Re: the parsing of parameters

On Fri, May 10, 2002 at 11:17:39AM -0400, Tom Lane wrote:
> Jan Wieck <janwieck(at)yahoo(dot)com> writes:
> > Tom Lane wrote:
> >> For this particular application, at least, I do not see the value ...
> >> in fact this seems more likely to break stuff than help. If the
> >> application does not know what the datatypes are supposed to be,
> >> how is it going to call the prepared statement?
>
> > Right now using UNKNOWN_OID in that place leads to a parse
> > error, what makes me feel absolutely comfortable that there
> > will be nobody using it today. So what kind of "break" are
> > you talking about?
>
> What I mean is that I don't see how an application is going to use
> PREPARE/EXECUTE without knowing the data types of the values it
> has to send for EXECUTE. Inside SPI you could maybe do it, since
> the calling code can examine the modified argtype array, but there
> is no such back-communication channel for PREPARE. This holds
> for both textual and binary kinds of EXECUTE: how do you know what
> you are supposed to send?

In my original PREPARE/EXECUTE patch (it works in 7.1):

PREPARE name AS select * from tab where data=$1 USING text;
EXECUTE name USING 'nice text data';

IMHO is possible think about

EXECUTE name USING 'nice text'::text;

or other cast methods.

Karel

--
Karel Zak <zakkr(at)zf(dot)jcu(dot)cz>
http://home.zf.jcu.cz/~zakkr/

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