Re: select on many-to-many relationship - Mailing list pgsql-sql

From Sergey Konoplev
Subject Re: select on many-to-many relationship
Date
Msg-id CAL_0b1vE8Fvakoc8crF2ZwUK7mDVzTBfiGf4-1PekRq2Om598A@mail.gmail.com
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In response to select on many-to-many relationship  (ssylla <stefansylla@gmx.de>)
List pgsql-sql
On Tue, Nov 27, 2012 at 2:13 AM, ssylla <stefansylla@gmx.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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