SPARQL Query Language

A SPARQL Query Language is an RDF Query Language.

Context:
- …
Counter-Example(s):
- RQL.
- Turtle Syntax.
See: RDF DBMS, Lightweight Ontology, XQuery, W3C, Jena (Framework), Resource Description Framework.

References

2016

(Wikipedia, 2016) ⇒ http://wikipedia.org/wiki/SPARQL Retrieved:2016-3-24.
- SPARQL (pronounced "sparkle", a recursive acronym for SPARQL Protocol and RDF Query Language) is an RDF query language, that is, a semantic query language for databases, able to retrieve and manipulate data stored in Resource Description Framework (RDF) format. It was made a standard by the RDF Data Access Working Group (DAWG) of the World Wide Web Consortium, and is recognized as one of the key technologies of the semantic web. On 15 January 2008, SPARQL 1.0 became an official W3C Recommendation, and SPARQL 1.1 in March, 2013. SPARQL allows for a query to consist of triple patterns, conjunctions, disjunctions, and optional patterns. Implementations for multiple programming languages exist. There exist tools that allow one to connect and semi-automatically construct a SPARQL query for a SPARQL endpoint, for example ViziQuer. In addition, there exist tools that translate SPARQL queries to other query languages, for example to SQL and to XQuery.

2009

(Alkhateeb et al., 2009) ⇒ Faisal Alkhateeb, Jean-François Baget, and Jérôme Euzenat. (2009). “Extending SPARQL with Regular Expression Patterns (for Querying RDF).” In: Web Semantics: Science, Services and Agents on the World Wide Web. doi:10.1016/j.websem.2009.02.002
- QUOTE: RDF is a knowledge representation language dedicated to the annotation of resources within the framework of the semantic web. Among the query languages for RDF, SPARQL allows querying RDF through graph patterns, i.e., RDF graphs involving variables. Other languages, inspired by the work in databases, use regular expressions for searching paths in RDF graphs.

2008

(Quilitz & Leser, 2008) ⇒ Bastian Quilitz, and Ulf Leser. (2008). “Querying Distributed RDF Data Sources with SPARQL.” In: Proceedings of the 5th European Semantic Web Conference (ESWC 2008).
- ABSTRACT: Integrated access to multiple distributed and autonomous RDF data sources is a key challenge for many semantic web applications. As a reaction to this challenge, SPARQL, the W3C Recommendation for an RDF query language, supports querying of multiple RDF graphs. However, the current standard does not provide transparent query federation, which makes query formulation hard and lengthy. Furthermore, current implementations of SPARQL load all RDF graphs mentioned in a query to the local machine. This usually incurs a large overhead in network traffic, and sometimes is simply impossible for technical or legal reasons. To overcome these problems we present DARQ, an engine for federated SPARQL queries. DARQ provides transparent query access to multiple SPARQL services, i.e., it gives the user the impression to query one single RDF graph despite the real data being distributed on the web. A service description language enables the query engine to decompose a query into sub-queries, each of which can be answered by an individual service. DARQ also uses query rewriting and cost-based query optimization to speed-up query execution. Experiments show that these optimizations significantly improve query performance even when only a very limited amount of statistical information is available. DARQ is available under GPL License at http://darq.sf.net/

2007

(Obitko, 2007) ⇒ Marek Obitko. (2007). “Translations Between Ontologies in Multi-agent Systems - Ontology Operations].” PhD Thesis, Czech Technical University http://www.obitko.com/tutorials/ontologies-semantic-web/rdf-query-language-sparql.html
- The Simple Protocol and RDF Query Language (SPARQL) is a SQL-like language for querying RDF data. For expressing RDF graphs in the matching part of the query, TURTLE syntax is used(...)

The SPARQL specification is in the state of working draft (state at the end of 2006), but it is already implemented in some software packages and it seems that it will become the main RDF querying language for the semantic web. The specification of protocol for a SPARQL web service is available as well - SPARQL then serves as a RDF data access protocol.