Date: Thu, 7 Oct 2021 17:18:49 -0300
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
To: rir <rirans@comcast.net>
Cc: Laurenz Albe <laurenz.albe@cybertec.at>,
	pgsql-docs@lists.postgresql.org
Subject: Re: small patch
Message-ID: <202110072018.yugknob35ubc@alvherre.pgsql>
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On 2021-Oct-07, rir wrote:

> For myself,
>    'FETCH [ <direction> [ FROM | IN ] ] <cursor_name>'
> clearly indicates that 'direction' is optional.

Hmm, aren't you misreading the scope of the outer square brackets?  If
<direction> is optional independently of [FROM|IN], then the synopsis
should be

FETCH [ <direction> ] [ FROM | IN ] <cursor_name>

and I think that's correct, since all forms omitting any of these are
accepted:

alvherre=# begin;
BEGIN
alvherre=*# declare c scroll cursor with hold for select 1 ;
DECLARE CURSOR
alvherre=*# commit;
COMMIT
alvherre=# fetch forward from c;
 ?column? 
----------
        1
(1 fila)

alvherre=# fetch from c;
 ?column? 
----------
(0 filas)

alvherre=# fetch BACKWARD c;
 ?column? 
----------
        1
(1 fila)

alvherre=# fetch c;
 ?column? 
----------
(0 filas)


-- 
Álvaro Herrera           39°49'30"S 73°17'W  —  https://www.EnterpriseDB.com/