Re: Entity and Relationship - the same thing ?

> Date. I recommend this book with a caveat. It relies on what Date calls
> "Tutorial D". This is a non existant language (non existant in the sense
> that no computer can run it) that is used for many of the examples.

Actually there is an implementation of the language by a company, Alphora, whose
product Dataphor uses a language called D4. D4 is based on Tutorial D. In fact
I am using it right now...

create table Genesis {
 ID:System.Integer,
 key {}
} ;

create table MarkdownActivities {
 ID:System.Integer,
 key {ID},
 reference MarkdownActivities.ID {} references Genesis {} } ;

Genesis := Genesis union table { row { 1 as ID } } ;

MarkdownActivities := MarkdownActivities union table { row { 5 as ID } } ;

Look at that! An empty key!! Wonderfull, truly wonderfull! Relational assignment , HOORAY!!!!!

-spencer Received on Tue May 07 2002 - 19:49:47 CEST