wd:Q142 wdt:P1082 ?population .
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+68605616
+</syntaxhighlight>
+'''ASK''' — is there at least one dog in Wikidata?
+<syntaxhighlight lang="sparql" copy>
+ASK WHERE { ?x wdt:P31 wd:Q144 . }
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+true
+</syntaxhighlight>
+'''CONSTRUCT''' — every dog as RDF (first two). Each result row becomes a
+triple <syntaxhighlight lang="sparql" inline>?x wdt:P31 wd:Q144</syntaxhighlight>:
+<syntaxhighlight lang="sparql" copy>
+CONSTRUCT { ?x wdt:P31 wd:Q144 . }
+WHERE { ?x wdt:P31 wd:Q144 . } LIMIT 2
+</syntaxhighlight>
+Result (visualised, N-Triples style):
+<syntaxhighlight lang="text" copy>
+Q186486  wdt:P31  wd:Q144
+Q280571  wdt:P31  wd:Q144
+</syntaxhighlight>
-Prefixes abbreviate IRIs; the binding is endpoint-defined.
+'''DESCRIBE''' — everything known about Einstein (all triples with wd:Q937 as
+subject or object):
-<syntaxhighlight lang="sparql">
+<syntaxhighlight lang="sparql" copy>
-PREFIX ex: <http://example.org/>
+DESCRIBE wd:Q937
-SELECT ?s ?p ?o WHERE {
-  ?s ?p ?o .                    # triple pattern: subject predicate object
-  FILTER(?p = ex:age)           # constraint on a variable
-}
 </syntaxhighlight>
-Anonymous/blank node as subject or object: <syntaxhighlight lang="sparql" inline>[] ex:age 42</syntaxhighlight>.
+Result (visualised, N-Triples style, first few of thousands):
-Literals can carry datatypes or language tags:
+<syntaxhighlight lang="text" copy>
-<syntaxhighlight lang="sparql" inline>"text"^^xsd:string</syntaxhighlight>,
+Q937  rdfs:label   "Albert Einstein"@en
-<syntaxhighlight lang="sparql" inline>"café"@fr</syntaxhighlight>.
+Q937  wdt:P569     1879-03-14
+Q937  wdt:P570     1955-04-18
+Q937  wdt:P21      wd:Q6581097   # male
+</syntaxhighlight>
 == Solution modifiers ==
+'''DISTINCT''' — drop duplicate rows. Einstein and Obama are both male, so the
+gender repeats:
 {| class="wikitable"
-! Clause !! Effect
+! Without !! With DISTINCT
 |-
-| DISTINCT || drop duplicate solution rows
+|
+<syntaxhighlight lang="sparql" copy>
+SELECT ?genderLabel WHERE {
+  VALUES ?person { wd:Q937 wd:Q76 }
+  ?person wdt:P21 ?gender .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+male
+male
+</syntaxhighlight>
+||
+<syntaxhighlight lang="sparql" line highlight="1" copy>
+SELECT DISTINCT ?genderLabel WHERE {
+  VALUES ?person { wd:Q937 wd:Q76 }
+  ?person wdt:P21 ?gender .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+male
+</syntaxhighlight>
+|}
+'''ORDER BY + LIMIT''' — the 3 most populous countries, sorted descending:
+{| class="wikitable"
+! Without (arbitrary order) !! With ORDER BY DESC + LIMIT
 |-
-| ORDER BY || sort: <syntaxhighlight lang="sparql" inline>ORDER BY ASC(?x) DESC(?y)</syntaxhighlight>
+|
+<syntaxhighlight lang="sparql" copy>
+SELECT ?countryLabel ?population WHERE {
+  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }   # China, US, India
+  ?country wdt:P1082 ?population .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+United States        340110988
+China               1404890000
+India               1326093247
+</syntaxhighlight>
+||
+<syntaxhighlight lang="sparql" line highlight="6" copy>
+SELECT ?countryLabel ?population WHERE {
+  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
+  ?country wdt:P1082 ?population .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+ORDER BY DESC(?population)
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+China               1404890000
+India               1326093247
+United States        340110988
+</syntaxhighlight>
+|}
+'''LIMIT''' — at most n rows:
+{| class="wikitable"
+! Without (all 3) !! With LIMIT 2
 |-
-| LIMIT n / OFFSET n || page through results
+|
+<syntaxhighlight lang="sparql" copy>
