Skip site navigation (1) Skip section navigation (2)

Re: How to determine if a function exists

From: Tom Lane <tgl(at)sss(dot)pgh(dot)pa(dot)us>
To: "lmanorders" <lmanorders(at)gmail(dot)com>
Cc: pgsql-novice(at)postgresql(dot)org
Subject: Re: How to determine if a function exists
Date: 2012-09-05 22:10:49
Message-ID: 13147.1346883049@sss.pgh.pa.us (view raw or flat)
Thread:
Lists: pgsql-novice
"lmanorders" <lmanorders(at)gmail(dot)com> writes:
> I'm attempting to determine if a stored procedure exists. If it doesn't, then I want to create it. I'm developing in C++ using the libpq interface. I found the following suggestion in the docs to determine if a function exists or not. I tried creating what I think is an identical query in pgAdmin and it seems to work ok. Can anyone tell me why the following always returns PGRES_TUPLE_OK, whether the function exists or not?

PGRES_TUPLES_OK means you successfully executed a SELECT (or other
command capable of returning tuples).  It doesn't imply anything about
how many tuples were returned.  In this case, you'd want to check for
PQntuples() > 0, as well.  And perhaps think about what you'd do if
you got more than one match, which is quite possible in view of function
overloading, schema search path, etc.

			regards, tom lane


In response to

Responses

pgsql-novice by date

Next:From: lmanordersDate: 2012-09-05 22:35:26
Subject: Re: How to determine if a function exists
Previous:From: lmanordersDate: 2012-09-05 21:59:55
Subject: How to determine if a function exists

Privacy Policy | About PostgreSQL
Copyright © 1996-2014 The PostgreSQL Global Development Group