Re: Split-up ECPG patches

Tom Lane írta:
> Boszormenyi Zoltan <zb(at)cybertec(dot)at> writes:
>
>> Tom Lane írta:
>>
>>> I'd look at requiring from_in as being the least-bad alternative.
>>>
>
>
>> Hm. "FETCH FORWARD variable" can only be a rowcount var
>> only if there's something afterwards, no? With the proposed
>> change in fetch_direction (moving FORWARD and BACKWARD
>> without the rowcount upper to the parent rules) now the parser is
>> able to look behind "FORWARD variable"...
>>
>
> The fundamental reason that there's a problem here is that ecpg has
> decided to accept a syntax that the backend doesn't (ie, FETCH with a
> fetch direction but no FROM/IN). I think that that's basically a bad
> idea: it's not helpful to users to be inconsistent, and it requires ugly
> hacks in ecpg, and now ugly hacks in the core grammar as well. We
> should resolve it either by taking out that syntax from ecpg, or by
> making the backend accept it too. Not by uglifying the grammars some
> more in order to keep them inconsistent.
>
> If we were going to allow it in the core, I think moving the cursor
> name into the fetch_direction production might work, ie, change
> fetch_direction to fetch_args and make it cover everything that
> FETCH and MOVE share. Probably from_in could become opt_from_in,
> since the alternatives for it are fully reserved words already, and we
> wouldn't need to double up any of the fetch_direction productions.
>

And maybe, possibly with this change as a start, someday
we can support dynamic cursorname in plain SQL, too.
DECLARE $1 CURSOR FOR SELECT ...
It would be a much cleaner solution in ECPG, too.

Best regards,
Zoltán Böszörményi

--
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Zoltán Böszörményi
Cybertec Schönig & Schönig GmbH
http://www.postgresql.at/