[vox-tech] SQL selecting distinct from multiple index tables
Jeff Newmiller
vox-tech@lists.lugod.org
Fri, 30 Jan 2004 22:04:39 -0800 (PST)
On Fri, 30 Jan 2004, Mitch Patenaude wrote:
> select distinct O.OID, O.Name, O.Acronym
> from Organizations O, OrgDocs D, OrgProjects P
> where D.OrgID = O.OID or P.OrgID = O.OID
>
> I think this will result in two full table scans though......
Actually, it will probably result in Count(P.*) passes through P...
very inefficient.
I think you were on the right track originally ... probably dump the
results of both queries to a temporary table and retrieve distinct rows.
>
> -- Mitch
>
> On Friday, Jan 30, 2004, at 21:24 US/Pacific, David Siedband wrote:
>
> > I have two index tables the associate Organizations with documents and
> > projects. I'm trying to write a query that returns all the
> > organizations that are associated with either a project or document.
> >
> > To select distinct organization that are either associated with a
> > Document or a Project, I'm using SQL that looks like this.
> >
> > select distinct Organizations.OID , Organizations.Name ,
> > Organizations.Acronym
> > from OrgDocs , Organizations
> > where OrgDocs.OrgID = Organizations.OID
> >
> > select distinct Organizations.OID , Organizations.Name ,
> > Organizations.Acronym
> > from OrgProjects , Organizations
> > where OrgProjects.OrgID = Organizations.OID
> >
> > Any suggestions on how to combine this into a single query?
> >
> > thx,
> >
> > --
> > David
> >
> >
> >
> >
> >
> >
> > _______________________________________________
> > vox-tech mailing list
> > vox-tech@lists.lugod.org
> > http://lists.lugod.org/mailman/listinfo/vox-tech
> >
>
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