LODQL: A Language for Creation, Query, and Service Generation of Linked Open Data

Abstract

Nowadays, open data has become more and more popular and is widely used in a variety of service domains. However, in Taiwan, most open datasets are still separate while linked open data (LOD) is still lacking. Without LOD, application developers are difficult to locate and combine appropriate open datasets to create innovative applications. Therefore, to facilitate the consumption and the spreading of open data in Taiwan, we propose a new data query language, referred to as LODQL (Linked Open Data Query Language), to allow the definition of rules for building LOD by data experts and the consumption of LOD via RESTful services by application developers. We designed the LODE (LODQL Engine) to parse the LODQL, build LOD in RDF (Resource Description Framework) according to LODQL, and generate the corresponding RESTful services that extract required LOD based on the user query. LODE is also able to perform data visualization to show relevance of open datasets and relations between open data items. The developed system implementation and the evaluation experiments fully demonstrate that the feasibility and effectiveness of LODQL and LODE.