Cheatsheets:SPARQL

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

Cheatsheet for querying this instance's data with SPARQL against the Wikibase Query Service.

Quick start

The endpoint is https://wikibase.ronzz.org/sparql. A minimal query (returns one column of entity URIs):

PREFIX wd: <https://wikibase.ronzz.org/entity/>
PREFIX wdt: <https://wikibase.ronzz.org/prop/direct/>
SELECT ?item WHERE { ?item wdt:P31 wd:Q161 . } LIMIT 10

Query structure

| Part | Role | |------|------| | PREFIX | Namespace shorthand; must be declared (see gotchas) | | SELECT | Variables to return | | WHERE | Triple patterns in curly braces | | FILTER / VALUES / BIND | Constraints and computed values | | LIMIT / OFFSET | Paging (nginx enforces a 300 s cap, see gotchas) |

Instance prefixes

| Prefix | Expands to | Use for | |--------|------------|---------| | wd: | https://wikibase.ronzz.org/entity/ | Items (Q…) and properties (P…) as subjects/values | | wdt: | https://wikibase.ronzz.org/prop/direct/ | Direct property statements (P…) | | wikibase: | built-in | The label service, etc. |

Basic patterns

• instance of is P1 — this instance does not mirror Wikidata's P31
• Q1 is the "Spike test item" — useful for testing, but it carries no claims
• Typical pattern: ?item wdt:P1 wd:Q161 .

FILTER, VALUES, BIND

PREFIX wd: <https://wikibase.ronzz.org/entity/>
PREFIX wdt: <https://wikibase.ronzz.org/prop/direct/>
SELECT ?item ?name WHERE {
  VALUES ?type { wd:Q161 }
  ?item wdt:P1 ?type .
  BIND(STR(?item) AS ?name)
  FILTER(CONTAINS(?name, "Q"))
}
LIMIT 10

Label service

Labels are not in the graph — use wikibase:label:

PREFIX wd: <https://wikibase.ronzz.org/entity/>
PREFIX wdt: <https://wikibase.ronzz.org/prop/direct/>
SELECT ?item ?itemLabel WHERE {
  ?item wdt:P1 ?type .
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en,fr,eo". }
}
LIMIT 10

The instance's official languages are en, fr, eo — list them in this order.

Aggregation

PREFIX wd: <https://wikibase.ronzz.org/entity/>
PREFIX wdt: <https://wikibase.ronzz.org/prop/direct/>
SELECT ?type (COUNT(?item) AS ?n) WHERE {
  ?item wdt:P1 ?type .
}
GROUP BY ?type
ORDER BY DESC(?n)
LIMIT 10

Common tasks

• Count triples: SELECT (COUNT(?s) AS ?n) WHERE { ?s ?p ?o }
• JSON output: append &format=json to the endpoint URL
• Test a fresh entity: query it via ?item wdt:P1 ?type first, then build up

Gotchas

• The default wd:/wdt: prefixes resolve to wikidata.org, not this instance — always declare them explicitly, or queries silently return 0 results.
• nginx caps SPARQL requests at 300 s — keep queries small, page with LIMIT/OFFSET.
• The WDQS updater can lag behind the wiki (known fresh-instance catch-up quirk) — a just-created entity may not appear in SPARQL immediately; re-check later.
• No Wikidata P-number mirroring — property IDs here (P1, P2, …) are local; use equivalence statements instead of assuming Wikidata numbers.

Further reading

• Help:Contributing/query — querying with SPARQL on this instance
• Wikidata SPARQL tutorial — works verbatim against any Wikibase
• SPARQL 1.1 spec