Handling Three-Value Logic

I have just finished reading Applied Mathematics for Database Professionals By Lex de Haan and Toon Koppelaars. I was struck by the discussion about nulls in Appendix D, especially about the inconsistent handling of NULLs between constraints and predicates in SQL (see p.344)

Continue reading


NORDIC Schema for TopLink Demonstration (4)

Having discovered the limitations of JDeveloper for support of object-oriented database objects in NORDIC Schema for TopLink Demonstration (3), we will clean up the NORDIC schema in both the offline and online databases, before exploring TopLink itself.

Continue reading

NORDIC Schema for TopLink Demonstration (1)


This document details the SQL needed to establish the NORDIC schema in an Oracle XE database for the demonstration of the use of TopLink which is included in Oracle JDeveloper 11g (Build 5188). This SQL is based on the NORDIC series of articles on this blog.

Object views are used to replace object tables because TopLink cannot import Object Tables into the Offline database.
Continue reading