Subject: Re: column totals
From: Ragnar <gnari@hive.is>
To: pgsql-performance@postgresql.org
In-Reply-To: <4476D0D7.1080006@silversphere.co.za>
References: <4476D0D7.1080006@silversphere.co.za>
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Date: Fri, 26 May 2006 16:23:37 +0000
Message-Id: <1148660617.8566.51.camel@localhost.localdomain>
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On fös, 2006-05-26 at 11:56 +0200, James Neethling wrote:

> SELECT branch_id, prod_cat_id, sum(prod_profit) as prod_cat_profit
>     FROM () as b1
> WHERE x = y
> GROUP BY branch, prod_cat_id
> 
> 
> Now, I also need the branch total, effectively,
> SELECT branch_id, sum(prod_profit) as branch_total
>     FROM () as b1
> WHERE x = y
> GROUP BY branch_id.
> 
> 
> Since the actual queries for generating prod_profit are non-trivial, how 
> do I combine them to get the following select list?

one simple way using temp table and 2 steps:

CREATE TEMP TABLE foo AS
  SELECT branch_id, 
         prod_cat_id, 
         sum(prod_profit) as prod_cat_profit
  FROM () as b1
  WHERE x = y
  GROUP BY branch, prod_cat_id;

SELECT branch_id, 
       prod_cat_id, 
       prod_cat_profit,
       branch_total
FROM foo as foo1 
     JOIN 
       (SELECT branch_id, 
               sum(prod_cat_profit) as branch_total
        FROM foo
        GROUP BY branch_id 
       ) as foo2 USING branch_id;


(untested)

gnari