Abstract: This paper proposed an approach to creating an ontology-based natural language interface to relational databases which allows end-users to access and query information in database with a natural language. In order to strengthen the reliability and the user-friendliness of the system, our approach integrates WordNet as the base lexicon and ontology as the knowledge base of the semantic interpreter. The user inputs will be first translated into a syntax tree by syntax analysis and parsing, then it will be translated into an intermediate expression language DRS by the ontology-based semantic interpreter. The SQL generator transfers DRS expressions into SQL sentences by a template technictue. The DBMS executes SQL sentences and returns the final result.This paper presented the framework based on ontology technictues to implement portable NLIDBs that makes it easier to migrate from one domain to another. The prototype system and our experiments show that our approach has generated good results with excellent performance on common queries.

Key words: Ontology, NLIDBs, DRS, DBMS, SQL, OWL