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Commits

  1. Test and document the behavior of initialization cross-refs in plpgsql.

  1. plpgsql: can I use a variable in a DECLARE later whithin the DECLARE?

    tomas@tuxteam.de — 2021-10-29T12:14:35Z

    Hi,

In plpgsql, i'm trying to use a variable initialised in a DECLARE in
a later initialisation expression whithin the same DECLARE:

  DECLARE
    x int := 23;
    y int := x + 4
  BEGIN
   ...

Experiments suggest that it works, but the docs are silent about that.
Is this a good idea, or should I be more careful and do it in a nested
block?

(For Lispers: is that a let, or a let*? ;-)

Thanks & cheers
 - tomás

  2. Re: plpgsql: can I use a variable in a DECLARE later whithin the DECLARE?

    Tom Lane <tgl@sss.pgh.pa.us> — 2021-10-29T14:04:31Z

    <tomas@tuxteam.de> writes:
> In plpgsql, i'm trying to use a variable initialised in a DECLARE in
> a later initialisation expression whithin the same DECLARE:

>   DECLARE
>     x int := 23;
>     y int := x + 4
>   BEGIN
>    ...

> Experiments suggest that it works, but the docs are silent about that.
> Is this a good idea, or should I be more careful and do it in a nested
> block?

I don't see any reason to foresee that it would break.

However, I notice that we don't actually have any regression tests
checking this.  scope_test() in plpgsql.sql checks an adjacent
question, but not exactly this one.  I'm a bit inclined now to go
add such a test.

			regards, tom lane

  3. Re: plpgsql: can I use a variable in a DECLARE later whithin the DECLARE?

    tomas@tuxteam.de — 2021-10-29T14:50:30Z

    On Fri, Oct 29, 2021 at 10:04:31AM -0400, Tom Lane wrote:
> <tomas@tuxteam.de> writes:
> > In plpgsql, i'm trying to use a variable initialised in a DECLARE in
> > a later initialisation expression whithin the same DECLARE:
> 
> >   DECLARE
> >     x int := 23;
> >     y int := x + 4
> >   BEGIN
> >    ...
> 
> > Experiments suggest that it works, but the docs are silent about that.
> > Is this a good idea, or should I be more careful and do it in a nested
> > block?
> 
> I don't see any reason to foresee that it would break.

Thanks :)

> However, I notice that we don't actually have any regression tests
> checking this.  scope_test() in plpgsql.sql checks an adjacent
> question, but not exactly this one.  I'm a bit inclined now to go
> add such a test.

Even more thanks.

After a long hiatus I have the luck to play again with PostgreSQL.
Let me say: you folks rock, seriously.

Cheers
 - t