What is optional SPARQL?

OPTIONAL is a binary operator that combines two graph patterns. The optional pattern is any group pattern and may involve any SPARQL pattern types. If the group matches, the solution is extended, if not, the original solution is given (q-opt3.

Which query language is most commonly used to process RDF database?

SPARQL
An RDF query language is a computer language, specifically a query language for databases, able to retrieve and manipulate data stored in Resource Description Framework (RDF) format. SPARQL has emerged as the standard RDF query language, and in 2008 became a W3C recommendation.

What is the result type of an SPARQL construct query?

The CONSTRUCT query form returns an RDF graph. The graph is built based on a template which is used to generate RDF triples based on the results of matching the graph pattern of the query. Results: @prefix org: .

What is blank node in SPARQL?

Blank nodes in graph patterns act as variables, not as references to specific blank nodes in the data being queried. Blank nodes are indicated by either the label form, such as “_:abc”, or the abbreviated form “[]”. A blank node that is used in only one place in the query syntax can be indicated with [].

Does Neo4j support SPARQL?

Since the Neo4j graph database is not a triple store, it is not equipped with a SPARQL query engine. However, Neo4j offers Cypher and for many semantic applications it should be possible to translate SPARQL to Cypher queries.

What does bind do in SPARQL?

A SPARQL IF statement allows you to select between two values based on a boolean (true or false) statement. BIND statements let you set the value of a variable.

What is the difference between SPARQL and SQL?

In considering the differences, it is important to keep in mind that SPARQL is designed to query RDF data while SQL is designed to query relational data. As such, both languages and their respective advantages closely reflect the data models they work with.

What are RDF graphs?

The Resource Description Framework, more commonly known as RDF, is a graph data model that formally describes the semantics, or meaning of information. It also represents metadata, that is, data about data. RDF consists of triples. The parts of a triple, the subject, predicate, and object, represent links in a graph.

Is Neo4j a RDF?

It is widely known that Neo4j is able to load and write RDF. Labeled Property Graphs (LPG) and the Resource Description Framework (RDF) have a common ground: both consider data as a graph .

What is FOAF in SPARQL?

Dataset: Friend of a Friend (FOAF) FOAF is a standard RDF vocabulary for describing people and relationships. Tim Berners-Lee’s FOAF information available at http://www.w3.org/People/Berners-Lee/card.

Is SPARQL like SQL?

SPARQL vs SQL 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.