It should be done using subqueries.
select ..., ( select sum(val)-sum(paid) from invoices i2 where i2.invoice_id<i.invoice_id and i2.cust_id=i.cust_id
)
from invoices i
On 22 Jun 2001, Domingo Alvarez Duarte wrote:
> I have a problem that requires what I call a incremental sum, lets say
> I have the folowing table (for simplicity):
>
> table invoices_not_paid(cust_id int, invoice_id int, val numeric, paid
> numeric);
>
> with the folowing values:
>
> cust_id invoice_id val paid
> ----------------------------------
> 1 23 10.50 3.40
> 1 34 5.70 0.0
> 1 67 23.89 4.50
>
>
> I want show a list like this:
>
> cust_id invoice_id val paid incremental_not_paid_sum
> -----------------------------------------------------------------
> 1 23 10.50 3.40 (10.50 - 3.40) 7.10
> 1 34 5.70 0.0 (7.10 + 5.70 - 0.0) 12.80
> 1 67 23.89 4.50 (12.80 + 23.89 - 4.50) 31.19
>
> The operations betwen () are showed only to explain how the
> incremental_not_paid_sum is calculated, The operation requires a
> reference to a previous column or a partial sum of columns till that
> moment, someone has an idea how this can be done using sql ?
>
> ---------------------------(end of broadcast)---------------------------
> TIP 4: Don't 'kill -9' the postmaster
>
>