+SELECT ?countryLabel WHERE {
+  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
+  ?country wdt:P1082 ?population .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+United States
+China
+India
+</syntaxhighlight>
+||
+<syntaxhighlight lang="sparql" line highlight="6" copy>
+SELECT ?countryLabel WHERE {
+  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
+  ?country wdt:P1082 ?population .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+LIMIT 2
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+United States
+China
+</syntaxhighlight>
+|}
+'''OFFSET''' — skip rows (paging). The 2nd most populous country:
+{| class="wikitable"
+! With LIMIT 1 (first) !! With LIMIT 1 OFFSET 1 (second)
 |-
-| GROUP BY || group rows for aggregation (see below)
+|
-|-
+<syntaxhighlight lang="sparql" copy>
-| HAVING || filter groups, like WHERE for aggregates
+SELECT ?countryLabel ?population WHERE {
+  ?country wdt:P31 wd:Q6256 .
+  ?country wdt:P1082 ?population .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+ORDER BY DESC(?population)
+LIMIT 1
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+China  1404890000
+</syntaxhighlight>
+||
+<syntaxhighlight lang="sparql" line highlight="7" copy>
+SELECT ?countryLabel ?population WHERE {
+  ?country wdt:P31 wd:Q6256 .
+  ?country wdt:P1082 ?population .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+ORDER BY DESC(?population)
+LIMIT 1 OFFSET 1
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+India  1326093247
+</syntaxhighlight>
 |}
-== FILTER expressions ==
+== VALUES & BIND ==
+VALUES restricts a variable to a list; BIND computes a new variable.
+<syntaxhighlight lang="sparql" copy>
+SELECT ?personLabel ?birthYear WHERE {
+  VALUES ?person { wd:Q937 wd:Q76 }        # Einstein, Obama
+  ?person wdt:P569 ?birth .
+  BIND(YEAR(?birth) AS ?birthYear)
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+Albert Einstein  1879
+Barack Obama     1961
+</syntaxhighlight>
+== FILTER ==
 {| class="wikitable"
-! Category !! Examples
+! Category !! Operators / functions
 |-
-| comparison || <syntaxhighlight lang="sparql" inline>= < > <= >= !=</syntaxhighlight>
+| comparison || = < > <= >= !=
 |-
 | logical || <syntaxhighlight lang="sparql" inline>&& || !</syntaxhighlight>
 |-
-| string || <syntaxhighlight lang="sparql" inline>STR() CONTAINS() STRSTARTS() STRENDS() REGEX()</syntaxhighlight>
+| string || STR() CONTAINS() STRSTARTS() STRENDS() REGEX()
+|-
+| numeric || ABS() ROUND() FLOOR() CEIL()
+|-
+| date/time || YEAR() MONTH() DAY() NOW()
+|-
+| term tests || isIRI() isBlank() isLiteral() LANG() DATATYPE()
+|}
+'''comparison''' — countries with more than 1 billion people:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?countryLabel ?population WHERE {
+  ?country wdt:P31 wd:Q6256 .
+  ?country wdt:P1082 ?population .
+  FILTER(?population > 1000000000)
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+China   1404890000
+India   1326093247
+</syntaxhighlight>
+'''logical (AND)''' — countries with 300M–500M people:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?countryLabel ?population WHERE {
+  ?country wdt:P31 wd:Q6256 .
+  ?country wdt:P1082 ?population .
+  FILTER(?population > 300000000 && ?population < 500000000)
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+United States  340110988
+</syntaxhighlight>
+'''string (STRSTARTS)''' — countries whose English label starts with "S":
+<syntaxhighlight lang="sparql" copy>
+SELECT ?countryLabel WHERE {
+  ?country wdt:P31 wd:Q6256 .
+  ?country rdfs:label ?countryLabel .
+  FILTER(LANG(?countryLabel) = "en" && STRSTARTS(?countryLabel, "S"))
+}
+LIMIT 3
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+Saint Kitts and Nevis
+Somaliland
+Saint Vincent and the Grenadines
