Обсуждение: VIEWS

Dear Sirs

I encountered a minor Postgres problem using VIEW:

Creating a View like
CREATE VIEW SELECT * FROM table1
works perfecly

As soon as we enlarge table1 by new Attributes, they will not show up in the
VIEV
The VIEW will need to be deleted and recreated.

This behaviuor may not be considered to be a Bug but it is annoying and it
conflicts with the
assumption, that a VIEW does not execute any operation on a Database.

Thanks for listening to my input.

Prologon AG
M. Feier
mfeier@prologon.ch

On Wed, 22 Sep 2004, Markus Feier wrote:

> Dear Sirs
>
> I encountered a minor Postgres problem using VIEW:
>
> Creating a View like
> CREATE VIEW SELECT * FROM table1
> works perfecly
>
> As soon as we enlarge table1 by new Attributes, they will not show up in the
> VIEV
> The VIEW will need to be deleted and recreated.
>
> This behaviuor may not be considered to be a Bug but it is annoying and
> it conflicts with the assumption, that a VIEW does not execute any
> operation on a Database.

AFAICS, this is what the spec says to do in any case.  The view descriptor
for the view at create time includes column descriptors taken from the
query expression.

From SQL92 11.11 <add column definition>
            Note: The addition of a column to a table has no effect on any
            existing <query expression> included in a view descriptor or
            <search condition> included in constraint descriptor because
            any implicit <column reference>s in these clauses are replaced
            by explicit <column reference>s when the clause is originally
            evaluated. See the Syntax Rules of Subclause 7.10, "<query ex-
            pression>".