Message-Id: <199912040931.UAA01301@mustang.sdc.com.au>
To: Peter Eisentraut <peter_e@gmx.net>
cc: pgsql-sql@postgreSQL.org,
	Marcin Mazurek - Multinet SA - Poznan <m.mazurek@multinet.pl>
Subject: Re: [SQL] arrays 
In-Reply-To: Message from Peter Eisentraut <peter_e@gmx.net> of "Sat,
	04 Dec 1999 03:23:30 BST."
	<Pine.LNX.4.20.9912021935560.384-100000@localhost.localdomain>
Mime-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Date: Sat, 04 Dec 1999 20:01:58 +1030
From: Stephen Davies <scldad@sdc.com.au>
Content-Transfer-Encoding: 8bit

Arrays do have a role in life: even in a "proper relational" world.

The classical examples are publications with multiple authors, ISBns, 
subjects, keywords etc.

Trying to fully normalise attributes like these leads to nonsensical and 
unusable database designs.

Cheers,
Stephen.

Peter Eisentraut <peter_e@gmx.net>  wrote:
> Don't use arrays. They look very promising but they aren't. Most of these
> kind of questions can be resolved by designing a proper relational
> database schema.
> 
> On 1999-12-01, Marcin Mazurek - Multinet SA - Poznan mentioned:
> 
> > Hi,
> > I have a table: orders (id int, val INT4[][]);. The question is how to
> > select in separate rows values from particular id?
> > 
> > example:
> > insert into orders values(1,'{{1,1},{1,4},{2,3}}');
> > select val from orders where id=1; gives me:
> > val
> > -------------------
> > {{1,2},{1,4},{2,3}}
> > 
> > How can I make from it to columned table with first and second int
> > separated?
> > 
> > mazek
> > 
> > 
> > 
> > ************
> > 
> > 
> 
> -- 
> Peter Eisentraut                  Sernanders väg 10:115
> peter_e@gmx.net                   75262 Uppsala
> http://yi.org/peter-e/            Sweden
> 
> 
> 
> ************


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