Re: select on many-to-many relationship

From: Sergey Konoplev <gray(dot)ru(at)gmail(dot)com>
To: ssylla <stefansylla(at)gmx(dot)de>
Cc: pgsql-sql <pgsql-sql(at)postgresql(dot)org>
Subject: Re: select on many-to-many relationship
Date: 2012-11-28 00:27:21
Message-ID: CAL_0b1vE8Fvakoc8crF2ZwUK7mDVzTBfiGf4-1PekRq2Om598A@mail.gmail.com
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On Tue, Nov 27, 2012 at 2:13 AM, ssylla <stefansylla(at)gmx(dot)de> wrote:
> id_project|id_product
> 1|1
> 1|2
> 2|1
>
> How can I create an output like this:
> id_project|id_product1|id_product2
> 1|1|2
> 2|1|NULL

You can use the crostab() function from the tablefunc module
(http://www.postgresql.org/docs/9.2/static/tablefunc.html) It does
exactly what you need.

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Sergey Konoplev
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