Re: How to obtain algebraic sum of equal lines

[Oisin Glynn <me(at)oisinglynn(dot)com>]

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