Re: foreign key constraint versus referential integrity constraint

Mr. Scott wrote:
> ...
> Tables house data; views just present it. That is in a nutshell the
> difference between tables and views. What is presented by a view implies
> what is in the operands of the view's definition. As a consequence, in
> order to be fully updatable and therefore interchangable, each and every set
> of inserts, updates and deletes applied to a view must map one-to-one to a
> set of inserts, updates and deletes applied to those operands. Views that
> are joins or unions or restrictions or projections in general aren't fully
> updatable. There are exceptions, of course. A view defined on a pair of
> tables that participate in mutual foreign keys is fully updatable because
> each and every set of inserts, updates and deletes applied to the view maps
> one-to-one to a set of inserts, updates and deletes applied to the tables.
> ...

Doesn't this amount to saying that tables are stored and views are not?   (whereas I don't see why a view couldn't be stored because of some practical reason or other.) Received on Thu Oct 29 2009 - 00:51:57 CET