Thread: update from select

update from select

From
Gary Stainburn
Date:
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?
-- 
Gary Stainburn
This email does not contain private or confidential material as it
may be snooped on by interested government parties for unknown
and undisclosed purposes - Regulation of Investigatory Powers Act, 2000     



Re: update from select

From
Stephan Szabo
Date:
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.vallowfollowfrom 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?


Re: update from select

From
Gary Stainburn
Date:
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
This email does not contain private or confidential material as it
may be snooped on by interested government parties for unknown
and undisclosed purposes - Regulation of Investigatory Powers Act, 2000