From: Richard Huxton <dev@archonet.com>
To: Filipe Bonjour <fbonjour@urbanet.ch>
To: pgsql-sql@postgresql.org
Subject: Re: Can arrays reference primary keys in CREATE TABLE?
Date: Wed, 14 May 2003 16:31:48 +0100
Message-ID: <200305141631.48642.dev@archonet.com> (raw)
In-Reply-To: <pan.2003.05.09.21.21.24.908732@urbanet.ch>
References: <pan.2003.05.09.21.21.24.908732@urbanet.ch>
On Friday 09 May 2003 10:21 pm, Filipe Bonjour wrote:
> Hi,
>
> I'm a rather new SQL user, and I found interesting that you can
> use "references" to make sure that a value inserted in a table is a
> primary key from another table. Something like:
Yep - referential integrity is vital.
> However, I'd like to define a table containing an array, and that
> all elements of the array be a primary key from another table, so I
> tried:
>
> create table tb (
> a_ref integer[] references ta(a_id)
> );
>
> But that doesn't work, I think because an array of integers can't
> be directly compared to an integer.
Don't use arrays, use another table, e.g.
CREATE TABLE tb_items (
tb_ref integer REFERENCE tb,
ta_ref integer REFERENCES ta,
PRIMARY KEY (tb_ref,ta_ref)
);
--
Richard Huxton
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To: pgsql-sql@postgresql.org
Cc: dev@archonet.com, fbonjour@urbanet.ch
Subject: Re: Can arrays reference primary keys in CREATE TABLE?
In-Reply-To: <200305141631.48642.dev@archonet.com>
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