+</syntaxhighlight>
+'''numeric (ROUND)''' — France's population in millions, rounded:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?millions (ROUND(?millions) AS ?rounded) WHERE {
+  wd:Q142 wdt:P1082 ?population .
+  BIND(?population / 1000000 AS ?millions)
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+.605616  69
+</syntaxhighlight>
+'''date/time (YEAR)''' — Einstein's birth year:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?personLabel (YEAR(?birth) AS ?birthyear) WHERE {
+  wd:Q937 wdt:P569 ?birth .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+Albert Einstein  1879
+</syntaxhighlight>
+'''term test (isIRI)''' — the values of <syntaxhighlight lang="sparql" inline>wdt:P31</syntaxhighlight> on a dog
+are entities (IRIs), not literals:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?o WHERE {
+  wd:Q144 wdt:P31 ?o .
+  FILTER(isIRI(?o))
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+http://www.wikidata.org/entity/Q55983715
+http://www.wikidata.org/entity/Q136772238
+</syntaxhighlight>
+<blockquote>'''Gotcha:''' an unbound variable in a FILTER makes the row fail (unbound ≠ false) — guard with <syntaxhighlight lang="sparql" inline>BOUND()</syntaxhighlight> or restructure with OPTIONAL.
+The unbound FILTER fails silently. This returns '''no rows''', although
+Einstein exists and was born in 1879:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?personLabel WHERE {
+  VALUES ?person { wd:Q937 }
+  ?person rdfs:label ?personLabel .
+  FILTER(LANG(?personLabel) = "en" && ?birthYear = 1879)   # ?birthYear never bound
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+(no rows — the FILTER on an unbound variable dropped Einstein)
+</syntaxhighlight>
+Fix: bind the variable first, then filter:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?personLabel WHERE {
+  VALUES ?person { wd:Q937 }
+  ?person wdt:P569 ?birth .
+  BIND(YEAR(?birth) AS ?birthYear)
+  ?person rdfs:label ?personLabel .
+  FILTER(LANG(?personLabel) = "en" && ?birthYear = 1879)
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+Albert Einstein
+</syntaxhighlight>
+</blockquote>
+== UNION, OPTIONAL, MINUS ==
+{| class="wikitable"
+! Keyword !! Meaning
+|-
+| UNION || pattern A '''OR''' pattern B (the default between patterns is AND, not OR)
 |-
-| numeric || <syntaxhighlight lang="sparql" inline>ABS() ROUND() FLOOR() CEIL() RAND()</syntaxhighlight>
+| OPTIONAL || declare a statement optional: do not omit a result entity because it has no value for statement
 |-
-| date/time || <syntaxhighlight lang="sparql" inline>YEAR() MONTH() DAY() NOW()</syntaxhighlight>
+| MINUS || negation: search for things that do '''NOT''' satisfy a given pattern
+|}
+The default between triple patterns is '''AND (join)''': the same variable must
+satisfy all patterns. The following query returns only dogs that also have an image:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?itemLabel WHERE {
+  ?item wdt:P31 wd:Q144 .     # ?item is a dog
+  ?item wdt:P18 ?image .      # AND has an image (same ?item!)
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+LIMIT 3
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+Laika
+Hachikō
+Pickles
+</syntaxhighlight>
+Because the default is AND, when you would like to find something that is/has either A "or" B, you need to use '''UNION'''
+{| class="wikitable"
+! Without UNION (AND) !! With UNION
 |-
-| terms || <syntaxhighlight lang="sparql" inline>isIRI() isBlank() isLiteral() LANG() DATATYPE()</syntaxhighlight>
+|
+<syntaxhighlight lang="sparql" copy>
+SELECT ?animalLabel (COUNT(?item) AS ?n) WHERE {
+  ?item wdt:P31 wd:Q144 .                    # AND: ?item must be a dog
+  ?item wdt:P31 wd:Q146 .                    # AND also a cat — impossible!
