Mailing-List: contact derby-user-help@db.apache.org; run by ezmlm
Precedence: bulk
Reply-To: "Derby Discussion" <derby-user@db.apache.org>
Received-SPF: pass (athena.apache.org: local policy)
Date: Fri, 05 Dec 2008 16:34:18 +0100
From: Knut Anders Hatlen <Knut.Hatlen@Sun.COM>
Subject: Re: ORDER BY and greek characters
In-reply-to: <4934051D.6010009@sun.com>
Sender: Knut.Hatlen@Sun.COM
To: Derby Discussion <derby-user@db.apache.org>
Message-id: <x6r64m1vr9.fsf@Sun.COM>
MIME-version: 1.0
Content-type: text/plain; charset=us-ascii
Content-transfer-encoding: 7BIT
References: <20748193.post@talk.nabble.com> <4934051D.6010009@sun.com>
User-Agent: Gnus/5.110011 (No Gnus v0.11) Emacs/22.2 (usg-unix-v)

Rick Hillegas <Richard.Hillegas@Sun.COM> writes:

> tom_ wrote:
>> I'm using ORDER BY and a database with collation territory based de_DE.
>> Strings starting with greek characters are at the end of the resultset.
>> Users would expect them near the respective latin character, e.g. greek
>> "alpha" near "a". Is there a possiblity to sort in this way?
>>     
> Hi Tom,
>
> Here a couple suggestions:
[...]
> 2) You could change Derby so that it supports user-defined Locales
> with custom collations. I haven't looked into the details here, but
> this seems like a smallish task--gated by a community discussion about
> how to declare these user-created Locales.
>
> + This would be generally useful.
> + Indexes would work for you and give your queries better performance.
> - This solution wouldn't hit production until Derby 10.5 at the earliest.

This can in fact be done with no changes to the Derby code, since Java
SE 6 has an API for defining custom locales and collation rules. I have
given an example of how you can use this to achieve what you want here:
http://blogs.sun.com/kah/entry/user_defined_collation_in_apache

Hope this helps,

-- 
Knut Anders