What is the result type of an SPARQL construct query?
SPARQL contains capabilities for querying required and optional graph patterns along with their conjunctions and disjunctions. SPARQL also supports extensible value testing and constraining queries by source RDF graph. The results of SPARQL queries can be results sets or RDF graphs.
What is FOAF in SPARQL?
Dataset: Friend of a Friend (FOAF) @prefix card: .
What is prefix in SPARQL?
“PREFIX”, however (without the “@”), is the SPARQL instruction for a declaration of a namespace prefix. It allows you to write prefixed names in queries instead of having to use full URIs everywhere. So it’s a syntax convenience mechanism for shorter, easier to read (and write) queries.
What is DBpedia ontology?
The DBpedia Ontology is a shallow, cross-domain ontology, which has been manually created based on the most commonly used infoboxes within Wikipedia. The ontology currently covers 685 classes which form a subsumption hierarchy and are described by 2,795 different properties.
Is SPARQL an API?
The SPARQL API is different from the other Europeana APIs in that it allows you to explore connections between Europeana data and outside data sources, like VIAF, Iconclass, Getty Vocabularies (AAT), Geonames, Wikidata, and DBPedia.
Is SPARQL a NoSQL?
Just like SQL allows users to retrieve and modify data in a relational database, SPARQL provides the same functionality for NoSQL graph databases like Ontotext’s GraphDB. In addition, a SPARQL query can also be executed on any database that can be viewed as RDF via a middleware.
Is DBpedia reliable?
For the API availability, DBpedia is the most reliable; its SPARQL endpoind is roughly available at every time.
Who invented SPARQL?
W3C
On 15 January 2008, SPARQL 1.0 was acknowledged by W3C as an official recommendation, and SPARQL 1.1 in March, 2013….SPARQL.
| Paradigm | Query language |
| Developer | W3C |
| First appeared | 2008 |
| Stable release | 1.1 / 21 March 2013 |
| Major implementations |
|---|
What is endpoint in SPARQL?
A SPARQL Endpoint is a Point of Presence on an HTTP network that’s capable of receiving and processing SPARQL Protocol requests. It is identified by a URL commonly referred to as a SPARQL Endpoint URL.
Is SPARQL a graph database?
What is SPARQL variable binding results XML format?
The SPARQL Variable Binding Results XML Format can be used to serialize the result set from a SELECT query or the boolean result of an ASK query. The SELECT form of results returns variables and their bindings directly.
What are SPARQL property paths and how to use them?
As we have just seen SPARQL property paths can be used to find pairs of nodes connected via a complex path of edges. But these property paths only return the start and end nodes of a path and not the intermediate nodes within the path.
What is a SPARQL expression?
SPARQL expressions are constructed according to the grammar and provide access to functions (named by IRI) and operator functions (invoked by keywords and symbols in the SPARQL grammar). SPARQL operators can be used to compare the values of typed literals:
What is the difference between RDF merge and SPARQL?
In an RDF merge, blank nodes in the merged graph are not shared with blank nodes from the graphs being merged. A SPARQL query may specify the dataset to be used for matching by using the FROM clause and the FROM NAMED clause to describe the RDF dataset.