+  BIND("dog" AS ?animalLabel)
+}
+GROUP BY ?animalLabel
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+(no rows — nothing is both a dog and a cat)
+</syntaxhighlight>
+||
+<syntaxhighlight lang="sparql" copy>
+SELECT ?animalLabel (COUNT(?item) AS ?n) WHERE {
+  { ?item wdt:P31 wd:Q144 . BIND("dog" AS ?animalLabel) }
+  UNION
+  { ?item wdt:P31 wd:Q146 . BIND("cat" AS ?animalLabel) }
+}
+GROUP BY ?animalLabel
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+dog  553
+cat  239
+</syntaxhighlight>
 |}
-<syntaxhighlight lang="sparql">
+Use '''OPTIONAL''' when you would like to find out something when data is available, but don't care if the data is missing — Einstein (died 1955) vs Obama (alive); ?deathLabel is unbound
-FILTER(CONTAINS(STR(?label), "cat"))
+for Obama:
-FILTER(LANG(?label) = "fr")
+<syntaxhighlight lang="sparql" copy>
+SELECT ?personLabel ?deathLabel WHERE {
+  VALUES ?person { wd:Q937 wd:Q76 }         # Einstein, Barack Obama
+  OPTIONAL { ?person wdt:P570 ?death . }
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
 </syntaxhighlight>
-== VALUES & BIND ==
+Result:
+<syntaxhighlight lang="text" copy>
+Albert Einstein  1955-04-18
+Barack Obama     (unbound)
+</syntaxhighlight>
+If you do not declare '''OPTIONAL''', Barack Obama will not appear in the results, as there is logically no date of death on his record.
+Use '''MINUS''' when you would like to find out about things that are/have NOT something
+E.g., '''non-French''' Nobel laureates:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?personLabel WHERE {
+  ?person wdt:P166 wd:Q7191 .
+  MINUS { ?person wdt:P27 wd:Q142 . }
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+LIMIT 3
+</syntaxhighlight>
-<syntaxhighlight lang="sparql">
+Result:
-VALUES ?p { ex:age ex:name }        # restrict variable to a list
+<syntaxhighlight lang="text" copy>
-BIND(?a + ?b AS ?sum)               # compute and bind a new variable
+Nobel Prize winner
+Adam Bernau
+Santiago Carril
 </syntaxhighlight>
-== OPTIONAL, UNION, MINUS ==
+<blockquote>'''Gotcha:''' <syntaxhighlight lang="sparql" inline>FILTER NOT EXISTS</syntaxhighlight> and <syntaxhighlight lang="sparql" inline>MINUS</syntaxhighlight> usually give the same result, but differ when a variable is unbound — prefer MINUS for set-difference semantics.
+Both express "non-French Nobel laureates"; the results are identical:
-<syntaxhighlight lang="sparql">
+<syntaxhighlight lang="sparql" copy>
-?s ex:name ?n .
+# FILTER NOT EXISTS
-OPTIONAL { ?s ex:age ?a }           # left join — ?a missing when absent
+SELECT ?personLabel WHERE {
-{ ?s ex:age ?a } UNION { ?s ex:name ?n }   # union of two patterns
+  ?person wdt:P166 wd:Q7191 .
-?s ?p ?o .
+  FILTER NOT EXISTS { ?person wdt:P27 wd:Q142 . }
-MINUS { ?s ex:age 42 }              # remove matches
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+LIMIT 3
 </syntaxhighlight>
-Gotcha: <syntaxhighlight lang="sparql" inline>FILTER NOT EXISTS</syntaxhighlight> vs
+<syntaxhighlight lang="sparql" copy>
-<syntaxhighlight lang="sparql" inline>MINUS</syntaxhighlight> differ when a variable is
+# MINUS
-unbound — prefer <syntaxhighlight lang="sparql" inline>MINUS</syntaxhighlight> for
+SELECT ?personLabel WHERE {
-set-difference semantics.
+  ?person wdt:P166 wd:Q7191 .
+  MINUS { ?person wdt:P27 wd:Q142 . }
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+LIMIT 3
+</syntaxhighlight>
+Result (both):
+<syntaxhighlight lang="text" copy>
+Nobel Prize winner
+Adam Bernau
+Santiago Carril
+</syntaxhighlight>
+The difference appears only when a variable inside the negated pattern is
+unbound: FILTER NOT EXISTS tests per-row (an unbound variable never matches),
+while MINUS subtracts whole patterns regardless of unbound variables.
+</blockquote>
