Need modify Running total query

Question

CREATE TABLE DET
(DDT DATE,
DNO NUMBER,
DCODE VARCHAR2(6),
DAMOUNT NUMBER,
DINST NUMBER);
INSERT INTO DET VALUES (TO_DATE('01012010','DD/MM/YYYY'),7,1946,19674.5,NULL);
INSERT INTO DET VALUES (TO_DATE('08012010','DD/MM/YYYY'),8,1574,4800,NULL);
INSERT INTO DET VALUES (TO_DATE('08012010','DD/MM/YYYY'),8,1574,50000,208.333);
INSERT INTO DET VALUES (TO_DATE('08012010','DD/MM/YYYY'),9,1835,31600,208.333);
INSERT INTO DET VALUES (TO_DATE('08012010','DD/MM/YYYY'),6,1924,50000,232.558);
INSERT INTO DET VALUES (TO_DATE('02022010','DD/MM/YYYY'),9,1835,5000,NULL);
INSERT INTO DET VALUES (TO_DATE('02022010','DD/MM/YYYY'),9,1835,31600,131.667);
INSERT INTO DET VALUES (TO_DATE('05022010','DD/MM/YYYY'),8,1574,50000,208.333);
INSERT INTO DET VALUES (TO_DATE('10022010','DD/MM/YYYY'),6,1924,50000,232.558);
INSERT INTO DET VALUES (TO_DATE('01032010','DD/MM/YYYY'),8,1574,50000,208.333);
INSERT INTO DET VALUES (TO_DATE('01032010','DD/MM/YYYY'),6,1924,50000,232.558);
i have this query ;
SCOTT@orcl>select ddt,
  2  dno,
  3  dcode,
  4  newdamount damount,
  5  dinst,
  6  newdamount-nvl(dinst,0) run_tot
  7  from(
  8  select ddt,
  9  dno,
10  dcode,
11  damount,
12  dinst,
13  decode(nvl(to_number(to_char(ddt,'MM'))-1,0),0,damount,
14  damount-nvl(dinst,0)*(to_number(to_char(ddt,'MM'))-1)) newdamount
15  from det
16  order by ddt)
17  where dcode = '1835'
18  order by ddt,dno,damount,dinst nulls first;
it returns this result;
DDT               DNO DCODE     DAMOUNT      DINST    RUN_TOT
08/01/2010          9 1835        31600    208.333  31391.667
02/02/2010          9 1835         5000                  5000
02/02/2010          9 1835    31468.333    131.667  31336.666
The results last row should appear like this;
02/02/2010          9 1835    31391.667    131.667  31260 DAMOUNT for the row 02/02/2010 (where DINST > 0 ) should be 31391.667,(closing RUN_TOT of january)
and NOT 31468.333.
The above query logic could be enitrely wrong, because the criteria laid assuming that the instalment remains same every month.
Please someone who is well-verse with Lag or Sum ..Over analytic function, correct my code.
TY.

Answer 1

user613563 wrote:
Your query entirely missed one row with DAMOUNT 5000.
i expect the result to be;
DDT               DNO DCODE     DAMOUNT      DINST    RUN_TOT
08/01/2010          9 1835        31600    208.333  31391.667
02/02/2010          9 1835         5000                  5000
02/02/2010          9 1835    31391.667    131.667  31260
Well, i for one am not following the logic here, but this will give you the results you've posted (why doesn't the row with damount = 5000 factor in to the 'running total' in any way shape or form?)
select
  ddt, dno, dcode, damount, dinst, resolved
from
  select
    ddt, dno, dcode, damount, dinst,
    case when lag(trunc(ddt, 'MM')) over (order by ddt asc) != trunc(ddt, 'MM')
    then
      lag(damount-dinst) over (order by ddt asc) - dinst
    else
      damount-dinst
    end as resolved
  from det
  where dcode = '1835'
  and dinst is not null
    union all
  select
    ddt, dno, dcode, damount, dinst,
    damount as resolved
  from det
  where dcode = '1835'
  and dinst is null
  order by ddt asc, dinst nulls first
)Edited by: Tubby on Jan 11, 2010 2:47 PM
fixed the not equals sign since the forum eats less than / greater than symbols