Date: Mon, 30 Jan 2006 20:38:22 +0000
To: pgsql-interfaces@postgresql.org
Subject: Find out if a parameter/return field is NULLABLE using Describe
Message-ID: <20060130203822.GA16111@furbychan.cocan.org>
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From: Richard Jones <rich@annexia.org>


It doesn't seem to be possible to find out if a parameter or result
field is nullable using the Describe protocol.

For example if I have this table and statement:

  create table employees (
    id serial not null primary key,
    name text not null,
    email text                            <-- this field
  );

  insert into employees (name, email) values ($1, $2);

Then the only information I get back about $2 is that it's a TEXT (OID
= 25), when clearly $1 and $2 are different in that one is nullable
and the other isn't.

Similarly,

  select name, email from employees;

This time I get more information about the types, including a modifier
and length, but I can't see whether that lets me find out that one
could be NULL and the other can never be.

So is this possible?

Rich.

-- 
Richard Jones, CTO Merjis Ltd.
Merjis - web marketing and technology - http://merjis.com
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