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Date: Fri, 12 Feb 2010 12:14:53 +0100
From: Louis-David Mitterrand <vindex+lists-pgsql-sql@apartia.org>
To: pgsql-sql@postgresql.org
Subject: "left join" not working?
Message-ID: <20100212111453.GA16318@apartia.fr>
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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,