 == Property paths ==
@@ Line 104: / Line 580: @@
 ! Path !! Meaning
 |-
-| <syntaxhighlight lang="sparql" inline>ex:parent/ex:parent</syntaxhighlight> || sequence (length 2)
+| wdt:P279/wdt:P279 || two hops (sequence)
+|-
+| wdt:P279+ || one or more hops
+|-
+| wdt:P279* || zero or more hops (transitive)
 |-
-| <syntaxhighlight lang="sparql" inline>ex:parent+</syntaxhighlight> || one or more
+| wdt:P279? || zero or one hop
 |-
-| <syntaxhighlight lang="sparql" inline>ex:parent*</syntaxhighlight> || zero or more
+| wdt:P279|wdt:P31 || either property
 |-
-| <syntaxhighlight lang="sparql" inline>ex:parent?</syntaxhighlight> || zero or one
+| ^wdt:P279 || inverse direction
 |-
-| <syntaxhighlight lang="sparql" inline>ex:p1|ex:p2</syntaxhighlight> || either property
+| !wdt:P279 || any property except P279
+|}
+A path chains several properties into one pattern. The dog example uses
+'''subclass of''' (wdt:P279). Compare the direct pattern with the transitive
+(<syntaxhighlight lang="sparql" inline>*</syntaxhighlight> = zero or more hops):
+{| class="wikitable"
+! Pattern !! What it matches !! Live example !! Returns
 |-
-| <syntaxhighlight lang="sparql" inline>^ex:parent</syntaxhighlight> || inverse direction
+| <syntaxhighlight lang="sparql" inline>?x wdt:P279 wd:Q144</syntaxhighlight> || classes that are a '''direct''' kind of dog (one hop) || <syntaxhighlight lang="sparql" inline>?x wdt:P279 wd:Q144</syntaxhighlight> || Rottweiler, Swedish Vallhund — 314
 |-
-| <syntaxhighlight lang="sparql" inline>!ex:p1</syntaxhighlight> || any property except p1
+| <syntaxhighlight lang="sparql" inline>?x wdt:P279* wd:Q144</syntaxhighlight> || classes that are dog or any kind-of-kind-of-dog (any number of hops) || <syntaxhighlight lang="sparql" inline>?x wdt:P279* wd:Q144</syntaxhighlight> || adds sub-breeds like Norman Hound → scent hound → dog — 511
 |}
+The <syntaxhighlight lang="sparql" inline>*</syntaxhighlight> finds things several hops away that a
+single triple cannot:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?thing ?thingLabel WHERE {
+  ?thing wdt:P279* wd:Q144 .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+LIMIT 3
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+Lapponian Herder
+autism assistance dog
+diabetic alert dog
+</syntaxhighlight>
+(These are sub-subclasses: Lapponian Herder → herding dog → dog.)
+<blockquote>'''Gotcha:''' a variable that appears only inside a path is not bound, so it cannot be selected.
+A two-hop path (<syntaxhighlight lang="sparql" inline>wdt:P279/wdt:P279</syntaxhighlight>) finds dogs two levels down (bloodhound, beagle) — but the intermediate hop is anonymous, so there is nothing to select for it:
+<syntaxhighlight lang="sparql" copy>
+# Path form: intermediate hop is anonymous — ?mid is not available
+SELECT ?xLabel WHERE {
+  ?x wdt:P279/wdt:P279 wd:Q144 .
+  ?x rdfs:label ?xLabel . FILTER(LANG(?xLabel) = "en")
+}
+LIMIT 3
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+bloodhound
+beagle
+Chesapeake Bay Retriever
+</syntaxhighlight>
+To select the intermediate value, write two explicit triples with a variable:
+<syntaxhighlight lang="sparql" copy>
+# Explicit form: ?mid is selectable
+SELECT ?xLabel ?midLabel WHERE {
+  ?x wdt:P279 ?mid .
+  ?mid wdt:P279 wd:Q144 .
+  ?x rdfs:label ?xLabel . FILTER(LANG(?xLabel) = "en")
+  ?mid rdfs:label ?midLabel . FILTER(LANG(?midLabel) = "en")
+}
+LIMIT 3
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+shepherd dog        pastoral dog
+livestock guardian dog   pastoral dog
+Canadian Eskimo Dog      inuit sledge dog
+</syntaxhighlight>
+</blockquote>
 == Aggregates ==
-<syntaxhighlight lang="sparql">
+Aggregates collapse many rows into one per group. All examples use the same
