Re: array_accum() and quoted content

From: David Fetter <david(at)fetter(dot)org>
To: "Raymond C(dot) Rodgers" <sinful622(at)gmail(dot)com>
Cc: Alvaro Herrera <alvherre(at)commandprompt(dot)com>, pgsql-general(at)postgresql(dot)org
Subject: Re: array_accum() and quoted content
Date: 2008-07-29 00:52:19
Message-ID: 20080729005219.GA6980@fetter.org
Views: Raw Message | Whole Thread | Download mbox | Resend email
Thread:
Lists: pgsql-general

On Mon, Jul 28, 2008 at 04:11:26PM -0400, Raymond C. Rodgers wrote:
> Alvaro Herrera wrote:
>> Raymond C. Rodgers escribió:
>>
>>
>>> Drat, thanks. Other than array_accum() I've never used arrays in
>>> PostgreSQL, so I wasn't aware of that behavior.
>>>
>>
>> Why do you want to use array_accum() in the first place? Maybe there
>> are better ways to do what you are using it for, that do not subject you
>> to the awkward ways of arrays.
>>
> I'm not a database professional, so I'll explain this as best I can.
> There are two tables that are linked via entries in a third: company,
> publisher, and company-publisher association. A publisher can be
> referenced by multiple companies, so the company-publisher association
> table is a simple two column table that consists of foreign keyed
> references to the company table's primary key and the publisher table's
> primary key. The query in which I'm using array_accum() is building a
> list of companies and the associated publishers for each. For example:
>
> SELECT c.company_id, c.company_name, array_accum(p.publisher_name) AS
> publishers FROM company_table c LEFT JOIN company_publisher_assoc cpa ON
> c.company_id = cpa.company_id LEFT JOIN publisher_table p ON
> cpa.publisher_id = p.publisher_id GROUP BY c.company_id, c.company_name
> ORDER BY company_name

You could do something like

array_to_string(
array_accum(p.publisher_name),
'|' -- or any other string guaranteed not to appear in the publisher_name
)

Cheers,
David.
--
David Fetter <david(at)fetter(dot)org> http://fetter.org/
Phone: +1 415 235 3778 AIM: dfetter666 Yahoo!: dfetter
Skype: davidfetter XMPP: david(dot)fetter(at)gmail(dot)com

Remember to vote!
Consider donating to Postgres: http://www.postgresql.org/about/donate

In response to

Browse pgsql-general by date

  From Date Subject
Next Message Yi Zhao 2008-07-29 01:14:39 Re: why my postgresql auto crashed???
Previous Message Raymond C. Rodgers 2008-07-28 23:01:28 Re: array_accum() and quoted content