SPARQL (pronounced "sparkle", acronym for SPARQL Protocol And RDF Query Language) is an RDF query language, that is, a semantic query language for databases. With SPARQL you can extract any kind of data, with a query composed of logical combinations of triples.

Wikidata provides an SPARQL endpoint including a powerful Web-GUI since September 2015.

This book focusses on the Wikidata database, with lots of examples

Introduction

• Basics
• Wikidata Query Service
  • Introduction
• Prefixes
• Sentences
• Triples

SPARQL Statements

• SELECT
• OPTIONAL
• Filtering: FILTER, FILTER NOT EXIST and MINUS
• UNION
• SERVICEs
  • SERVICE Labels and Descriptions
  • SERVICE around and box
  • SERVICE Mediawiki Api (Wikipedia, commons etc.)
• Modifiers like GROUP BY, HAVING, ORDER BY, LIMIT
• Aggregate functions COUNT, MIN, MAX, SUM, AVG, SAMPLE and GROUP_CONCAT
  • Bad aggregate error

Advanced SPARQL topics

• Property paths and Instances and classes
• Variables
• Expressions and Functions
• Federated query
• Subqueries

WIKIDATA data representation

• WIKIDATA Qualifiers, References and Ranks
• WIKIDATA Language links and Badges
• WIKIDATA Precision, Units and Coordinates
• WIKIDATA Lexicographical data

Miscellaneous

• Views