Re: NULL and plpgsql rows

Is there a TODO here?

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Jim Nasby wrote:
> On Oct 2, 2006, at 6:28 PM, Tom Lane wrote:
> > "Jim C. Nasby" <jim(at)nasby(dot)net> writes:
> >> However, the test right above that means that we'll fail if the user
> >> tries something like "row_variable := NULL;":
> >
> > The patch you seem to have in mind would allow
> > row_variable := int_variable;
> > to succeed if the int_variable chanced to contain NULL, which is
> > surely
> > not very desirable.
>
> Hrm... is there any reasonable way to catch that?
>
> > The real issue here is that the bare NULL has type UNKNOWN and
> > we're not
> > making any effort to cast it. I'm not sure whether it'd work to
> > simply
> > apply exec_cast_value --- that looks like it's only meant to handle
> > scalars, where in general you'd need something close to
> > ExecEvalConvertRowtype().
> >
> >> Of course, setting a row variable to null is a lot more useful if
> >> we can
> >> actually test for it after the fact, and I'm not really sure how
> >> to make
> >> that happen.
> >
> > Doesn't IS NULL work (as of CVS HEAD)?
>
> Ahh, so it does. Doesn't work with RECORD, though... which seems a
> bit surprising. I can't really think of a good reason why they should
> differ.
>
> ERROR: record "v_row" is not assigned yet
> DETAIL: The tuple structure of a not-yet-assigned record is
> indeterminate.
> CONTEXT: PL/pgSQL function "test" line 4 at return
>
> --
> Jim Nasby jim(at)nasby(dot)net
> EnterpriseDB http://enterprisedb.com 512.569.9461 (cell)
>
>
>
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Bruce Momjian <bruce(at)momjian(dot)us> http://momjian.us
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