Sparqlify: a SPARQL-SQL rewriter

Sparqlify is a SPARQL-SQL rewriter that enables one to define RDF views on relational databases and query them with SPARQL. It is currently in alpha state and powers the Linked-Data Interface of the LinkedGeoData Server – i.e. it provides access to billions of virtual triples from the OpenStreetMap database.

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Key Features

  • A novel syntax for view definitions inspired by SQL's CREATE VIEW statement. We believe this to lower the learning curve for defining RDB-RDF mappings.
  • A query is rewritten into a single SQL statement, giving all control over query planning to the underlying database system.
  • Support of geo-spatial functions: In general, Sparqlify supports mapping custom SPARQL functions to relational ones. Some mappings for PostGIS are already provided (e.g. intersection with polygons).

Limitations

Please be aware that Sparqlify is currently in alpha state and the following limitations hold:

  • For the moment, only the PostgreSQL database system is supported.
  • Only a subset of SPARQL 1.0 + Sub-Queries is supported: For instance, the implementation of aggregate functions including COUNT is still pending.
  • Support for Sparql 1.1 property paths is very unlikely in the near future.

Project Team

Former Members

Publications

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News

DBpedia Masterclass @ Connected Data World ( 2021-11-02T11:17:30+01:00 by Julia Holze)

2021-11-02T11:17:30+01:00 by Julia Holze

Dear all, We are proud to announce that we will organize the masterclass “DBpedia Knowledge Graph Tutorial for Beginners” at the Connected Data World event. Read more about "DBpedia Masterclass @ Connected Data World"

DBpedia Day @ SEMANTiCS 2021 ( 2021-07-30T09:54:45+02:00 by Julia Holze)

2021-07-30T09:54:45+02:00 by Julia Holze

We are happy to announce that we are partnering again with the SEMANTiCS Conference which will host this year’s DBpedia Day on September 9, 2021. Read more about "DBpedia Day @ SEMANTiCS 2021"

LDK Conference meets DBpedia in Zaragoza, Spain ( 2021-07-09T10:37:27+02:00 by Julia Holze)

2021-07-09T10:37:27+02:00 by Julia Holze

We are happy to announce that we will organize a DBpedia Tutorial on September 1, 2021 in Zaragoza, Spain. This DBpedia tutorial will be part of the Language, Data and Knowledge conference 2021. Read more about "LDK Conference meets DBpedia in Zaragoza, Spain"

Assessing Language Identification Over DBpedia ( 2021-05-04T23:27:40+02:00 EdgardMarx)

2021-05-04T23:27:40+02:00 EdgardMarx

Large-scale multilingual knowledge bases (KBs) are the key for cross-lingual and multilingual applications such as Question Answering, Machine  Translation,  and  Search. Read more about "Assessing Language Identification Over DBpedia"

DBpedia Tutorial @ Knowledge Graph Conference 2021 ( 2021-04-09T13:20:50+02:00 by Julia Holze)

2021-04-09T13:20:50+02:00 by Julia Holze

On May 4, 2021 we will organize a tutorial at the Knowledge Graph Conference (KGC) 2021. Read more about "DBpedia Tutorial @ Knowledge Graph Conference 2021"