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Date: Mon, 19 Dec 2005 09:54:49 -0700
From: Michael Fuhr <mike@fuhr.org>
To: george young <gry@ll.mit.edu>
Cc: pgsql-sql@postgresql.org
Subject: Re: how to convert relational column to array?
Message-ID: <20051219165449.GA99764@winnie.fuhr.org>
References: <20051219110612.26de2268.gry@ll.mit.edu>
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On Mon, Dec 19, 2005 at 11:06:12AM -0500, george young wrote:
> create table new_tab(name text, id int, permits text[]);
> 
> -- I insert one row per name:
> insert into new_tab select distinct name,id,cast('{}' as text[]) from old_tab;
> 
> Now I want to fold all the 'permits' values into the new permits arrays.

In PostgreSQL 7.4 and later you can build an array from a select,
so I think the following update should work (it did for me when I
tested it):

UPDATE new_tab SET permits = array(
  SELECT permits
  FROM old_tab
  WHERE old_tab.name = new_tab.name AND old_tab.id = new_tab.id
);

-- 
Michael Fuhr