When I was in school I wanted to know why I had to learn something: Why learn about history? It’s about a bunch of dead people, often from far away. I would also ask: Why would I ever learn English. . .
I feel that the computer industry does not only forget about history but is quick to discard what has been done before. Just remember when object databases came out, the trade magazines where trumpeting the death of relational databases.
There is a disconnect between the object-oriented (OO) approach and the use of relational databases. This will be the subject of the next few entries. Lets start with an example:
An object person will look at the employees of a company and see managers, full-time employees, part-time employees and contractors. This will lead to the following model:
With the definition of the multiple types of employees, we can easily see that they will want multiple tables, one per defined object. Of course, for a database person, we see something like:
CREATE TABLE employee (
Empno int PRIMARY KEY,
mgrNo int ,
. . .
As you can see, we can already see that a "data access expert" can start some discussions with the OO architects and programmers.Don’t get me wrong. I like OO. I think it is a wonderful approach but just like anything it can be abused. See what you think of:http://csis.pace.edu/~bergin/patterns/ppoop.html