Wikidata Query Skill

Wikidata Query Skill

When to Use This Skill

Use this skill when users want to:

• Query Wikidata using natural language
• Get comprehensive, multilingual data about entities
• Access property-rich information (Wikidata has extensive properties)
• Create visualizations of Wikidata query results
• Generate HTML reports from SPARQL queries
• Query data with better temporal coverage than DBpedia

Core Capabilities

✅ Natural Language to SPARQL: Convert user questions into valid Wikidata SPARQL ✅ Query Execution: Execute queries against Wikidata Query Service ✅ HTML Generation: Create beautiful, interactive HTML result pages ✅ Multiple Output Formats: JSON, Markdown tables, or HTML ✅ Label Service: Automatic label resolution for human-readable results

Wikidata Endpoint

SPARQL Endpoint: https://query.wikidata.org/sparql Accept Header: application/sparql-results+json Method: HTTP GET with URL-encoded query User-Agent: Required (use Claude-Code-Wikidata-Skill/1.0)

Wikidata Naming Convention

Properties: wdt:P### (e.g., wdt:P57 for director) Entities: wd:Q### (e.g., wd:Q51566 for Spike Lee) Service: wikibase:label for automatic label resolution

Common Wikidata Properties

P31  - instance of
P57  - director
P577 - publication date
P2130 - cost/budget
P50  - author
P170 - creator
P19  - place of birth
P20  - place of death
P569 - date of birth
P570 - date of death
P27  - country of citizenship
P106 - occupation
P735 - given name
P734 - family name
P1082 - population
P36  - capital

Query Conversion Workflow

When a user provides a natural language prompt:

1. Identify Entity

Find the Wikidata Q-number for the main subject:

• Use descriptive search if needed
• Example: "Spike Lee" → wd:Q51566

2. Map to Wikidata Properties

Common mappings:

• "directed by" → wdt:P57
• "release date" / "published" → wdt:P577
• "budget" → wdt:P2130
• "born in" → wdt:P19
• "author" / "written by" → wdt:P50
• "population" → wdt:P1082
• "capital" → wdt:P36

3. Construct SPARQL Query

Template with Label Service:

SELECT DISTINCT ?item ?itemLabel ?property
WHERE {
  ?item wdt:P### wd:Q### ;     # property: entity
        wdt:P31 wd:Q### .       # instance of: type
  OPTIONAL { ?item wdt:P### ?property . }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY <sort_criteria>
LIMIT <number>

CRITICAL: Always include the label service for human-readable output!

4. Execute Query

Use curl with proper headers:

curl -s -G "https://query.wikidata.org/sparql" \
  -H "Accept: application/sparql-results+json" \
  -H "User-Agent: Claude-Code-Wikidata-Skill/1.0" \
  --data-urlencode "query=<SPARQL_QUERY>"

5. Generate Output

Options:

• JSON: Raw query results
• Markdown Table: Formatted for terminal display
• HTML Page: Interactive, styled results page with Wikidata branding

Example Query Patterns

Pattern 1: Films by Director

User: "Show me movies directed by Spike Lee"

SPARQL:

SELECT DISTINCT ?film ?filmLabel ?publicationDate ?budget
WHERE {
  ?film wdt:P57 wd:Q51566 ;        # director: Spike Lee
        wdt:P31 wd:Q11424 .         # instance of: film
  OPTIONAL { ?film wdt:P577 ?publicationDate . }
  OPTIONAL { ?film wdt:P2130 ?budget . }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY DESC(?publicationDate)

Pattern 2: Books by Author

User: "List books written by J.K. Rowling"

SPARQL:

SELECT DISTINCT ?book ?bookLabel ?publicationDate
WHERE {
  ?book wdt:P50 wd:Q34660 ;        # author: J.K. Rowling
        wdt:P31 wd:Q7725634 .      # instance of: literary work
  OPTIONAL { ?book wdt:P577 ?publicationDate . }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY ?publicationDate

Pattern 3: People by Occupation

User: "Who are famous physicists born in the 20th century?"

SPARQL:

SELECT ?person ?personLabel ?birthDate ?birthPlaceLabel
WHERE {
  ?person wdt:P106 wd:Q169470 ;     # occupation: physicist
          wdt:P569 ?birthDate .     # date of birth
  OPTIONAL { ?person wdt:P19 ?birthPlace . }
  FILTER(YEAR(?birthDate) >= 1900 && YEAR(?birthDate) < 2000)
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY ?birthDate
LIMIT 50

Pattern 4: Geographic Queries

User: "What are the capitals of European countries?"

