Re: SELECT with sum on groups ORDERING by the subtotals

Hi !

This is not possible because the query will have a time interval and the
subtotal will change due the intervals passed to the query...
To get the subtotal I already know how to do it (see below) but the
problem is get the correct output, ordering by the bigger totals
agrouped by product code

CREATE TYPE subtotal_type AS
(code varchar(15),
description varchar(60),
quant float8,
price float8,
total float8,
subtotal float8);

CREATE OR REPLACE FUNCTION product_sales()
RETURNS SETOF subtotal_type AS
$BODY$
DECLARE
tbrow RECORD;
sbrow subtotal_type;

BEGIN
sbrow.subtotal := 0;
FOR tbrow IN
SELECT code, description, quant, price, total FROM test ORDER BY code
LOOP

IF sbrow.code = tbrow.code THEN
sbrow.subtotal := sbrow.subtotal + tbrow.total;
ELSE
sbrow.subtotal := tbrow.total;
END IF;
sbrow.code := tbrow.code;
sbrow.description := tbrow.description;
sbrow.quant := tbrow.quant;
sbrow.price := tbrow.price;
sbrow.total := tbrow.total;

RETURN NEXT sbrow;
END LOOP;

RETURN;

END;
$BODY$
LANGUAGE 'plpgsql' VOLATILE;

With this function my output is:

dadosadv=# SELECT * FROM product_sales();
code | description | quant | price | total | subtotal
-------+-------------+-------+-------+-------+----------
92110 | PRODUCT A | 10 | 1 | 10 | 10
92110 | PRODUCT A | 5 | 0.9 | 9 | 19
92110 | PRODUCT A | 100 | 0.9 | 90 | 109
92110 | PRODUCT A | 10 | 1.1 | 11 | 120
92190 | PRODUCT b | 10 | 1.1 | 11 | 11
92190 | PRODUCT b | 10 | 1.1 | 11 | 22
92190 | PRODUCT b | 10 | 1.1 | 11 | 33
92190 | PRODUCT b | 20 | 0.8 | 8 | 41
99120 | PRODUCT C | 10 | 0.8 | 8 | 8
99120 | PRODUCT C | 100 | 0.8 | 80 | 88
99120 | PRODUCT C | 200 | 0.8 | 160 | 248
99120 | PRODUCT C | 100 | 0.9 | 90 | 338
(12 rows)

The only problem that I have is that I need to order by the
max(subtotal) aggrouped by code. My desired output is:

code | description | quant | price | total | subtotal
-------+-------------+-------+-------+-------+----------
99120 | PRODUCT C | 10 | 0.8 | 8 | 8
99120 | PRODUCT C | 100 | 0.8 | 80 | 88
99120 | PRODUCT C | 200 | 0.8 | 160 | 248
99120 | PRODUCT C | 100 | 0.9 | 90 | 338
92110 | PRODUCT A | 10 | 1 | 10 | 10
92110 | PRODUCT A | 5 | 0.9 | 9 | 19
92110 | PRODUCT A | 100 | 0.9 | 90 | 109
92110 | PRODUCT A | 10 | 1.1 | 11 | 120
92190 | PRODUCT b | 10 | 1.1 | 11 | 11
92190 | PRODUCT b | 10 | 1.1 | 11 | 22
92190 | PRODUCT b | 10 | 1.1 | 11 | 33
92190 | PRODUCT b | 20 | 0.8 | 8 | 41

Any tip?

Regards,

Rodrigo Carvalhaes

Gnanavel Shanmugam wrote:

>I think it will be better to add one more column for subtotal and
>write an "on before insert" trigger to update the subtotal with sum of
>total.
>
>
>
>
>>-----Original Message-----
>>From: grupos(at)carvalhaes(dot)net
>>Sent: Thu, 16 Jun 2005 00:56:42 -0300
>>To: pgsql-sql(at)postgresql(dot)org
>>Subject: [SQL] SELECT with sum on groups ORDERING by the subtotals
>>
>>Hi Guys!
>>
>>I need to make a complex query. I am thinking to use plpgsql BUT I am
>>confused how I can solve this.
>>
>>What I have:
>>CREATE TABLE test
>>(
>> code varchar(15),
>> description varchar(60),
>> group varchar(10),
>> quant float8,
>> price float8,
>> total float8
>>)
>>WITHOUT OIDS;
>>
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('92110', 'PRODUCT A', 10, 1, 10);
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('92110', 'PRODUCT A', 5, 0.90, 9);
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('92110', 'PRODUCT A', 100, 0.9, 90);
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('92110', 'PRODUCT A', 10, 1.1, 11);
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('92190', 'PRODUCT b', 10, 1.1, 11);
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('92190', 'PRODUCT b', 10, 1.1, 11);
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('92190', 'PRODUCT b', 10, 1.1, 11);
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('92190', 'PRODUCT b', 20, 0.8, 8);
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('99120', 'PRODUCT C', 10, 0.8, 8);
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('99120', 'PRODUCT C', 100, 0.8, 80);
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('99120', 'PRODUCT C', 200, 0.8, 160);
>>INSERT INTO test (code, description, quant, price, total) VALUES
>>('99120', 'PRODUCT C', 100, 0.9, 90);
>>
>>
>>I need an subtotal for all the products with the same group and that the
>>query be ordered by the bigger subtotal.
>>
>>For example, I need an output like this:
>>Ex.
>>
>>
>> code | description | quant | price | total | subtotal
>>-------+-------------+-------+-------+-------+----------
>> 99120 | PRODUCT C | 10 | 0.8 | 8 | 8
>> 99120 | PRODUCT C | 100 | 0.8 | 80 | 88
>> 99120 | PRODUCT C | 200 | 0.8 | 160| 168
>> 99120 | PRODUCT C | 100 | 0.9 | 90 | 667
>> 92110 | PRODUCT A | 10 | 1 | 10 | 10
>> 92110 | PRODUCT A | 5 | 0.9 | 9 | 19
>> 92110 | PRODUCT A | 100 | 0.9 | 90 | 109
>> 92110 | PRODUCT A | 10 | 1.1 | 11 | 120
>> 92190 | PRODUCT b | 10 | 1.1 | 11 | 11
>> 92190 | PRODUCT b | 10 | 1.1 | 11 | 22
>> 92190 | PRODUCT b | 10 | 1.1 | 11 | 33
>> 92190 | PRODUCT b | 20 | 0.8 | 8 | 41
>>
>>The subtotal column must sum all the products with the same code and put
>>the result in order of the bigger sultotals.
>>
>>Only make a function that sum the last value + the subtotal it's not
>>hard BUT how I can make the subtotal restart when the code changes and
>>how I will order the result by the bigger subtotal code groups?
>>
>>Thanks!
>>
>>Rodrigo Carvalhaes
>>
>>--
>>Esta mensagem foi verificada pelo sistema de antivírus e
>> acredita-se estar livre de perigo.
>>
>>
>>---------------------------(end of broadcast)---------------------------
>>TIP 7: don't forget to increase your free space map settings
>>
>>
>
>
>with regards,
>S.Gnanavel
>
>

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Esta mensagem foi verificada pelo sistema de antivrus e
acredita-se estar livre de perigo.