Abstract
Knowledge representation is considered one of the main challenges in knowledge-based system. Currently, knowledge graph is the most modern knowledge representation model, which has been utilized in critical knowledge based systems. On the other hand, the Entity Relationship Diagram (ERD) for relational database is the most used model in information systems. In this paper, an efficient approach for mapping ERD to knowledge graph is presented with a case study for demonstrating the mapping process. First, relational tables have been represented by knowledge graph, then reification has been implemented to convert the knowledge graph to knowledge base. Eventually, extracting knowledge from these knowledge bases is processed by Prolog. Our proposed model has been empirically evaluated by comparing the Prolog results with the conventional SQL results.