Re: [SQL] ARRAY() returning NULL instead of ARRAY[]

Is this a TODO item?

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Markus Bertheau ? wrote:
> ? ???, 06/06/2005 ? 08:58 -0700, Joe Conway ?????:
> > Joe Conway wrote:
> > > Actually, consistent with my last post, I think array_upper() on a
> > > zero-element array should return NULL. A zero-element array has a
> > > defined lower bound, but its upper bound is not zero -- it is really
> > > undefined.
> >
> > Just to clarify my response, this is what I propose:
> >
> > regression=# select array_upper('[2][1:]={{},{}}'::int[],1);
> > array_upper
> > -------------
> > 2
> > (1 row)
> >
> > regression=# select array_upper('[2][1:]={{},{}}'::int[],2) IS NULL;
> > ?column?
> > ----------
> > t
> > (1 row)
>
> Hmm, this gets really complicated and inconsistent. Complicated means
> unusable. What about modifying the dimension syntax such that the second
> number means number of elements instead of upper bound? That particular
> problem would go away then, and array_upper('[0:0]={}'::int[]) can
> return the correct 0 then.
>
> What I'm actually worrying about is that array_upper(array(select 1
> where false)) returns 0.
>
> An option would be to drop the possibility to let the array start at
> another index than 0. I don't know why it was decided to do that in the
> first place. It seems a rather odd feature to me.
>
> Markus
> --
> Markus Bertheau ? <twanger(at)bluetwanger(dot)de>
>
>
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