Case Statement in sub query

Question

Hi, I have two issues, here is my initial code:
select
cc.name_id_no
,cc.discover_date
,cc.cla_case_no
,max(rl.year_of_incident)Non_Loss_Past_5
,rl.timestamp
from cla_case cc, rbn_loss rl
where cc.name_id_no = rl.customer_no
and rl.year_of_incident < trunc(cc.discover_date)
and rl.type_of_loss < 1000
and rl.timestamp < trunc(cc.discover_date)
and (cc.question_class = 20
or cc.question_class = 25)
and (trunc(cc.discover_date)- (rl.year_of_incident)) < 1095
--and (trunc(cc.discover_date) <> (rl.year_of_incident))
group by cc.cla_case_no,name_id_no, cc.discover_date,rl.timestamp
Now a cla_case_no can map to several year_of_incident. I only want the cla_case_no that maps to the max year_of_incident ie There should only be a single cla_case_no corresponding to the max year_of_incident.
To get around this I did the following which is not very efficient and I'm hoping it can be improved:
select distinct z.cla_case_no from (
select
cc.name_id_no
,cc.discover_date
,cc.cla_case_no
,max(rl.year_of_incident)Non_MW_Loss_Past_5
,rl.timestamp
from cla_case cc, rbn_loss rl
where cc.name_id_no = rl.customer_no
and rl.year_of_incident < trunc(cc.discover_date)
and rl.type_of_loss < 1000
and rl.timestamp < trunc(cc.discover_date)
and (cc.question_class = 20
or cc.question_class = 25)
and (trunc(cc.discover_date)- (rl.year_of_incident)) < 1095
--and (trunc(cc.discover_date) <> (rl.year_of_incident))
group by cc.cla_case_no,name_id_no, cc.discover_date,rl.timestamp
) z
Now comes the second issue: The above is actually a subquery that will link to a bigger table via cla_case_no ccx
SELECT
ie ,(select distinct z.cla_case_no from (
select cc.name_id_no, cc.discover_date ,cc.cla_case_no, max(rl.year_of_incident)Non_MW_Loss_Past_5, rl.timestamp
from cla_case cc, rbn_loss rl
where cc.name_id_no = rl.customer_no
and rl.year_of_incident < trunc(cc.discover_date)
and rl.type_of_loss < 1000
and rl.timestamp < trunc(cc.discover_date)
and (cc.question_class = 20
or cc.question_class = 25)
and (trunc(cc.discover_date)- (rl.year_of_incident)) < 1095
--and (trunc(cc.discover_date) <> (rl.year_of_incident))
group by cc.cla_case_no,name_id_no, cc.discover_date,rl.timestamp
) z
where z.cla_case_no = ccx.cla_case_no
) Non_MW_Loss_Past_5
FROM etc
Now only certain cc.cla_case_no from the subquery will corresp to the ccx_cla_case_no from the main table and the other entries will be null.
What I require is that if the subquery returns a result that IS NOT NULL to return 'Y' ELSE 'N' instead of the varies cla_case_no's and (null) entries in the Non_MW_Loss_Past_5 column
Thanks!!!
Banner:
Oracle Database 11g Release 11.2.0.2.0 - 64bit Production
PL/SQL Release 11.2.0.2.0 - Production
"CORE 11.2.0.2.0 Production"
TNS for Linux: Version 11.2.0.2.0 - Production
NLSRTL Version 11.2.0.2.0 - Production

Answer 1

Hi,
It looks like you have another copy of this question:
Case Statement and sub query
That's probably not your fault, but you should mark the other copy as "Answered" right away, and then you'll only have to look for replies in one place.
885178 wrote:
... Now a cla_case_no can map to several year_of_incident. I only want the cla_case_no that maps to the max year_of_incident ie There should only be a single cla_case_no corresponding to the max year_of_incident.If you know there will only be one, then you can use LAST, and you don't need GrOUP BY
To get around this I did the following which is not very efficient and I'm hoping it can be improved:
select distinct z.cla_case_no from (
select
cc.name_id_no
,cc.discover_date
,cc.cla_case_no
,max(rl.year_of_incident)Non_MW_Loss_Past_5
,rl.timestamp
from cla_case cc, rbn_loss rl
where cc.name_id_no = rl.customer_no
and rl.year_of_incident < trunc(cc.discover_date)
and rl.type_of_loss < 1000
and rl.timestamp < trunc(cc.discover_date)
and (cc.question_class = 20
or cc.question_class = 25)
and (trunc(cc.discover_date)- (rl.year_of_incident)) < 1095
--and (trunc(cc.discover_date) <> (rl.year_of_incident))
group by cc.cla_case_no,name_id_no, cc.discover_date,rl.timestamp
) zHere's one way:
SELECT       MIN (cla_case_no) KEEP (DENSE_RANK LAST ORDER BY r1.year_of_incident)
                     AS latest_cla_case_no
FROM       cla_case     cc
,             rbn_loss      rl
WHERE     cc.name_id_no          = rl.customer_no
AND       rl.year_of_incident     > TRUNC (cc.discover_date) - 1095
AND       rl.year_of_incident      < TRUNC (cc.discover_date)
AND       rl.type_of_loss     < 1000
AND       rl.timestamp          < TRUNC (cc.discover_date)
AND       cc.question_class     IN (20, 25)
;If you'd post some sample data (CREATE TABLE and INSERT statements) and the results you want from that data, then I could test this.
Now comes the second issue: The above is actually a subquery that will link to a bigger table via cla_case_no ccx
SELECT
ie ,(select distinct z.cla_case_no from (
select cc.name_id_no, cc.discover_date ,cc.cla_case_no, max(rl.year_of_incident)Non_MW_Loss_Past_5, rl.timestamp
from cla_case cc, rbn_loss rl
where cc.name_id_no = rl.customer_no
and rl.year_of_incident < trunc(cc.discover_date)
and rl.type_of_loss < 1000
and rl.timestamp < trunc(cc.discover_date)
and (cc.question_class = 20
or cc.question_class = 25)
and (trunc(cc.discover_date)- (rl.year_of_incident)) < 1095
--and (trunc(cc.discover_date) <> (rl.year_of_incident))
group by cc.cla_case_no,name_id_no, cc.discover_date,rl.timestamp
) z
where z.cla_case_no = ccx.cla_case_no
) Non_MW_Loss_Past_5
FROM etc
Now only certain cc.cla_case_no from the subquery will corresp to the ccx_cla_case_no from the main table and the other entries will be null.
What I require is that if the subquery returns a result that IS NOT NULL to return 'Y' ELSE 'N' instead of the varies cla_case_no's and (null) entries in the Non_MW_Loss_Past_5 column
NVL2 (x, 'Y', 'N')returns 'Y' if x is NULL, and it returns 'N' if x is not NULL. X can be a scalar sub-query:
NVL2 ((SELECT ...), 'Y', 'N')You could also use an EXISTS sub-query:
CASE
    WHEN  EXISTS (SELECT ...)
    THEN  'Y'
    ELSE  'N'
END