RE: Order by email address by domain ?

???
I don't think anyone suggested adding a new builtin function.
Yes, your suggestion is good for an occasional use.
Where this kind of functionality is likely to be needed on a continuing
basis, my experience is that wrapping the code up in a custom function is
easier and cleaner than writing it out every time.  Saves a lot of typing,
not to mention the risk of typos (which could give spurious results without
being obvious about it).  Also, a function allows for indexing on that
value, which can be a great aid to performance.
I have found that sometimes it is better to just add a column or two to the
table to contain the needed key, because with large amounts of data that can
be much quicker.  Doing this too much though can lead to a cluttered
database, and a loss of clarity about just what all of those extra fields
are for...  It's a judgement call.
Just my $0.01 (That's $0.02 Australian :-))

> -----Original Message-----
> From:    Frank Bax [SMTP:fbax@sympatico.ca]
> Sent:    Thursday, May 10, 2001 8:53 PM
> To:    pgsql-sql@postgresql.org
> Cc:    herve@elma.fr
> Subject:    Re: Order by email address by domain ?
> 
> Why is everyone else suggesting new functions?  This works (in 6.5.3):
> 
>    ORDER BY lower(substring(email from position('@' in email)+1 )),
> lower(email)
> 
> remove the lower() functions if you don't need them (I had mixed case
> addresses).
> 
> I am guessing/assuming that it's cheaper to just use entire email address
> in second key rather than extract before the '@' character.
> 
> Frank
> 
> At 08:37 PM 5/10/01 +0200, you wrote:
> >Hi,
> >
> >I just want to order by a listing of email address by domain like :
> >
> >toto@aol.com
> >tutu@aol.com
> >toto@be.com
> >tutu@be.com
> >toto@yahoo.com
> >
> >Is it possible and how ?
> >
> >Thanks !
> >-- 
> >Hervé Piedvache
> >
> >Elma Ingenierie Informatique
> >6, rue du Faubourg Saint-Honoré
> >F-75008 - Paris - France 
> >http://www.elma.fr
> >Tel: +33-1-44949901
> >Fax: +33-1-44949902 
> >Email: herve@elma.fr
> >
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