Message-Id: <362DD338.9E52E89B@insightdist.com>
Date: Wed, 21 Oct 1998 08:27:36 -0400
From: David Hartwig <daveh@insightdist.com>
Organization: Insight Distribution Systems
Mime-Version: 1.0
To: Colin McKinnon <colin@wew.co.uk>
Cc: pgsql-interfaces@hub.org
Subject: Re: [INTERFACES] Re: using indexes with the OR clause
References: <3.0.5.32.19981021084851.007ab620@lonmay>
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Colin McKinnon wrote:

> Hello all,
> I'm a newbie to postgres (haven't got as far as setting up odbc on my
> system yet) so please forgive me if I'm talking ^&*%.
>
> At 23:00 20/10/98 -0400, you wrote:
> >Date: Tue, 20 Oct 1998 15:52:06 +0200
> >From: Sferacarta Software <sferac@bo.nettuno.it>
> >Subject: using indexes with the OR clause
> >
> >Hi all,
> >
> >I'm trying v6.4beta2 via ODBC-Access.
> >
> >I have the following table:
> >
> >CREATE TABLE attivita (
> >        azienda                 CHAR(11) NOT NULL,
> >        attivita                CHAR(03) NOT NULL,
> >        specifica               CHAR(02),
> >        cod_alternativo         CHAR(10),
> >        conto_economico         CHAR(02),
> >        inizio_attivita         DATE,
> >        fine_attivita           DATE,
> >        PRIMARY KEY (azienda,attivita,specifica,inizio_attivita)
> >        );
> >
> >I linked this table on M$-Access specifying the Access-key equal to
> >PostgreSQL PRIMARY KEY to test indexes with the OR clause but
> >I have the following error message:
> <snip>
> It may be nothing to do with your error but I see from your code you allow
> NULL values as part of the primary key. The programming style is
> questionable, but Access is VERY particular about not having NULL values in
> JET tables so I suppose it could be the same for linked tables.
>
> I would try declaring each attribute of the primary key as NOT NULL.
>

In PostgreSQL the PRIMARY KEY clause forces an implied NOT NULL on each
specified column.