Re: [HACKERS] [SQL] ARRAY() returning NULL instead of ARRAY[] resp. {}

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Re: [HACKERS] [SQL] ARRAY() returning NULL instead of ARRAY[] resp. {}

Markus Bertheau
Dnia 24-05-2005, wto o godzinie 00:06 -0400, Tom Lane napisał(a):

> Joe Conway <[hidden email]> writes:
> > Markus Bertheau wrote:
> >> why does SELECT ARRAY(SELECT 1 WHERE FALSE) return NULL instead of
> >> ARRAY[] resp. '{}'?
>
> > Why would you expect an empty array instead of a NULL?
>
> I think he's got a good point, actually.  We document the ARRAY-with-
> parens-around-a-SELECT syntax as
>
> The resulting one-dimensional array will have an element for
> each row in the subquery result, with an element type matching
> that of the subquery's output column.
>
> To me, that implies that a subquery result of no rows generates a
> one-dimensional array of no elements, not a null array.
>
> The point Markus is complaining about seems like it should
> be easily fixable.
Great. Does this belong on the TODO?

--
Markus Bertheau <[hidden email]>

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