SPARQL

SPARQL is the standard SQL-like query language for retrieving and manipulating data stored in Resource Description Framework (RDF) format.

SPARQL (SPARQL Protocol and RDF Query Language) serves as the primary mechanism for interacting with the Semantic Web. It enables developers to execute complex joins across diverse data sources by focusing on graph patterns rather than relational tables. Using a syntax familiar to SQL users (SELECT, WHERE, and FILTER clauses), it queries triple stores like Apache Jena or Virtuoso to extract structured information from linked data. Version 1.1 expanded the toolset to include subqueries, property paths, and aggregate functions (SUM, COUNT, and AVG), making it a robust choice for knowledge graphs and open data initiatives.

https://www.w3.org/TR/sparql11-query/