> -----Original Message-----
> From: Andreas Pflug [mailto:pgadmin@pse-consulting.de] 
> Sent: Wednesday, January 07, 2004 11:17 AM
> To: Dann Corbit
> Cc: pgsql-hackers@postgresql.org
> Subject: Re: [HACKERS] Dumb question: How do I determine 
> programmatically if a column is nullable?
> 
> 
> Dann Corbit wrote:
> 
> > What API call can I make to find out if a column is nullable or not?
> >  
> 
> SELECT attnotnull FROM pg_attribute ...
> see documentation "Internals/System Catalogs"

Is there a way do do it when I have some arbitrary query that returns a
result set?

In other words, I will be passed a SQL query.  I don't want to have to
parse it myself.

Rather, I want to know (for the bound columns) if a column is nullable
or not.

Is the functionality available in [for example] libpq?

Wed, 7 Jan 2004 18:18:39 -0800
"Dann Corbit" <DCorbit@connx.com>
Re: Dumb question: How do I determine programmatically if a column is
	nullable?
"Dann Corbit" <DCorbit@connx.com> writes:
> In other words, I will be passed a SQL query.  I don't want to have to
> parse it myself.
> Rather, I want to know (for the bound columns) if a column is nullable
> or not.
> Is the functionality available in [for example] libpq?

As of 7.4, see PQftable() and PQftablecol(), and look into pg_attribute
to see whether the column is marked NOTNULL.

			regards, tom lane

Thu, 08 Jan 2004 00:41:50 -0500
Tom Lane <tgl@sss.pgh.pa.us>
Re: Dumb question: How do I determine programmatically if a column is
	nullable?