Re: summing tables

Erik Thiele wrote:

>hi,
>
>i have a table consisting of 4 integers.
>
>seq is for making the table ordered. (ORDER BY SEQ ASC)
>a,b,c maybe null
>
>
> seq | a  | b  | c 
>-----+----+----+---
>   0 |  1 |  2 | 3
>   1 |  1 |  2 |  
>   2 |  5 |  7 |  
>   3 | -2 | -4 |  
>
>
>i am needing a sql statement to do
>
>c=a+b+"the c of the row with seq one less than myself"
>
>this statement has to run over the whole table, in seq order.
>
>
>how can this be acomplished???
>
>
>cu&thanks
>erik
>
>
>  
>
Hi Erik,
this should do the trick:
(I have not yet considered the NULLS though...)
UPDATE table t set c = a + b + (Select c from table tt where tt.seq = 
t.seq -1)

Cheers, Dani