Re: libpq and prepared statements progress for 8.0 - Mailing list pgsql-hackers

From Oliver Jowett
Subject Re: libpq and prepared statements progress for 8.0
Date
Msg-id 414B8C0A.8000302@opencloud.com
Whole thread Raw
In response to Re: libpq and prepared statements progress for 8.0  (Tom Lane <tgl@sss.pgh.pa.us>)
Responses Re: libpq and prepared statements progress for 8.0  (Oliver Jowett <oliver@opencloud.com>)
List pgsql-hackers
Tom Lane wrote:
> David Wheeler <david@kineticode.com> writes:
> 
>>To get initial PREPARE support, I don't think that the other DBD::Pg 
>>developers mind sending strings to the PostgreSQL server in a SQL 
>>PREPARE statement.
> 
> 
>>The question, in my mind, is it currently possible to do this without 
>>specifying the type of every placeholder?
> 
> 
> Well, that's the problem: you can't.  The SQL PREPARE command doesn't
> have any provision for dealing with unspecified parameters.  I think
> this is reasonable since if it could, it would still have no way to tell
> you what it resolved the parameter types as.

But it sounds like the client doesn't care about the type info anyway; 
it'd pass all the parameters as text and let the backend sort out the 
types when doing implicit conversions in the EXECUTE parse step:

template1=> prepare s1(int) as select $1;
PREPARE
template1=> execute s1('12'); ?column?
----------       12
(1 row)

(now replace "int" with "unknown"..)

-O


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