>At 12:26 PM 06-03-02 +1300, Sandeep wrote:
> >Why isn't the following allowed ?
> >
> >create table test (
> >number integer default gen_id (gen_test, 1),
> >age integer check (age > 20),
> >name varchar (20))

The real answer is that generators were added after the
code that handled defaults. That's probably a good idea
for a feature.

At 03:35 PM 3/6/2002 +1100, Helen Borrie wrote:

>create table test1 (
>number integer computed by (gen_id (gen_test, 1)),
>age integer check (age > 20),
>name varchar (20))

That's going to give you a different value for number
every time the record is read. Remember, computed fields
are computed on reference.

As for computed and not null, that's a reasonable restriction.
There's no way to do a meaningful null test on a computed field.

The null state of a computed field may depend on values outside
the table - you could easily make the field null without touching
the record. Then the next time you tried to modify the record
you'd get an error.


Regards,

Ann
www.ibphoenix.com
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