From: msi77 <msi77@yandex.ru>
To: Louis-David Mitterrand <vindex+lists-pgsql-sql@apartia.org>
Cc: pgsql-sql@postgresql.org
Subject: Re: "left join" not working?
Date: Fri, 12 Feb 2010 14:57:10 +0300
Message-ID: <23141265975830@webmail112.yandex.ru> (raw)
In-Reply-To: <20100212111453.GA16318@apartia.fr>
References: <20100212111453.GA16318@apartia.fr>
> where p.id_line=1
this filters rows after join was applied. Try this
select c.id_currency,max(p.modified_on) from currency c left join
price_line p using (id_currency) where (p.id_line=1 or p.id_line is null) group by
c.id_currency;
> Hi,
> This query:
> select c.id_currency,max(p.modified_on) from currency c left join
> price_line p using (id_currency) where p.id_line=1 group by
> c.id_currency;
> doesn't list all c.id_currency's, only those with a price_line. However
> this one does:
> select c.id_currency,max(p.modified_on) from currency c left join
> price_line p on (p.id_currency = c.id_currency and p.id_line=1) group by
> c.id_currency;
> How come?
> Thanks,
> --
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To: pgsql-sql@postgresql.org
Cc: msi77@yandex.ru, vindex+lists-pgsql-sql@apartia.org
Subject: Re: "left join" not working?
In-Reply-To: <23141265975830@webmail112.yandex.ru>
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