Re: update from select

On Wednesday 29 Oct 2003 2:58 pm, Stephan Szabo wrote:
> On Wed, 29 Oct 2003, Gary Stainburn wrote:
> > Hi folks,
> >
> > don't know if it's cos of the 17 hours I've just worked (sympathy vote
> > please) but I can't get this one worked out
> >
> > I've got table names with nid as name id field and nallowfollow flag.
> > I've got a vehicles table with vowner pointing at nid and a vallowfollow
> > field.
> >
> > How can I update nallowfollow from the appropriate vallowfollow flag?
>
> If vehicles.vowner is unique, something like this maybe (using extensions
> to sql)?
> update names set nallowfollow=vehicles.vallowfollow
> from vehicles where vehicles.vowner=names.nid;
>
> I think it'd be the follwoing in straight sql:
> update names set nallowfollow=
> (select vallowfollow from vehicles where vehicles.vowner=names.nid);
>
>
> If it's not unique, what do you do if there are two vehicles with the same
> vowner and different values for vallowfollow?

Thanks for this Stephan,

although the vowner is not unique, the update has worked sufficantly.

Gary

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Gary Stainburn

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