Re: Can FK be nullable/optional by design?

"Bob Badour" <bbadour_at_golden.net> wrote in message news:tPGdndKS74g91Eei4p2dnA_at_golden.net...
> Chris Date's _Introduction to Database Management Systems_ makes a good
> start at them. I would seem foolish to try to teach them in an email
> message.

Don't worry Bob, I wasn't expecting you to seem foolish, or give a full tutorial.

> One would start with "What is data?" and "What does it mean to manage
data?"
> From there, one would move to: "What principles facilitate or guide
> effective data management?" And onward...

Ok, this makes sense.

> Since you apparently think one can easily enumerate them in an email, what
> would you describe as the fundamentals?

I hadn't even considered whether it was difficult or not. I was simply interested in what your perceived "fundamentals" entailed, mainly so I could go and learn more... I kind of expected you to mention some general topics, which may or may not have included:

Normalization - learning how to extrapolate to 1st, 2nd and 3rd normal form schemas
Integrety - learning that integrety applies at various levels - Domain, Column, Table, Database (Referential)
Data Types - seen as sets of permissable values that enforce business rules by constraining the data that is stored. Top-Down Analysis - learning to identify entities and business rules by reading existing documentation, verbal communication etc Bottom Up Analysis - learning to derive and normalise attribute listings Keys and Identity - different types and why Received on Tue Dec 16 2003 - 23:05:58 CET