Re: How to obtain algebraic sum of equal lines

Ennio-Sr wrote:
> Hi Oisin and Frank,
>
> * Frank Bax <fbax(at)sympatico(dot)ca> [250406, 16:41]:
>
>> At 04:12 PM 4/25/06, Ennio-Sr wrote:
>>
>>
>>> Hi all,
>>> Is it possible, given the following table:
>>>
>>> cod_rif | titolo | quantity | cmf | u_qq | mont | vend | sum
>>> ---------+--------+----------+---------+--------+---------+------+-------
>>> 26 | aaa | -1000 | 6.11098 | 6.176 | 6.1110 | t | -1000
>>> 7 | aaa | 2500 | 25.455 | 0 | 60.0897 | f | 2500
>>> 28 | bbb | 2700 | 3.862 | 4.6 | 4.1957 | f | 2700
>>> 3 | bbb | 500 | 6.057 | 10.129 | 18.7311 | f | 500
>>> 34 | bbb | -700 | 0 | 0 | 0.0000 | t | -700
>>> 6 | bbb | -500 | 2.703 | 4.757 | 3.7151 | f | -500
>>> 30 | ccc | 5000 | 1.717 | 1.489 | 1.7170 | f | 5000
>>> 33 | ccc | 10000 | 4.36 | 0 | 4.3600 | f | 10000
>>> 11 | ddd | -1500 | 10.537 | 4.021 | 20.5815 | t | -1500
>>> 32 | ddd | 1500 | 0.55896 | 1.119 | 0.5590 | f | 1500
>>> (10 rows)
>>>
>>> to get a selection whereby the algebraic sum of "quantity" for each equal
>>> 'titolo'
>>> is returned?
>>>
>>> I tried this query with no result:
>>> psql finanza -c "select * , (sum(quantity)) from test_t group by cod_rif,
>>> titolo, quantity, cmf, u_qq, mont, vend order by titolo asc"
>>>
>> psql finanza -c "select titilo, (sum(quantity)) from test_t group by
>> titolo order by titolo asc"
>>
>>
>
> The point is that command would return two cols only, whereas I would
> like to have all the cols, like:
>
> 26 | aaa | 1500 | 6.11098 | 6.176 | 6.1110 | t | 1500
> 28 | bbb | 2000 | 3.862 | 4.6 | 4.1957 | f | 3200
>
> i.e. aaa=(-1000+2500=1500), bbb=(2700+500-700-500)=2000
> which, I fear, is not possible ;-(
>
>
select *,(select sum(quantity) from test_t t2 where t2.titolo=t1.titolo)
as sum from test_t t1;

would do it though who knows how inefficient this is?

Oisin