SPARQL Aggregate Queries made easy with Diagrammatic Query Language ViziQuer

Abstract. We present a novel way to draw SPARQL aggregate queries via diagrammatic query language -ViziQuer. Since the introduction of SPARQL different graphical languages have been proposed to make SPARQL more userfriendly. In SPARQL 1.1 aggregate queries were introduced that are key to meaningful query formulation. However, diagrammatic query languages lacked this important end-user feature to make the diagrammatic SPARQL extensions powerful enough. Keywords The demonstration will show creation of aggregate SPARQL queries in the ViziQuer notation that is the main novelty of this paper. An extended outline of the design of the visual aggregate queries appears a

Making linked-data accessible: A review

Linked-Data (LD) is a paradigm that utilises the RDF triplestore to describe numerous pieces of knowledge linked together. When an entity is retrieved in LD, its associated data becomes instantly obtainable. SPARQL is the query language that allows users to access LD. On the other hand, SPARQL has a complicated syntax that necessitates previous knowledge. Thus, in order to encourage the end-users to use LD, it is crucial to allow them to obtain the data efficiently, in addition to improving their overall experience. Instead of manually constructing SPARQL queries, this paper investigates and reviews existing methods in which LD can be accessed using various tools and techniques, including query builders, visualisation approaches, and several LD applications. We then identify gaps within the literature and highlight future research directions