Re: same sequence as primary key in more than one table
From: ddf <oratune_at_msn.com>
Date: Mon, 15 Jun 2009 06:38:04 -0700 (PDT)
Message-ID: <bc7332bc-6a37-4d2f-8fdc-07fe1be0e40a_at_a5g2000pre.googlegroups.com>
On Jun 15, 6:02 am, Shakespeare <what..._at_xs4all.nl> wrote:
> student4life schreef:
>
> > Hello,
>
> > For example, I have 'sellers' and 'buyers' both need to authenticate
> > from a database table 'users' with sequence as primary key which is
> > also as primary key in tables 'sellers' and 'buyers' (both have one-to-
> > one relationship with 'users') but I am not sure whether it's good
> > practice to have sequence number jumping alternatively between tables.
> > Could someone inform me what the best practice/design is under the
> > scenario? TIA
>
> As long as sequences and there values don't have a significant meaning,
> there is no problem with using the same sequence for different tables.
> It's a matter of taste and standards. Some standards require a separate
> sequence for each table, some standards don't.
>
> I wonder though: is the primary key in 'sellers' the same value as the
> primary key in 'users', so if a seller has, let's say, 1676 as primary
> key, is the primary key value in 'users' 1676 as well?
>
> Shakespeare
Date: Mon, 15 Jun 2009 06:38:04 -0700 (PDT)
Message-ID: <bc7332bc-6a37-4d2f-8fdc-07fe1be0e40a_at_a5g2000pre.googlegroups.com>
On Jun 15, 6:02 am, Shakespeare <what..._at_xs4all.nl> wrote:
> student4life schreef:
>
> > Hello,
>
> > For example, I have 'sellers' and 'buyers' both need to authenticate
> > from a database table 'users' with sequence as primary key which is
> > also as primary key in tables 'sellers' and 'buyers' (both have one-to-
> > one relationship with 'users') but I am not sure whether it's good
> > practice to have sequence number jumping alternatively between tables.
> > Could someone inform me what the best practice/design is under the
> > scenario? TIA
>
> As long as sequences and there values don't have a significant meaning,
> there is no problem with using the same sequence for different tables.
> It's a matter of taste and standards. Some standards require a separate
> sequence for each table, some standards don't.
>
> I wonder though: is the primary key in 'sellers' the same value as the
> primary key in 'users', so if a seller has, let's say, 1676 as primary
> key, is the primary key value in 'users' 1676 as well?
>
> Shakespeare
Presuming the columns are populated by triggers the same key value cannot be generated for two tables from the same sequence since the trigger must call sequence_name.nextval to consistently return a value successfully.
David Fitzjarrell Received on Mon Jun 15 2009 - 08:38:04 CDT