Database-to-Ontology Mapping Generation for Semantic Interoperability

Database-to-Ontology Mapping Generation for Semantic Interoperability Raji Ghawi and Nadine Cullot Laboratoire Electronique, Informatique et Image UMR CNRS 5158 Université de Bourgogne, Dijon, FRANCE {raji.ghawi , nadine.cullot}@u-bourgogne.fr

Outlines

Introduction

OWSCIS Architecture

DB2OWL

Mapping process

Future Works

Introduction

Interoperability Problem

Distrubtion

Hetereogeniety

Instability

Solutions

Ontologies

Web Services

OWSCIS O ntology and W eb S ervices based C ooperation of I nformation S ources

Hybrid Ontology Approach

Local Ontologies and Reference Ontology

Web Service - Oriented Architecture

Automatic Mappings

Inter-Ontology Mapping

Database-to-Ontology Mapping

OWSCIS Architecture Mapping Web Service Visualisation Web Service Query Decomposition Query Recomposition Query Web Service Data Provider Data Provider Mapping Directory Reference Ontology Tool Box Knowledge Base Module DB2OWL Database Data Provider Local Ontology End User Single Query Resolution Mappings Local Onto  Ref. Onto DB  Local Onto Expert

Database to Ontology mapping

Correspondences between database components (table, column, constraint) and ontological components (concept, property).

Database to ontology mapping Complex Direct Data migration Query Driven Massive Dump Mapping database to already existing ontology Creating ontology from database Mapping definition Mapping definition

DB2OWL

Generate a local ontology from a relational database

OWL-DL

Generate Mapping document

Full automatic process

Mapping Process in DB2OWL

Example Database schema

Table’s particular cases

Mapping process

Example Database Schema PRESENCE StudentID SessionID DIPLOMA DiplomaID DiplomaName PERSON PersonID FirstName LastName HALL HallID HallName Building STUDENT StudentID StudentNumber DiplomaID LECTURER LecturerID LecturerR oom SESSION SessionID ModulID LecturerID HallID Time DiplomaID MODULE ModuleID ModuleName Primary key Foreign key

Table’s particular cases : Case 1

A table T is used only to relate two other tables T1, T2 in a many-to-many relationship,

all T columns are foreign and primary keys

PRESENCE StudentID SessionID STUDENT StudentID StudentNumber DiplomaID SESSION SessionID ModulID LecturerID HallID Time

A table T is related to another table T1 by a referential integrity constraint whose local attributes are also the primary keys.

In this case all the primary keys of T are foreign keys

PERSON PersonID FirstName LastName STUDENT StudentID StudentNumber DiplomaID

The default case

Occurs when none of previous cases occurs

T is not in case1 nor in case2

DIPLOMA DiplomaID DiplomaName

Mapping Process - 1

The database tables that are in case 3 are mapped to OWL classes

DIPLOMA DiplomaID DiplomaName PERSON PersonID FirstName LastName HALL HallID HallName Building SESSION SessionID ModulID LecturerID HallID Time DiplomaID MODULE ModuleID ModuleName Database PERSON DIPLOMA HALL MODULE SESSION Ontology

Mapping Process - 2

The tables in case 2 are mapped to subclasses of those classes corresponding to their related tables

PERSON PersonID FirstName LastName Database STUDENT StudentID StudentNumber DiplomaID LECTURER LecturerID LecturerR oom is_a PERSON DIPLOMA HALL MODULE SESSION Ontology LECTURER STUDENT

Mapping Process - 3

The tables in case 1 are not mapped to classes, but we add two object properties, one for each class that its corresponding table was related to the current table

Database STUDENT StudentID StudentNumber DiplomaID is_a SESSION SessionID ModulID LecturerID HallID Time PRESENCE StudentID SessionID Object Property PERSON DIPLOMA HALL MODULE SESSION Ontology LECTURER STUDENT

Mapping Process - 4

For the tables in case 3, we map their referential constraints to object properties whose ranges will be the classes corresponding to their related tables

Database DIPLOMA DiplomaID DiplomaName HALL HallID HallName Building SESSION SessionID ModulID LecturerID HallID Time DiplomaID MODULE ModuleID ModuleName LECTURER LecturerID LecturerR oom PERSON DIPLOMA HALL MODULE SESSION Ontology LECTURER STUDENT is_a Object Property

Mapping Process - 5

For tables that are in case 2 and have other referential constraints than this used to create the subclass, we map them to object properties as we done in the previous step

Database DIPLOMA DiplomaID DiplomaName STUDENT StudentID StudentNumber DiplomaID PERSON DIPLOMA HALL MODULE SESSION Ontology LECTURER STUDENT is_a Object Property

Mapping Process - 6

For all tables, non-key columns are mapped to datatype properties.

The range of a datatype property is the XSD equivalent to the data type of its original column.

is_a Object Property Ontology DIPLOMA DiplomaId DiplomaName Hall HallId HallName Building MODULE ModuleId ModuleName SESSION SessionID Time PERSON PersonId FirstName LastName LECTURER LecturerRoom STUDENT StudentNumber Datatype Property

DB2OWL - Implementation Database DB Model tables constraints Ontology Model classes OWL Ontology JDBC Jena Mapping algorithm Mapping document Mapping Model

Future work