SPARQL

SPARQL (SPARQL Protocol and RDF Query Language) is the standard query language for retrieving and manipulating data stored in RDF (Resource Description Framework) format. It is to RDF databases what SQL is to relational databases and Cypher is to Neo4j property graphs.

SPARQL queries match patterns of triples using a syntax based on the subject-predicate-object structure. For example, SELECT ?company WHERE { :Alice :worksFor ?company . } finds all companies Alice works for by matching triples where Alice is the subject and worksFor is the predicate. SPARQL supports multi-hop queries, aggregation, optional patterns, and federated queries across multiple endpoints.

SPARQL is widely used in the semantic web ecosystem, with major knowledge bases like Wikidata, DBpedia, and Bio2RDF providing public SPARQL endpoints. While Cypher is more popular in industry applications using Neo4j, SPARQL is the standard for academic, government, and linked open data applications. Understanding both query languages provides flexibility in working with different knowledge graph implementations.