Is it possible in oracle?(need very badly)

Question

Hi,
I need to write a select statement for a report and i need to check with previous record.
here I'm giving the data and table structure also.
conditions are :
seltest is variable in there we have to show Y Or N
extension is null and service center has data the 'Y'
extension is not null and previous extension is null and previous service center is not null 'Y'
extension is not null and previous extension is not null and SELTST is 'Y' then 'Y'
Here the sample data.
CREATE GLOBAL TEMPORARY TABLE GT_T
REPORT_NO NUMBER,
EXTENSION VARCHAR2(10 BYTE),
SVCE_CENTER VARCHAR2(10 BYTE),
RNO NUMBER
ON COMMIT PRESERVE ROWS
Insert into gt_test
(REPORT_NO, SVCE_CENTER, RNO, CURR, PREV)
Values
(36071, 'MACMB', 6, 1, 0);
Insert into gt_test
(REPORT_NO, EXTENSION, SVCE_CENTER, RNO, CURR, PREV)
Values
(36071, 'E', 'MACMB', 1, 2, 1);
Insert into gt_test
(REPORT_NO, EXTENSION, SVCE_CENTER, RNO, CURR, PREV)
Values
(36071, 'E', 'MACMB', 1, 3, 2);
Insert into gt_test
(REPORT_NO, SVCE_CENTER, RNO, CURR, PREV)
Values
(36074, 'ASPEN', 4, 1, 0);
Insert into gt_test
(REPORT_NO, EXTENSION, SVCE_CENTER, RNO, CURR, PREV)
Values
(36074, 'E', 'ASPEN', 2, 2, 1);
Insert into gt_test
(REPORT_NO, EXTENSION, SVCE_CENTER, RNO, CURR, PREV)
Values
(36074, 'E', 'ASPEN', 2, 3, 2);
Insert into gt_test
(REPORT_NO, EXTENSION, SVCE_CENTER, RNO, CURR, PREV)
Values
(36074, 'E', 'ASPEN', 2, 4, 3);
COMMIT;
Pls help me out your help is greatly appreciated.
Thanks & Regards,
Ramana.

Answer 1

Kamal,
My table is having 4 columns .
Data is like this.
Report_No     Extension svce_center rno
36071     null MACMB 6
36071      E null 1
36071 E null 1
36074     null null 2
36074     E      ASPEN 4
36074     E     DECKR 4
36074 E     DELWR 4
36074     E TLBOT 4
Output Looks like this :
Report_No     Extension svce_center rno stest
36071     null MACMB 6 Y
36071      E null 1 N
36071     E null 1 N
36074     null null 2 N
36074 E      ASPEN 4 Y
36074     E     DECKR 4 Y
36074     E     DELWR 4 Y
36074     E TLBOT 4 Y
conditon 1: extension is null and service center has data the 'Y'
conditon 2: extension is not null and previous extension is null and previous service center is not null then stest 'Y'
conditon 3: extension is not null and previous extension is not null and previous stest is 'Y' then stest 'Y'
else 'N'
on basis of above conditions I have to show my output like above. I'm able to achive some level means for report no 36074 I got the result upto DECKR for next record i need write one more subquery. Here I have only 5 rows only . If I have more than that means 10 rows for report no then i have to write sub select 10 times right. Is there any other way to do this.
This is query currently i'm using.
select report_no,extension,svce_center,prv_ext,prv_svce_cent,STEST,
(case when extension is null and svce_center is not null then 'Y'
when extension is not null and prv_ext is null and prv_svce_cent is not null then 'Y'
when extension is not null and prv_ext is not null and
st1 is not null then 'Y'
END )sltest
from (
     select report_no,extension,svce_center,prv_ext,prv_svce_cent,stest,
     lag(stest,1) over (order by report_no) st1,
     lead(stest,1) over (order by report_no) st2
     from (
          select report_no,extension,svce_center,prv_ext,prv_svce_cent,
               (case when extension is null and svce_center is not null then 'Y'
               when extension is not null and prv_ext is null and
               prv_svce_cent is not null then 'Y'
               end )stest
          from (
                         select report_no,extension,
               (case when lag(extension,1) over (order by report_no)=extension then 1 else null end) prv_ext,
                    svce_center,
                    (case when lag(svce_center,1) over (order by report_no)=svce_center then 1 else null end)prv_svce_cent,
                    rno
               from gt_test
               order by report_no
Thanks & Regards,
Ramana.