-SELECT ?p (COUNT(?s) AS ?n) (SUM(?x) AS ?total) (SAMPLE(?o) AS ?any)
+three countries (China, US, India).
-WHERE { ?s ?p ?o . ?s ex:val ?x }
-GROUP BY ?p
+'''COUNT''' — how many values (the running example counts instances per
-HAVING (COUNT(?s) > 2)
+animal; here: values of <syntaxhighlight lang="sparql" inline>wdt:P1082</syntaxhighlight> for the three countries):
+<syntaxhighlight lang="sparql" copy>
+SELECT (COUNT(?population) AS ?n) WHERE {
+  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
+  ?country wdt:P1082 ?population .
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
 </syntaxhighlight>
-Other aggregates: <syntaxhighlight lang="sparql" inline>AVG() MIN() MAX()</syntaxhighlight>,
+'''SUM''' — combined population of the three:
-<syntaxhighlight lang="sparql" inline>GROUP_CONCAT(?o; SEPARATOR=", ")</syntaxhighlight>.
-== Subqueries ==
+<syntaxhighlight lang="sparql" copy>
+SELECT (SUM(?population) AS ?total) WHERE {
+  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
+  ?country wdt:P1082 ?population .
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+3071094235
+</syntaxhighlight>
+'''AVG''' — mean population of the three:
+<syntaxhighlight lang="sparql" copy>
+SELECT (AVG(?population) AS ?avg) WHERE {
+  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
+  ?country wdt:P1082 ?population .
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+1023698078.33
+</syntaxhighlight>
+'''MIN / MAX''' — smallest and largest of the three:
+<syntaxhighlight lang="sparql" copy>
+SELECT (MIN(?population) AS ?min) (MAX(?population) AS ?max) WHERE {
+  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
+  ?country wdt:P1082 ?population .
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+340110988  1404890000
+</syntaxhighlight>
+'''SAMPLE''' — one arbitrary value (useful to squash duplicates):
+<syntaxhighlight lang="sparql" copy>
+SELECT (SAMPLE(?countryLabel) AS ?anyCountry) WHERE {
+  VALUES ?country { wd:Q148 wd:Q30 wd:Q668 }
+  ?country wdt:P1082 ?population .
+  ?country rdfs:label ?countryLabel .
+  FILTER(LANG(?countryLabel) = "en")
+}
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+United States
+</syntaxhighlight>
+'''GROUP_CONCAT''' — Einstein's awards in one cell:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?personLabel (GROUP_CONCAT(?awardLabel; SEPARATOR=", ") AS ?awards) WHERE {
+  VALUES ?person { wd:Q937 }
+  ?person wdt:P166 ?award .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+GROUP BY ?personLabel
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+Albert Einstein  Nobel Prize in Physics, …
+</syntaxhighlight>
+'''GROUP BY + HAVING''' — the running example, filtered to groups with more
+than 400 instances:
+<syntaxhighlight lang="sparql" copy>
+SELECT ?animalLabel (COUNT(?item) AS ?n) WHERE {
+  VALUES ?animal { wd:Q144 wd:Q146 }
+  ?item wdt:P31 ?animal .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+}
+GROUP BY ?animal ?animalLabel
+HAVING (COUNT(?item) > 400)
+</syntaxhighlight>
+Result:
+<syntaxhighlight lang="text" copy>
+dog  553
+</syntaxhighlight>
+<blockquote>'''Gotcha:''' aggregates need GROUP BY for every non-aggregated variable. Forgetting one is a '''query error''', not a wrong result.
+Missing GROUP BY for <syntaxhighlight lang="sparql" inline>?animalLabel</syntaxhighlight>:
-<syntaxhighlight lang="sparql">
+<syntaxhighlight lang="sparql" copy>
-SELECT ?s WHERE {
+SELECT ?animalLabel (COUNT(?item) AS ?n) WHERE {
-  { SELECT ?s (MAX(?v) AS ?maxv) WHERE { ?s ex:val ?v } GROUP BY ?s }
+  VALUES ?animal { wd:Q144 wd:Q146 }
-   ?s ex:val ?maxv
+  ?item wdt:P31 ?animal .
+   ?animal rdfs:label ?animalLabel .
+  FILTER(LANG(?animalLabel) = "en")
 }
 </syntaxhighlight>
-== Federated queries (SERVICE) ==
+Result:
+<syntaxhighlight lang="text" copy>
