Technical Introduction
to Wikidata
Docker
Wikimedia
Wikidata
Wikidata: Namespaces
- «Wiki ones»: User, Wikidata, Category, etc.
- Wikibase ones: Item, Property (both entities)
Wikidata: Concepts
Wikidata: Concepts
- Labels
- Descriptions
- Aliases
- Sitelinks
- Statements
Wikidata: Statements
Wikidata: Data Types
Triple
Paul Schuster was born in Dresden
RDF
(Resource Description Framework)
RDF Serialisation formats
- RDF/XML
- Turtle
- JSON-LD
- etc.
Wikidata: Exports
Wikidata:
Popular properties
Wikidata and Wikipedia(s)
Used in
- Interwiki
- Infoboxes
- etc.
Wikidata and Wikipedia(s)
Linkage at the API level
Example: Les Misérables
query, pageprops, -> wikibase_item (+ info)
Extra information:
wbentityusage
wblistentityusage
Wikidata API access
MediaWiki API access: Like any other MediaWiki.
Access via JSON (or other) exports
SPARQL endpoint access
Wikidata API clients
Semantic Web
Linked (Open) Data
SPARQL
SPARQL Protocol and RDF Query Language
Similar to SQL, but for the Semantic Web
SPARQL: Endpoints and interfaces
Interface to multiple endpoints
Wikidata SPARQL inteface
SPARQL: Prefixes
PREFIX wd: <http://www.wikidata.org/entity/>
PREFIX wds: <http://www.wikidata.org/entity/statement/>
PREFIX wdv: <http://www.wikidata.org/value/>
PREFIX wdt: <http://www.wikidata.org/prop/direct/>
PREFIX wikibase: <http://wikiba.se/ontology#>
PREFIX p: <http://www.wikidata.org/prop/>
PREFIX ps: <http://www.wikidata.org/prop/statement/>
PREFIX pq: <http://www.wikidata.org/prop/qualifier/>
PREFIX rdfs: <http://www.w3.org/2000/01/rdf-schema#>
Some used by Wikidata
SPARQL: Prefixes
Other external ones
Example: Universities by Page Rank
SPARQL: Queries
SPARQL: Queries
Additional examples:
SPARQL: API Access
Example for Wikidata: https://query.wikidata.org/sparql
SPARQL client in Python
Wikidata Dumps
- JSON
- XML
- RDF
- etc.
Entities
Wikidata dumps: Usage
Using Unix tools, regexp, and then processing JSON (one per line)
Convenient tool: wikidata-filter
Toy dataset: public universities in Wikidata
Convenient NodeJS image: https://github.com/toniher/docker-nodejs-wikidata
Wikidata dumps: Usage
Example:
Count all public universities in Spain
zcat unipubli.json.gz | wikidata-filter --claim P17:Q29 | wc -l
Wikidata: Creating bots
about creation or permissions
Technical introduction to Wikidata
By Similis.cc
Technical introduction to Wikidata
Short tutorial about Wikidata and its technical usage.
