Analytical function help needed

Question

hi i'm using oracle 10g.
CREATE TABLE test100(
  hcim    VARCHAR2(10 BYTE),
  bcim     VARCHAR2(10 BYTE),
  num    VARCHAR2(6 BYTE),
  mindate    varchar2(10 byte))
  insert into test100 values ('03217979','03236915','76120F','10/1/2006')
  insert into test100 values ('03217979','03236916','76121F','10/1/2006')
  insert into test100 values ('03217979','03236917','76122F','10/1/2006')
  insert into test100 values ('03217979','03236918','76123F',null)
  insert into test100 values ('03217979','03236919','76124F','11/1/2009')
SELECT hcim
     , bcim
     , num
     , mindate
     , Max(TO_DATE(mindate,'MM/DD/YYYY')) OVER (PARTITION BY hcim)  AS mindate1
FROM   test100
;output:
03217979     03236915     76120F     10/1/2006     11/1/2009
03217979     03236916     76121F     10/1/2006     11/1/2009
03217979     03236919     76124F     11/1/2009     11/1/2009
03217979     03236918     76123F                  11/1/2009
03217979     03236917     76122F     10/1/2006     11/1/2009how can i show null in mindate1 column since one of the date value in mindate has a null. Only if there is no nulls then i need to show max(mindate) in mindate1
Thanks in advance

Answer 1

Hi,
Thanks for posting the CREATE TABLE and INSERT statements; that's very helpful.
Do you mean you want mindate1 to be NULL on every row for that hcim, because at least one row in that hcim had a NULL mindate? It would help if you posted the exact results you want. (I was typing this message before your message, clarifying this point, was posted.) It would also help to have a couple of different hcims in the sample data, at least one with a NULL mindate, and another where mindate is never NULL.
I think you want something like this:
SELECT hcim
     , bcim
     , num
     , mindate
     , FIRST_VALUE ( TO_DATE (mindate, 'MM/DD/YYYY')
                    ) OVER ( PARTITION BY  hcim
                        ORDER BY         TO_DATE (mindate, 'MM/DD/YYYY')     DESC     NULLS FIRST
                 )  AS mindate1
FROM   test100
;Output:
HCIM       BCIM       NUM    MINDATE    MINDATE1
03217979   03236916   76121F 10/1/2006
03217979   03236915   76120F 10/1/2006
03217979   03236917   76122F 10/1/2006
03217979   03236919   76124F 11/1/2009
03217979   03236918   76123FStoring dates in a VARCHAR2 column is a really bad idea. Why not use a DATE column? Coding will be simpler, errors will be fewer, and execution will be faster.
Edited by: Frank Kulash on Nov 11, 2011 4:53 PM