Thanks Tom.
I'm not sure how an explicit null can be being specified but it sounds
like a plausible explanation. Now off to battle with VB;-(
Cheers,
Stephen Davies
On Fri, 23 Mar 2001 22:33:47 -0500, Tom Lane said:
> Stephen Davies <scldad@sdc.com.au> writes:
> > That is, how can a field that is defined as having a default value wind
> > up in the database as null.
>
> Via an explicit specification of a NULL field value in an INSERT.
> A default value does not override an explicit specification.
>
> > Despite the usual rules regarding null processing, I would still expect
> > a second unique primary key value of null to be rejected.
>
> If you had actually declared it as a primary key (which implies NOT
> NULL) then even one null would be disallowed. However a unique
> constraint without NOT NULL does not disallow nulls, even multiple ones.
> There's been some discussion about whether that's the correct behavior,
> but that's how it works at the moment.
>
> regards, tom lane
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