From: Rob Sargent <robjsargent@gmail.com>
To: pgsql-sql@postgresql.org
Subject: Re: left outer join on more than 2 tables?
Date: Tue, 16 Jun 2009 15:40:27 -0600
Message-ID: <4A38114B.7090106@gmail.com> (raw)
In-Reply-To: <396486430906161425i1cb7949enff5443cc2043805a@mail.gmail.com>
References: <4A3807CF.90109@consumercontact.com>
<396486430906161425i1cb7949enff5443cc2043805a@mail.gmail.com>
Richard Broersma wrote:
> On Tue, Jun 16, 2009 at 1:59 PM, Carol
> Cheung<cacheung@consumercontact.com> wrote:
>
>> I would like to find the counts of complaints by region and I would like all
>> regions to be displayed, regardless of whether or not complaints exist for
>> that region. Is left outer join what I'm looking for?
>>
>
> SELECT R.region_name, Count(*) AS RegionComplaints
> FROM Region AS R
> LEFT JOIN City AS Ci
> ON R.id = C.region_id
> LEFT JOIN Complaint AS Cm
> ON Ci.id = Cm.city_id
> GROUP BY R.region_name;
>
>
>
Is there a city without a reference to region? And wouldn't you want to
count(cm.id)?
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To: pgsql-sql@postgresql.org
Cc: robjsargent@gmail.com
Subject: Re: left outer join on more than 2 tables?
In-Reply-To: <4A38114B.7090106@gmail.com>
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