To: Gregory Stark <stark@enterprisedb.com>
cc: "Andrew McNamara" <andrewm@object-craft.com.au>,
	pgsql-interfaces@postgresql.org
Subject: Re: PQexecParams and IN query? 
In-reply-to: <87tzuj1qzk.fsf@oxford.xeocode.com> 
References: <20070511120332.6F61C5CC4B5@longblack.object-craft.com.au>
	<87tzuj1qzk.fsf@oxford.xeocode.com>
Comments: In-reply-to Gregory Stark <stark@enterprisedb.com>
	message dated "Fri, 11 May 2007 13:31:27 +0100"
Date: Fri, 11 May 2007 09:12:46 -0400
Message-ID: <17601.1178889166@sss.pgh.pa.us>
From: Tom Lane <tgl@sss.pgh.pa.us>

Gregory Stark <stark@enterprisedb.com> writes:
> "Andrew McNamara" <andrewm@object-craft.com.au> writes:
>> I'm trying to use PQexecParams to do an "IN" query, where the set of
>> values is supplied as a single parameter - essentially:
>> 
>> SELECT * FROM sometable WHERE colvalue IN $1
>> 
>> With $1 as a set or array of some sort. Unfortunately, the above doesn't
>> pass parsing.  Is there any way to do an IN query via PQexecParams that
>> doesn't involve enumerating the set of values as individual parameters?

> No but there is a way to do something equivalent with arrays:

> SELECT * FROM sometable WHERE colvalue = any($1::integer[]);

> I'm not sure which (if any) drivers have good support for arrays though.

Be aware also that if you're hoping that this will use an index on
colvalue, you need 8.2 or later to get such a plan from an "= any"
construct.

			regards, tom lane