Re: sql tables

From: Roy Hann <specially_at_processed.almost.meat>
Date: Thu, 11 Oct 2007 17:29:35 +0100
Message-ID: <ds2dnQF3Rrfm0pPaRVnyigA@pipex.net>

"David Cressey" <cressey73_at_verizon.net> wrote in message news:2RrPi.10966$br2.10003_at_trndny03...

>

> All of the "major" SQL DBMS products permit storing more than one
> identical
> row in a table. However, they provide several ways the database manager
> can
> protect the database from that event. The simplest is to declare a
> primary
> key for the table.

Sadly given that it is now considered "best practice" to blindly and automatically attach an entirely spurious unique "primary key" value to every row in a table, that would be entirely futile.

> This will also, however, protect against inserting two
> rows that differ, but have identical primary key values. Most often,
> that
> coincides with the intent of the manager.

I wonder if you can be that confident about what goes on inside the head of the average (database) manager?

Roy Received on Thu Oct 11 2007 - 11:29:35 CDT