Message-ID: <4721DECF.80401@4js.com>
Date: Fri, 26 Oct 2007 14:34:23 +0200
From: Sebastien FLAESCH <sf@4js.com>
Organization: Four J's Development Tools
User-Agent: Thunderbird 1.5.0.9 (X11/20061220)
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To: Heikki Linnakangas <heikki@enterprisedb.com>
CC: pgsql-hackers@postgresql.org, Guillaume ERGAND <ger@4js.com>
Subject: Re: PostgreSQL 8.3, libpq and WHERE CURRENT OF
References: <4721BAFE.3080601@4js.com> <4721BF34.80901@enterprisedb.com>
In-Reply-To: <4721BF34.80901@enterprisedb.com>
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Thanks Heikki for this quick answer.

Actually we do the following lipq calls:

- PQPrepare(... "SELECT ... FROM ... FOR UPDATE" ... )
- PQexecPrepared(...)
- PQntuples(...) / PQgetvalue(...)

i.e. we don't use the DECLARE CURSOR instruction, we just prepare/execute
the plain SELECT statement (with potential parameters)...

I can't remember why but there was some limitation or problems to use the
DECLARE CURSOR in our context... must dig in my mail archive to give you
more details...

FYI we do actually a PostgreSQL driver for our runtime VM...

Does a simple PQPrepare() with a SELECT statement not create a cursor on
the server side? If yes, would it not be possible to pass a cursor name
as in ODBC?

Best regards,
Seb

Heikki Linnakangas wrote:
> Sebastien FLAESCH wrote:
>> Just looked at the new features of 8.3 and realized that positioned
>> updates/deletes is now possible with this new release...
>>
>> We would use that if we could define the cursor name with a libpq function.
> 
> I don't understand. When you open a cursor with DECLARE CURSOR, you give
> it a name. Doesn't that do what you want?
>