From: Michael A Nachbaur <mike@nachbaur.com>
To: Markus Bertheau <twanger@bluetwanger.de>
Cc: PGSQL-SQL <pgsql-sql@postgresql.org>
Subject: Re: multi-table unique index
Date: Mon, 23 Jun 2003 11:34:11 -0700
Message-ID: <200306231134.11430.mike@nachbaur.com> (raw)
In-Reply-To: <1056392214.3405.0.camel@saphir>
References: <1056376700.2037.2.camel@fluor>
<200306231032.56257.mike@nachbaur.com>
<1056392214.3405.0.camel@saphir>
On Monday 23 June 2003 11:16 am, Markus Bertheau wrote:
> В Пнд, 23.06.2003, в 19:32, Michael A Nachbaur пишет:
> > Instead of using the "serial" datatype, you can set it to "int4 PRIMARY
> > KEY DEFAULT nextval(foo_type_id_seq)" and you can manually create the
> > sequence "foo_type_id_seq".
> >
> > This way all the tables share the same sequence.
>
> Yeah, but I want to force this behaviour. so that it cannot happen by
> accident when you insert records without relying on the sequence.
I believe that's what I recommended. IIRC the "serial" datatype is simply a
shortcut to what I listed above. This way, if you do not explicitly specify
an id for your record, it'll pull the default; which retrieves a new values
from the sequence.
If you want to ensure that a value is unique when a record is inserted, even
if the user explicitly specifies an ID values, you can create a unique
trigger on the tables, but this depends on what you want to do.
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To: pgsql-sql@postgresql.org
Cc: mike@nachbaur.com, twanger@bluetwanger.de
Subject: Re: multi-table unique index
In-Reply-To: <200306231134.11430.mike@nachbaur.com>
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