Date: Tue, 31 May 2005 12:17:08 -0500
From: Bruno Wolff III <bruno@wolff.to>
To: lucas@presserv.org
Cc: pgsql-sql@postgresql.org
Subject: Re: Sum() rows
Message-ID: <20050531171708.GB5899@wolff.to>
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	lucas@presserv.org, pgsql-sql@postgresql.org
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On Tue, May 31, 2005 at 13:36:48 -0300,
  lucas@presserv.org wrote:
> Hi.
> How can I sum a row and show the sum for each row???

Since in your example the id field gives the ordering, you can use a subselect
to add up the subtotal for rows with and id less than or equal to the value
of id for the current row.

> For example, in a finances table that have the total movimentation(debit/credit)
> in the bank.
> 
> i.e:
> CREATE TABLE TB1 (id integer primary key, value numeric);
> insert into tb1 values (1,20);
> insert into tb1 values (2,2);
> insert into tb1 values (3,3);
> insert into tb1 values (4,17);
> insert into tb1 values (5,-0.5);
> insert into tb1 values (6,3);
> 
> I want a query that returns:
> -id- | --- value --- | --- subtot ---
>    1 |        20.00  |         20.00
>    2 |         2.00  |         22.00
>    3 |         3.00  |         25.00
>    4 |        17.00  |         42.00
>    5 |        -0.50  |         41.50
>    6 |         3.00  |         44.50
> 
> The subtot colum will be the "prev. subtot colum"+"value colum". :-/
> I dont know how to make the "subtot" colum, I tried to use the sum() function
> but it not works correctly.
> Any idea???
> 
> Thanks.
> 
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