Re: sql tables
Date: Thu, 11 Oct 2007 19:35:10 GMT
"Roy Hann" <specially_at_processed.almost.meat> wrote in message
> "David Cressey" <cressey73_at_verizon.net> wrote in message
> > 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.
Why is is sad? What's wrong with declaring a primary key? Or do mean
something else by "attach"?
> > 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
> the average (database) manager?
Received on Thu Oct 11 2007 - 21:35:10 CEST