Re: Thoughts about updateable views

On Mon, 22 Mar 2004, Bernd Helmle wrote:

> I am currently thinking of updateable views for a possible student research
> project. In this
> case there comes some points to my mind, i want to share with the list.
>
> a) Definition of an updateable view?

The SQL spec. You should definately get a look at at least the SQL92
definition before proceeding.

> b) The creation of an automatic INSERT/UPDATE or DELETE Rule had to be done
> with
> the creation of the SELECT Rule. I understand how PostgreSQL handles views
> with its Rule
> System, but what happens when no appropiate Rule can be created? Reject the

CREATE VIEW needs to check if all columns in the target list and the base
table are updatable or insertable into. Eg: How can you update: select
foo, random() from bar?

If the user specifically asked for an updatable view, then they can't have
one. If they didn't specifically ask, they get the usual read only view.

Gavin