Closed javadch closed 1 year ago
write 3-4 items and itemise the number what we need to do, eg-table choosing, curate data, things which output is important.
Choice of mapping tool
With the advancement of the Knowledge graph, several approaches and tools came up to convert the relational database and unstructured data into RDF triples.
We have tested several tools which suit our requirement like r2rml-parser-master(https://github.com/nkons/r2rml-parser), Rocket RML (https://semantifyit.github.io/RocketRML/). Due to lack of proper documentation and ease of uses, we decided to use the SDM-RDFzier tool (https://github.com/SDM-TIB/SDM-RDFizer). The SDM-RDFizer, an interpreter of mapping rules that allows the transformation of (un)structured data into RDF knowledge graphs.
Learning R2RML language
To write a mapping file, we need to understand the syntax of the mapping language. Following the W3C standard, R2RML is well suited for our task. Detailed documentation is available at https://www.w3.org/TR/r2rml/
Autmotaing R2RML
Till now, there is no way to write the mapping rule automatically, we need to write the mapping rules manually. Covering each table and its properties is time-consuming so we also use Mapeathor (https://github.com/oeg-upm/Mapeathor). Mapeathor translates your mapping rules specified in spreadsheets to a mapping language.
dev of the following items will continue on #21
BD_table | Priority (10 is high) | short description | Foreign Keys
A nice tutorial for Knowledge Graph Construction Using Declarative Mapping Rules is also available at https://github.com/oeg-upm/kgc-tutorial-iswc2020
In this step, we map from multiple sources using the developed ontology. Then we generated an RDF file and store it as a knowledge graph.
A more description is given at https://github.com/TIBHannover/diaspora/issues/2