SPARQL:

SELECT ?country ?countryLabel ?capital ?capitalLabel ?population
WHERE {
  ?country wdt:P30 wd:Q46 ;         # continent: Europe
           wdt:P36 ?capital .       # capital
  ?capital wdt:P1082 ?population .  # population
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY DESC(?population)

Pattern 5: Award Winners

User: "List Nobel Prize in Literature winners"

SPARQL:

SELECT ?person ?personLabel ?awardYear
WHERE {
  ?person wdt:P166 wd:Q37922 ;      # award received: Nobel Prize in Literature
          wdt:P569 ?birthDate .
  OPTIONAL { ?person wdt:P166 ?award .
             ?award wdt:P585 ?awardYear . }
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
ORDER BY DESC(?awardYear)

Finding Wikidata Entities

If you need to find a Q-number for an entity:

Method 1: Search Query

SELECT ?item ?itemLabel ?itemDescription
WHERE {
  ?item rdfs:label "Spike Lee"@en .
  ?item wdt:P106 wd:Q2526255 .      # occupation: film director
  SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
}
LIMIT 5

Method 2: Use Wikidata search

• Go to https://www.wikidata.org
• Search for the entity
• Note the Q-number in the URL

HTML Template Generation

When generating HTML results:

Required Elements

1. Title: Question or query description
2. Statistics: Number of results
3. Table: Results with hyperlinked Wikidata entities
4. SPARQL Query Display: Show the executed query with syntax highlighting
5. Footer: Link to Wikidata, attribution, license info

Wikidata Branding

• Use blue/green color scheme (Wikidata colors)
• Include Wikidata logo reference
• Link to https://www.wikidata.org
• Mention collaborative nature

HTML Template Structure

<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>[Query Description] - Wikidata</title>
    <style>
        /* Blue/green Wikidata theme */
        /* Responsive design */
        /* Interactive elements */
    </style>
</head>
<body>
    <div class="container">
        <h1>[Question/Title]</h1>
        <div class="wikidata-badge">Wikidata</div>
        <div class="stats">[Results count]</div>
        <table>[Results with Wikidata links]</table>
        <div class="sparql-query">[Query code]</div>
        <div class="footer">[Attribution + CC0 license]</div>
    </div>
</body>
</html>

Error Handling

Timeout Errors

Wikidata Query Service has query timeout limits:

• Add LIMIT clause (default: 100)
• Simplify complex joins
• Remove unnecessary OPTIONAL clauses

No Results

• Check entity Q-numbers
• Verify property P-numbers
• Suggest using Wikidata search

Label Service Issues

• Always include: SERVICE wikibase:label { bd:serviceParam wikibase:language "en". }
• Use ?variableLabel to get human-readable names

Best Practices

1. Always use Label Service: Makes results human-readable
2. Check Q/P numbers: Verify entity and property identifiers
3. Add LIMIT: Default to LIMIT 100
4. Use OPTIONAL: For properties that may not exist
5. Filter by language: When not using label service
6. Order results: Make output meaningful
7. Include User-Agent: Required by Wikidata Query Service

Wikidata vs DBpedia

Use Wikidata when:

• Need better temporal data (publication dates, birth dates)
• Want multilingual support
• Need comprehensive property coverage
• Require structured identifiers (Q/P system)

Use DBpedia when:

• Querying Wikipedia-specific data
• Need budget/financial information (better coverage)
• Working with English-only queries

Example Session

User: "List all films directed by Christopher Nolan with release dates and budgets"

Assistant: "I'll query Wikidata for Christopher Nolan's films.

First, I need to find his Wikidata ID..." [Searches and finds wd:Q25191]

"Executing SPARQL query against Wikidata Query Service..."

[Constructs and executes query]

"Found 12 films! Would you like the results as:

1. JSON
2. Markdown table
3. HTML page"

User: "HTML page"

Assistant: [Generates beautiful HTML page with Wikidata branding]

"✓ HTML page generated and saved to: ./christopher_nolan_films.html ✓ 12 films found ✓ 10 films with release dates ✓ 5 films with budget information"

Output Preferences

Always ask the user:

"Would you like the results as:
1. JSON (raw data)
2. Markdown table (terminal display)
3. HTML page (interactive visualization)"

Scope

This skill handles:

• Queries about entities in Wikidata
• Structured data extraction with properties
• Multi-property queries
• Temporal queries (dates, years)
• Result formatting and visualization

This skill does NOT handle:

• Full-text search (use Wikidata search instead)
• Data modification (read-only queries)
• Non-English labels (configure in label service)

Important Notes

• User-Agent Required: Always include User-Agent header
• Rate Limiting: Be respectful of query service limits
• Query Timeout: 60 seconds maximum
• License: All Wikidata data is CC0 (public domain)

Version: 1.0.0 Endpoint: https://query.wikidata.org/sparql Data Source: Wikidata (collaborative knowledge base) License: CC0 (public domain)