+ERROR: Bad aggregate — every non-aggregated variable needs GROUP BY
+</syntaxhighlight>
+</blockquote>
+== Subqueries ==
+A query inside a query — useful for "the X with the max Y" patterns.
+'''The most populous country, computed via a subquery:'''
-<syntaxhighlight lang="sparql">
+<syntaxhighlight lang="sparql" copy>
-SELECT ?label WHERE {
+SELECT ?countryLabel ?max WHERE {
-   ?s ex:ref ?w .
+   {
-  SERVICE <https://www.wikidata.org/sparql> {
+    SELECT (MAX(?population) AS ?max) WHERE {
-    ?w rdfs:label ?label . FILTER(LANG(?label) = "en")
+      ?c wdt:P31 wd:Q6256 .
+      ?c wdt:P1082 ?population .
+    }
    }
+  ?country wdt:P31 wd:Q6256 .
+  ?country wdt:P1082 ?max .
+  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
 }
 </syntaxhighlight>
-== Common tasks ==
+Result:
+<syntaxhighlight lang="text" copy>
+China  1404890000
+</syntaxhighlight>
+== SERVICE (labels, federation) ==
-* '''Count rows''': <syntaxhighlight lang="sparql" inline>SELECT (COUNT(*) AS ?n) WHERE { ?s ?p ?o }</syntaxhighlight>
+The label service turns entity IDs into human-readable labels — used in most
-* '''Deduplicate''': add <syntaxhighlight lang="sparql" inline>DISTINCT</syntaxhighlight>
+queries above:
-* '''Reverse direction''': <syntaxhighlight lang="sparql" inline>?child ^ex:parent ?parent</syntaxhighlight>
-* '''Check existence''': <syntaxhighlight lang="sparql" inline>ASK</syntaxhighlight>
-* '''JSON output''': append <syntaxhighlight lang="text" inline>&format=json</syntaxhighlight> to the endpoint URL
-== Gotchas ==
+<syntaxhighlight lang="sparql" copy>
+SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
+# then reference ?xLabel for every ?x in the query
+</syntaxhighlight>
-* The default is '''AND (join)''', not OR — use UNION for alternatives.
+<syntaxhighlight lang="sparql" copy>
-* An unbound variable in <syntaxhighlight lang="sparql" inline>FILTER</syntaxhighlight> makes the row fail (filter is not "true" for unbound) — guard with <syntaxhighlight lang="sparql" inline>BOUND()</syntaxhighlight> or use OPTIONAL.
+# Federating to another endpoint (needs the remote's own IRIs, e.g. via owl:sameAs)
-* Variables used only inside a property path (e.g. <syntaxhighlight lang="sparql" inline>?s ex:p1/ex:p2 ?o</syntaxhighlight>) cannot be selected.
+SELECT ?cityLabel WHERE {
-* Blank-node labels (e.g. <syntaxhighlight lang="sparql" inline>_:x</syntaxhighlight>) are local to one query — they are not IRIs.
+  wd:Q64 wdt:P36 ?city .
-* Aggregates require GROUP BY for non-aggregated variables; forgetting it mixes unrelated rows.
+  ?city owl:sameAs ?dbpediaCity .
-* <syntaxhighlight lang="sparql" inline>LIMIT 0</syntaxhighlight> returns no rows but still validates the query.
+  SERVICE <https://dbpedia.org/sparql> {
+    ?dbpediaCity rdfs:label ?cityLabel .
+    FILTER(LANG(?cityLabel) = "en")
+  }
+}
+</syntaxhighlight>
 == Further reading ==
@@ Line 172: / Line 850: @@
 * [https://www.wikidata.org/wiki/Wikidata:SPARQL_tutorial Wikidata SPARQL tutorial] — the recommended tutorial
 * [https://www.w3.org/TR/sparql11-query/ SPARQL 1.1 Query Language] — official spec
-* [[Help:Contributing/query]] — querying a specific instance (endpoint, prefixes, label service)
+* [https://query.wikidata.org/ Wikidata Query Service] — the example endpoint used here
+* [[Help:Contributing/query]] — querying a different instance (endpoint, prefixes, label service)

Cheatsheets:SPARQL: Difference between revisions

SeedBot (talk | contribs)

Latest revision as of 09:45, 23 August 2026

Basic example

Building a query

Query forms

Solution modifiers

VALUES & BIND

FILTER

UNION, OPTIONAL, MINUS

Property paths

Aggregates

Subqueries

SERVICE (labels, federation)

Further reading

Navigation menu

Search